Commit Graph

2919 Commits

Author SHA1 Message Date
Dhaval Giani
b1a8c172c3 sched: fix !SYSFS build breakage
When CONFIG_SYSFS is not set, CONFIG_FAIR_USER_SCHED fails to build
with

kernel/built-in.o: In function `uids_kobject_init':
(.init.text+0x1488): undefined reference to `kernel_subsys'
kernel/built-in.o: In function `uids_kobject_init':
(.init.text+0x1490): undefined reference to `kernel_subsys'
kernel/built-in.o: In function `uids_kobject_init':
(.init.text+0x1480): undefined reference to `kernel_subsys'
kernel/built-in.o: In function `uids_kobject_init':
(.init.text+0x1494): undefined reference to `kernel_subsys'

This patch fixes this build error.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-17 16:55:11 +02:00
Ken Chen
908a7c1b9b sched: fix improper load balance across sched domain
We recently discovered a nasty performance bug in the kernel CPU load
balancer where we were hit by 50% performance regression.

When tasks are assigned to a subset of CPUs that span across
sched_domains (either ccNUMA node or the new multi-core domain) via
cpu affinity, kernel fails to perform proper load balance at
these domains, due to several logic in find_busiest_group() miss
identified busiest sched group within a given domain. This leads to
inadequate load balance and causes 50% performance hit.

To give you a concrete example, on a dual-core, 2 socket numa system,
there are 4 logical cpu, organized as:

CPU0 attaching sched-domain:
 domain 0: span 0003  groups: 0001 0002
 domain 1: span 000f  groups: 0003 000c
CPU1 attaching sched-domain:
 domain 0: span 0003  groups: 0002 0001
 domain 1: span 000f  groups: 0003 000c
CPU2 attaching sched-domain:
 domain 0: span 000c  groups: 0004 0008
 domain 1: span 000f  groups: 000c 0003
CPU3 attaching sched-domain:
 domain 0: span 000c  groups: 0008 0004
 domain 1: span 000f  groups: 000c 0003

If I run 2 tasks with CPU affinity set to 0x5.  There are situation
where cpu0 has run queue length of 2, and cpu2 will be idle.  The
kernel load balancer is unable to balance out these two tasks over
cpu0 and cpu2 due to at least three logics in find_busiest_group()
that heavily bias load balance towards power saving mode. e.g. while
determining "busiest" variable, kernel only set it when
"sum_nr_running > group_capacity".  This test is flawed that
"sum_nr_running" is not necessary same as
sum-tasks-allowed-to-run-within-the sched-group.  The end result is
that kernel "think" everything is balanced, but in reality we have an
imbalance and thus causing one CPU to be over-subscribed and leaving
other idle.  There are two other logic in the same function will also
causing similar effect.  The nastiness of this bug is that kernel not
be able to get unstuck in this unfortunate broken state.  From what
we've seen in our environment, kernel will stuck in imbalanced state
for extended period of time and it is also very easy for the kernel to
stuck into that state (it's pretty much 100% reproducible for us).

So proposing the following fix: add addition logic in
find_busiest_group to detect intrinsic imbalance within the busiest
group.  When such condition is detected, load balance goes into spread
mode instead of default grouping mode.

Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-17 16:55:11 +02:00
Milton Miller
cd79007634 sched: more robust sd-sysctl entry freeing
It occurred to me this morning that the procname field was dynamically
allocated and needed to be freed.  I started to put in break statements
when allocation failed but it was approaching 50% error handling code.

I came up with this alternative of looping while entry->mode is set and
checking proc_handler instead of ->table.  Alternatively, the string
version of the domain name and cpu number could be stored the structs.

I verified by compiling CONFIG_DEBUG_SLAB and checking the allocation
counts after taking a cpuset exclusive and back.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-17 16:55:11 +02:00
Ingo Molnar
f20bf61256 time: introduce xtime_seconds
improve performance of sys_time(). sys_time() returns time in seconds,
but it does so by calling do_gettimeofday() and then returning the
tv_sec portion of the GTOD time. But the data structure "xtime", which
is updated by every timer/scheduler tick, already offers HZ granularity
time.

the patch improves the sysbench oltp macrobenchmark by 4-5% on an AMD
dual-core system:

v2.6.23:

#threads

   1:     transactions:                        4073   (407.23 per sec.)
   2:     transactions:                        8530   (852.81 per sec.)
   3:     transactions:                        8321   (831.88 per sec.)
   4:     transactions:                        8407   (840.58 per sec.)
   5:     transactions:                        8070   (806.74 per sec.)

v2.6.23 + sys_time-speedup.patch:

   1:     transactions:                        4281   (428.09 per sec.)
   2:     transactions:                        8910   (890.85 per sec.)
   3:     transactions:                        8659   (865.79 per sec.)
   4:     transactions:                        8676   (867.34 per sec.)
   5:     transactions:                        8532   (852.91 per sec.)

and by 4-5% on an Intel dual-core system too:

2.6.23:

  1:     transactions:                        4560   (455.94 per sec.)
  2:     transactions:                        10094  (1009.30 per sec.)
  3:     transactions:                        9755   (975.36 per sec.)
  4:     transactions:                        9859   (985.78 per sec.)
  5:     transactions:                        9701   (969.72 per sec.)

2.6.23 + sys_time-speedup.patch:

  1:     transactions:                        4779   (477.84 per sec.)
  2:     transactions:                        10103  (1010.14 per sec.)
  3:     transactions:                        10141  (1013.93 per sec.)
  4:     transactions:                        10371  (1036.89 per sec.)
  5:     transactions:                        10178  (1017.50 per sec.)

(the more CPUs the system has, the more speedup this patch gives for
this particular workload.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 10:01:50 -07:00
Masami Hiramatsu
f438d914b2 kprobes: support kretprobe blacklist
Introduce architecture dependent kretprobe blacklists to prohibit users
from inserting return probes on the function in which kprobes can be
inserted but kretprobes can not.

This patch also removes "__kprobes" mark from "__switch_to" on x86_64 and
registers "__switch_to" to the blacklist on x86-64, because that mark is to
prohibit user from inserting only kretprobe.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:10 -07:00
Paul Jackson
607717a65d cpuset: remove sched domain hooks from cpusets
Remove the cpuset hooks that defined sched domains depending on the setting
of the 'cpu_exclusive' flag.

The cpu_exclusive flag can only be set on a child if it is set on the
parent.

This made that flag painfully unsuitable for use as a flag defining a
partitioning of a system.

It was entirely unobvious to a cpuset user what partitioning of sched
domains they would be causing when they set that one cpu_exclusive bit on
one cpuset, because it depended on what CPUs were in the remainder of that
cpusets siblings and child cpusets, after subtracting out other
cpu_exclusive cpusets.

Furthermore, there was no way on production systems to query the
result.

Using the cpu_exclusive flag for this was simply wrong from the get go.

Fortunately, it was sufficiently borked that so far as I know, almost no
successful use has been made of this.  One real time group did use it to
affectively isolate CPUs from any load balancing efforts.  They are willing
to adapt to alternative mechanisms for this, such as someway to manipulate
the list of isolated CPUs on a running system.  They can do without this
present cpu_exclusive based mechanism while we develop an alternative.

There is a real risk, to the best of my understanding, of users
accidentally setting up a partitioned scheduler domains, inhibiting desired
load balancing across all their CPUs, due to the nonobvious (from the
cpuset perspective) side affects of the cpu_exclusive flag.

Furthermore, since there was no way on a running system to see what one was
doing with sched domains, this change will be invisible to any using code.
Unless they have real insight to the scheduler load balancing choices, they
will be unable to detect that this change has been made in the kernel's
behaviour.

Initial discussion on lkml of this patch has generated much comment.  My
(probably controversial) take on that discussion is that it has reached a
rough concensus that the current cpuset cpu_exclusive mechanism for
defining sched domains is borked.  There is no concensus on the
replacement.  But since we can remove this mechanism, and since its
continued presence risks causing unwanted partitioning of the schedulers
load balancing, we should remove it while we can, as we proceed to work the
replacement scheduler domain mechanisms.

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:09 -07:00
Christoph Hellwig
0ac1555915 m32r: convert to generic sys_ptrace
Convert m32r to the generic sys_ptrace.  The conversion requires an
architecture hook after ptrace_attach which this patch adds.  The hook
will also be needed for a conersion of ia64 to the generic ptrace code.

Thanks to Hirokazu Takata for fixing a bug in the first version of this
code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:04 -07:00
Adam Litke
54f9f80d65 hugetlb: Add hugetlb_dynamic_pool sysctl
The maximum size of the huge page pool can be controlled using the overall
size of the hugetlb filesystem (via its 'size' mount option).  However in the
common case the this will not be set as the pool is traditionally fixed in
size at boot time.  In order to maintain the expected semantics, we need to
prevent the pool expanding by default.

This patch introduces a new sysctl controlling dynamic pool resizing.  When
this is enabled the pool will expand beyond its base size up to the size of
the hugetlb filesystem.  It is disabled by default.

Signed-off-by: Adam Litke <agl@us.ibm.com>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Dave McCracken <dave.mccracken@oracle.com>
Cc: William Irwin <bill.irwin@oracle.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Ken Chen <kenchen@google.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:02 -07:00
KAMEZAWA Hiroyuki
75884fb1c6 memory unplug: memory hotplug cleanup
A clean up patch for "scanning memory resource [start, end)" operation.

Now, find_next_system_ram() function is used in memory hotplug, but this
interface is not easy to use and codes are complicated.

This patch adds walk_memory_resouce(start,len,arg,func) function.
The function 'func' is called per valid memory resouce range in [start,pfn).

[pbadari@us.ibm.com: Error handling in walk_memory_resource()]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:01 -07:00
Mel Gorman
e12ba74d8f Group short-lived and reclaimable kernel allocations
This patch marks a number of allocations that are either short-lived such as
network buffers or are reclaimable such as inode allocations.  When something
like updatedb is called, long-lived and unmovable kernel allocations tend to
be spread throughout the address space which increases fragmentation.

This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE.  The MIGRATE_RECLAIMABLE type is for allocations that can be
reclaimed on demand, but not moved.  i.e.  they can be migrated by deleting
them and re-reading the information from elsewhere.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:00 -07:00
Christoph Lameter
0e1e7c7a73 Memoryless nodes: Use N_HIGH_MEMORY for cpusets
cpusets try to ensure that any node added to a cpuset's mems_allowed is
on-line and contains memory.  The assumption was that online nodes contained
memory.  Thus, it is possible to add memoryless nodes to a cpuset and then add
tasks to this cpuset.  This results in continuous series of oom-kill and
apparent system hang.

Change cpusets to use node_states[N_HIGH_MEMORY] [a.k.a.  node_memory_map] in
place of node_online_map when vetting memories.  Return error if admin
attempts to write a non-empty mems_allowed node mask containing only
memoryless-nodes.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:59 -07:00
Christoph Lameter
4199cfa02b Memoryless nodes: Allow profiling data to fall back to other nodes
Processors on memoryless nodes must be able to fall back to remote nodes in
order to get a profiling buffer.  This may lead to excessive NUMA traffic but
I think we should allow this rather than failing.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Bob Picco <bob.picco@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:58 -07:00
Christoph Hellwig
74a0b57627 x86: optimize page faults like all other achitectures and kill notifier cruft
x86(-64) are the last architectures still using the page fault notifier
cruft for the kprobes page fault hook.  This patch converts them to the
proper direct calls, and removes the now unused pagefault notifier bits
aswell as the cruft in kprobes.c that was related to this mess.

I know Andi didn't really like this, but all other architecture maintainers
agreed the direct calls are much better and besides the obvious cruft
removal a common way of dealing with kprobes across architectures is
important aswell.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc64]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andi Kleen <ak@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:50 -07:00
Mike Travis
d5a7430ddc Convert cpu_sibling_map to be a per cpu variable
Convert cpu_sibling_map from a static array sized by NR_CPUS to a per_cpu
variable.  This saves sizeof(cpumask_t) * NR unused cpus.  Access is mostly
from startup and CPU HOTPLUG functions.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:50 -07:00
Randy Dunlap
bfe8df3d31 slow down printk during boot
Optionally add a boot delay after each kernel printk() call, crudely
measured in milliseconds, with a maximum delay of 10 seconds per printk.

Enable CONFIG_BOOT_PRINTK_DELAY=y and then add (e.g.):
"lpj=loops_per_jiffy boot_delay=100"
to the kernel command line.

It has been useful in cases like "during boot, my machine just reboots or the
screen goes black" by slowing down printk, (and adding initcall_debug), we can
usually see the last thing that happened before the lights went out which is
usually a valuable clue.

[akpm@linux-foundation.org: not all architectures implement CONFIG_HZ]
[akpm@linux-foundation.org: fix lots of stuff]
[bunk@stusta.de: kernel/printk.c: make 2 variables static]
[heiko.carstens@de.ibm.com: fix slow down printk on boot compile error]
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:49 -07:00
Alexey Dobriyan
1bcf548293 Consolidate PTRACE_DETACH
Identical handlers of PTRACE_DETACH go into ptrace_request().
Not touching compat code.
Not touching archs that don't call ptrace_request.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:49 -07:00
Linus Torvalds
f4921aff5b Merge git://git.linux-nfs.org/pub/linux/nfs-2.6
* git://git.linux-nfs.org/pub/linux/nfs-2.6: (131 commits)
  NFSv4: Fix a typo in nfs_inode_reclaim_delegation
  NFS: Add a boot parameter to disable 64 bit inode numbers
  NFS: nfs_refresh_inode should clear cache_validity flags on success
  NFS: Fix a connectathon regression in NFSv3 and NFSv4
  NFS: Use nfs_refresh_inode() in ops that aren't expected to change the inode
  SUNRPC: Don't call xprt_release in call refresh
  SUNRPC: Don't call xprt_release() if call_allocate fails
  SUNRPC: Fix buggy UDP transmission
  [23/37] Clean up duplicate includes in
  [2.6 patch] net/sunrpc/rpcb_clnt.c: make struct rpcb_program static
  SUNRPC: Use correct type in buffer length calculations
  SUNRPC: Fix default hostname created in rpc_create()
  nfs: add server port to rpc_pipe info file
  NFS: Get rid of some obsolete macros
  NFS: Simplify filehandle revalidation
  NFS: Ensure that nfs_link() returns a hashed dentry
  NFS: Be strict about dentry revalidation when doing exclusive create
  NFS: Don't zap the readdir caches upon error
  NFS: Remove the redundant nfs_reval_fsid()
  NFSv3: Always use directory post-op attributes in nfs3_proc_lookup
  ...

Fix up trivial conflict due to sock_owned_by_user() cleanup manually in
net/sunrpc/xprtsock.c
2007-10-15 10:47:35 -07:00
Linus Torvalds
419217cb1d Merge branch 'v2.6.24-lockdep' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep
* 'v2.6.24-lockdep' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep:
  lockdep: annotate dir vs file i_mutex
  lockdep: per filesystem inode lock class
  lockdep: annotate kprobes irq fiddling
  lockdep: annotate rcu_read_{,un}lock{,_bh}
  lockdep: annotate journal_start()
  lockdep: s390: connect the sysexit hook
  lockdep: x86_64: connect the sysexit hook
  lockdep: i386: connect the sysexit hook
  lockdep: syscall exit check
  lockdep: fixup mutex annotations
  lockdep: fix mismatched lockdep_depth/curr_chain_hash
  lockdep: Avoid /proc/lockdep & lock_stat infinite output
  lockdep: maintainers
2007-10-15 10:40:41 -07:00
Ingo Molnar
9c63d9c021 sched: sync wakeups preempt too
make sure sync wakeups preempt too - the scheduler will not
overschedule as we've got various throttles against that.
As a result, sync wakeups can be used more widely in the kernel
(to signal wakeup affinity between tasks), and no arbitrary
latencies will be introduced either.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:20 +02:00
Ingo Molnar
71e20f1873 sched: affine sync wakeups
make sync wakeups affine for cache-cold tasks: if a cache-cold task
is woken up by a sync wakeup then use the opportunity to migrate it
straight away. (the two tasks are 'related' because they communicate)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Laurent Vivier
94886b84b1 sched: guest CPU accounting: maintain stats in account_system_time()
modify account_system_time() to add cputime to cpustat->guest if we are
running a VCPU. We add this cputime to cpustat->user instead of
cpustat->system because this part of KVM code is in fact user code
although it is executed in the kernel. We duplicate VCPU time between
guest and user to allow an unmodified "top(1)" to display correct value.
A modified "top(1)" is able to display good cpu user time and cpu guest
time by subtracting cpu guest time from cpu user time. Update "gtime" in
task_struct accordingly.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Acked-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Laurent Vivier
9ac52315d4 sched: guest CPU accounting: add guest-CPU /proc/<pid>/stat fields
like for cpustat, introduce the "gtime" (guest time of the task) and
"cgtime" (guest time of the task children) fields for the
tasks. Modify signal_struct and task_struct.

Modify /proc/<pid>/stat to display these new fields.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Acked-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Milton Miller
6323469f9b sched: domain sysctl fixes: add terminator comment
we had an incorrect-terminator bug in sd_alloc_ctl_domain_table()
before, so add a comment that documents it.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Milton Miller
ad1cdc1d78 sched: domain sysctl fixes: do not crash on allocation failure
Now that we are calling this at runtime, a more relaxed error path is
suggested.  If an allocation fails, we just register the partial table,
which will show empty directories.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Milton Miller
6382bc90f5 sched: domain sysctl fixes: unregister the sysctl table before domains
Unregister and free the sysctl table before destroying domains, then
rebuild and register after creating the new domains.  This prevents the
sysctl table from pointing to freed memory for root to write.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Milton Miller
97b6ea7b63 sched: domain sysctl fixes: use for_each_online_cpu()
init_sched_domain_sysctl was walking cpus 0-n and referencing per_cpu
variables.  If the cpus_possible mask is not contigious this will result
in a crash referencing unallocated data.  If the online mask is not
contigious then we would show offline cpus and miss online ones.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Milton Miller
5cf9f062c8 sched: domain sysctl fixes: use kcalloc()
kcalloc checks for n * sizeof(element) overflows and it zeros.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Arjan van de Ven
0dbee3a6b0 Make scheduler debug file operations const
In general, struct file_operations are const in the kernel, to not have
false cacheline sharing and to catch bugs at compiletime with accidental
writes to them. The new scheduler code introduces a new non-const one;
fix this up.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:19 +02:00
Ingo Molnar
6bc1665ba7 sched: allow the immediate migration of cache-cold tasks
allow the immediate migration of cache-cold tasks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Ingo Molnar
cc367732ff sched: debug, improve migration statistics
add new migration statistics when SCHED_DEBUG and SCHEDSTATS
is enabled. Available in /proc/<PID>/sched.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Ingo Molnar
2d92f22784 sched: debug: increase width of debug line
increase width of debug line - in preparation of more debugging info.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Peter Zijlstra
ff56b2f015 sched: activate task_hot() only on fair-scheduled tasks
activate task_hot() only for fair-scheduled tasks (i.e. disable it
for RT tasks).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Ingo Molnar
da84d96176 sched: reintroduce cache-hot affinity
reintroduce a simplified version of cache-hot/cold scheduling
affinity. This improves performance with certain SMP workloads,
such as sysbench.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Ingo Molnar
e5f32a3856 sched: speed up context-switches a bit
speed up context-switches a bit by not clearing p->exec_start.

(as a side-effect, this also makes p->exec_start a universal timestamp
available to cache-hot estimations.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Ingo Molnar
91c234b4e3 sched: do not wakeup-preempt with SCHED_BATCH tasks
do not wakeup-preempt with SCHED_BATCH tasks, their preemption
is batched too, driven by the tick.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Srivatsa Vaddagiri
fb7dde37ec sched: generate uevents for user creation/destruction
Generate uevents when a user is being created/destroyed. These events
can be used to configure cpu share of a new user.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Ingo Molnar
178be79348 sched: do not normalize kernel threads via SysRq-N
do not normalize kernel threads via SysRq-N: the migration threads,
softlockup threads, etc. might be essential for the system to
function properly. So only zap user tasks.

pointed out by Andi Kleen.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Andi Kleen
1666703af9 sched: remove stale comment from sched_group_set_shares()
remove stale comment from sched_group_set_shares().

Function never returns -EINVAL.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:18 +02:00
Ingo Molnar
d5036e89dc sched: clean up is_migration_thread()
clean up is_migration_thread() and turn it into an inline function.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:15 +02:00
Andi Kleen
3a5e4dc12f sched: cleanup: refactor normalize_rt_tasks
Replace a particularly ugly ifdef with an inline and a new macro.
Also split up the function to be easier to read.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:15 +02:00
Andi Kleen
8cbbe86dfc sched: cleanup: refactor common code of sleep_on / wait_for_completion
Refactor common code of sleep_on / wait_for_completion

These functions were largely cut'n'pasted. This moves
the common code into single helpers instead.  Advantage
is about 1k less code on x86-64 and 91 lines of code removed.
It adds one function call to the non timeout version of
the functions; i don't expect this to be measurable.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Andi Kleen
3a5c359a58 sched: cleanup: remove unnecessary gotos
Replace loops implemented with gotos with real loops.
Replace err = ...; goto x; x: return err; with return ...;

No functional changes.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Ingo Molnar
d274a4cee1 sched: update comment
update comment: clarify time-slices and remove obsolete tuning detail.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Mike Galbraith
95938a35c5 sched: prevent wakeup over-scheduling
Prevent wakeup over-scheduling.  Once a task has been preempted by a
task of the same or lower priority, it becomes ineligible for repeated
preemption by same until it has been ticked, or slept.  Instead, the
task is marked for preemption at the next tick.  Tasks of higher
priority still preempt immediately.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Peter Zijlstra
ce6c131131 sched: disable forced preemption by default
Implement feature bit to disable forced preemption. This way
it can be checked whether a workload is overscheduling or not.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Dmitry Adamushko
e62dd02ed0 sched: fix group scheduling for SCHED_BATCH
The following patch (sched: disable sleeper_fairness on SCHED_BATCH)
seems to break GROUP_SCHED. Although, it may be 'oops'-less due to the
possibility of 'p' being always a valid address.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Zou Nan hai
ace8b3d633 sched: some proc entries are missed in sched_domain sys_ctl debug code
cache_nice_tries and flags entry do not appear in proc fs sched_domain
directory, because ctl_table entry is skipped.

This patch fixes the issue.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Gautham R Shenoy
638e13ac37 sched: fix rt ptracer monopolizing CPU
yield() in wait_task_inactive(), can cause a high priority thread to be
scheduled back in, and there by loop forever while it is waiting for some
lower priority thread which is unfortunately still on the runqueue.

Use schedule_timeout_uninterruptible(1) instead.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Credit: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Dhaval Giani
5cb350baf5 sched: group scheduling, sysfs tunables
Add tunables in sysfs to modify a user's cpu share.

A directory is created in sysfs for each new user in the system.

	/sys/kernel/uids/<uid>/cpu_share

Reading this file returns the cpu shares granted for the user.
Writing into this file modifies the cpu share for the user. Only an
administrator is allowed to modify a user's cpu share.

Ex:
	# cd /sys/kernel/uids/
	# cat 512/cpu_share
	1024
	# echo 2048 > 512/cpu_share
	# cat 512/cpu_share
	2048
	#

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Peter Zijlstra
8ca0e14ffb sched: disable sleeper_fairness on SCHED_BATCH
disable sleeper fairness for batch tasks - they are about
batch processing after all.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Peter Zijlstra
810e95ccd5 sched: another wakeup_granularity fix
unit mis-match: wakeup_gran was used against a vruntime

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Paul E. McKenney
a58f6f253d sched: export cpu_clock()
export cpu_clock() - the preferred API instead of sched_clock().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Ingo Molnar
00bf7bfc2e sched: fix: move the CPU check into ->task_new_fair()
noticed by Peter Zijlstra:

fix: move the CPU check into ->task_new_fair(), this way we
can call place_entity() and get child ->vruntime right at
initial wakeup time.

(without this there can be large latencies)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:14 +02:00
Ingo Molnar
0702e3ebc1 sched: cleanup: function prototype cleanups
noticed by Thomas Gleixner:

cleanup: function prototype cleanups - move into single line
wherever possible.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Ingo Molnar
4cf86d77f5 sched: cleanup: rename task_grp to task_group
cleanup: rename task_grp to task_group. No need to save two characters
and 'grp' is annoying to read.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:14 +02:00
Ingo Molnar
06877c33fe sched: cleanup: rename SCHED_FEAT_USE_TREE_AVG to SCHED_FEAT_TREE_AVG
cleanup: rename SCHED_FEAT_USE_TREE_AVG to SCHED_FEAT_TREE_AVG, to
make SCHED_FEAT_ names more consistent.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Ingo Molnar
a65914b365 sched: kfree(NULL) is valid
kfree(NULL) is valid.

pointed out by checkpatch.pl.

the fix shrinks the code a bit:

   text    data     bss     dec     hex filename
  40024    3842     100   43966    abbe sched.o.before
  40002    3842     100   43944    aba8 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Ingo Molnar
8927f49479 sched: style cleanup
fix up __setup() style bug - noticed via checkpatch.pl.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Ingo Molnar
26797a34a2 sched: break out if printing a warning in sched_domain_debug()
checkpatch.pl and Andy Whitcroft noticed the following bug: we did
not break out after printing an error.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Ingo Molnar
3e9830dcab sched: run sched_domain_debug() if CONFIG_SCHED_DEBUG=y
run sched_domain_debug() if CONFIG_SCHED_DEBUG=y, instead
of relying on the hand-crafted SCHED_DOMAIN_DEBUG switch.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Dmitry Adamushko
a2a2d68073 sched: cleanup, make dequeue_entity() and update_stats_wait_end() similar
make dequeue_entity() / enqueue_entity() and update_stats_dequeue() /
update_stats_enqueue() look similar, structure-wise.

zero effect, functionality-wise:

   text    data     bss     dec     hex filename
  34550    3026     100   37676    932c sched.o.before
  34550    3026     100   37676    932c sched.o.after

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Dmitry Adamushko
a03c9061d9 sched: cleanup, remove calc_weighted()
remove obsolete code -- calc_weighted()

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Dmitry Adamushko
a4ec24b48d sched: tidy up SCHED_RR
- make timeslices of SCHED_RR tasks constant and not
dependent on task's static_prio [1] ;
- remove obsolete code (timeslice related bits);
- make sched_rr_get_interval() return something more
meaningful [2] for SCHED_OTHER tasks.

[1] according to the following link, it's not compliant with SUSv3
(not sure though, what is the reference for us :-)
http://lkml.org/lkml/2007/3/7/656

[2] the interval is dynamic and can be depicted as follows "should a
task be one of the runnable tasks at this particular moment, it would
expect to run for this interval of time before being re-scheduled by the
scheduler tick".
(i.e. it's more precise if a task is runnable at the moment)

yeah, this seems to require task_rq_lock/unlock() but this is not a hot
path.

results:

(SCHED_FIFO)

dimm@earth:~/storage/prog$ sudo chrt -f 10 ./rr_interval 
time_slice: 0 : 0

(SCHED_RR)

dimm@earth:~/storage/prog$ sudo chrt 10 ./rr_interval 
time_slice: 0 : 99984800

(SCHED_NORMAL)

dimm@earth:~/storage/prog$ ./rr_interval 
time_slice: 0 : 19996960

(SCHED_NORMAL + a cpu_hog of similar 'weight' on the same CPU --- so should be a half of the previous result)

dimm@earth:~/storage/prog$ taskset 1 ./rr_interval 
time_slice: 0 : 9998480

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Alexey Dobriyan
a9957449b0 sched: uninline scheduler
* save ~300 bytes
* activate_idle_task() was moved to avoid a warning

bloat-o-meter output:

add/remove: 6/0 grow/shrink: 0/16 up/down: 438/-733 (-295)		<===
function                                     old     new   delta
__enqueue_entity                               -     165    +165
finish_task_switch                             -     110    +110
update_curr_rt                                 -      79     +79
__load_balance_iterator                        -      32     +32
__task_rq_unlock                               -      28     +28
find_process_by_pid                            -      24     +24
do_sched_setscheduler                        133     123     -10
sys_sched_rr_get_interval                    176     165     -11
sys_sched_getparam                           156     145     -11
normalize_rt_tasks                           482     470     -12
sched_getaffinity                            112      99     -13
sys_sched_getscheduler                        86      72     -14
sched_setaffinity                            226     212     -14
sched_setscheduler                           666     642     -24
load_balance_start_fair                       33       9     -24
load_balance_next_fair                        33       9     -24
dequeue_task_rt                              133      67     -66
put_prev_task_rt                              97      28     -69
schedule_tail                                133      50     -83
schedule                                     682     594     -88
enqueue_entity                               499     366    -133
task_new_fair                                317     180    -137

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Ingo Molnar
155bb293ae sched: tweak wakeup granularity
tweak wakeup granularity.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:13 +02:00
Ingo Molnar
1e81995066 sched: optimize schedule() a bit on SMP
optimize schedule() a bit on SMP, by moving the rq-clock update
outside the rq lock.

code size is the same:

      text    data     bss     dec     hex filename
     25725    2666      96   28487    6f47 sched.o.before
     25725    2666      96   28487    6f47 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:13 +02:00
Dmitry Adamushko
08ec3df510 sched: fix __pick_next_entity()
The thing is that __pick_next_entity() must never be called when
first_fair(cfs_rq) == NULL. It wouldn't be a problem, should 'run_node'
be the very first field of 'struct sched_entity' (and it's the second).

The 'nr_running != 0' check is _not_ enough, due to the fact that
'current' is not within the tree. Generic paths are ok (e.g. schedule()
as put_prev_task() is called previously)... I'm more worried about e.g.
migration_call() -> CPU_DEAD_FROZEN -> migrate_dead_tasks()... if
'current' == rq->idle, no problems.. if it's one of the SCHED_NORMAL
tasks (or imagine, some other use-cases in the future -- i.e. we should
not make outer world dependent on internal details of sched_fair class)
-- it may be "Houston, we've got a problem" case.

it's +16 bytes to the ".text". Another variant is to make 'run_node' the
first data member of 'struct sched_entity' but an additional check (se !
= NULL) is still needed in pick_next_entity().

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:13 +02:00
Ingo Molnar
647e7cac2d sched: vslice fixups for non-0 nice levels
Make vslice accurate wrt nice levels, and add some comments
while we're at it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:13 +02:00
Ingo Molnar
3a25201572 sched: whitespace cleanups
more whitespace cleanups. No code changed:

      text    data     bss     dec     hex filename
     26553    2790     288   29631    73bf sched.o.before
     26553    2790     288   29631    73bf sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Ingo Molnar
5522d5d5f7 sched: mark scheduling classes as const
mark scheduling classes as const. The speeds up the code
a bit and shrinks it:

   text    data     bss     dec     hex filename
  40027    4018     292   44337    ad31 sched.o.before
  40190    3842     292   44324    ad24 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Srivatsa Vaddagiri
b9fa3df33f sched: group scheduler, fix latency
There is a possibility that because of task of a group moving from one
cpu to another, it may gain more cpu time that desired. See 
http://marc.info/?l=linux-kernel&m=119073197730334 for details.

This is an attempt to fix that problem. Basically it simulates dequeue
of higher level entities as if they are going to sleep. Similarly it
simulate wakeup of higher level entities as if they are waking up from
sleep.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Srivatsa Vaddagiri
fad095a7b9 sched: group scheduler, fix bloat
Recent fix to check_preempt_wakeup() to check for preemption at higher
levels caused a size bloat for !CONFIG_FAIR_GROUP_SCHED.

Fix the problem.

  42277   10598     320   53195    cfcb kernel/sched.o-before_this_patch
  42216   10598     320   53134    cf8e kernel/sched.o-after_this_patch

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Srivatsa Vaddagiri
fb615581c7 sched: group scheduler, fix coding style issues
Fix coding style issues reported by Randy Dunlap and others

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Ingo Molnar
b39c5dd7f9 sched: cleanup, remove stale comment
cleanup, remove stale comment.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Peter Zijlstra
5f6d858ecc sched: speed up and simplify vslice calculations
speed up and simplify vslice calculations.

[ From: Mike Galbraith <efault@gmx.de>: build fix ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:12 +02:00
Peter Zijlstra
b0ffd246ea sched: clean up min_vruntime use
clean up min_vruntime use.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:12 +02:00
Srivatsa Vaddagiri
2830cf8c90 sched: group scheduler SMP migration fix
group scheduler SMP migration fix: use task_cfs_rq(p) to get
to the relevant fair-scheduling runqueue of a task, rq->cfs
is not the right one.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:12 +02:00
Ingo Molnar
2d72376b3a sched: clean up schedstats, cnt -> count
rename all 'cnt' fields and variables to the less yucky 'count' name.

yuckage noticed by Andrew Morton.

no change in code, other than the /proc/sched_debug bkl_count string got
a bit larger:

   text    data     bss     dec     hex filename
  38236    3506      24   41766    a326 sched.o.before
  38240    3506      24   41770    a32a sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Dmitry Adamushko
2b1e315dd2 sched: yield fix
fix yield bugs due to the current-not-in-rbtree changes: the task is
not in the rbtree so rbtree-removal is a no-no.

[ From: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>: build fix. ]

also, nice code size reduction:

kernel/sched.o:
   text    data     bss     dec     hex filename
  38323    3506      24   41853    a37d sched.o.before
  38236    3506      24   41766    a326 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Srivatsa Vaddagiri
8651a86c34 sched: group scheduler wakeup latency fix
group scheduler wakeup latency fix: when checking for preemption
we must check cross-group too, not just intra-group.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 17:00:12 +02:00
Ingo Molnar
57cb499df2 sched: remove set_leftmost()
Lee Schermerhorn noticed that set_leftmost() contains dead code,
remove this.

Reported-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:11 +02:00
Hiroshi Shimamoto
2ddbf95250 sched: clean up sched_fork()
The adjusting sched_class is a missing part of the already existing "do
not leak PI boosting priority to the child" at the sched_fork(). This
patch moves the adjusting sched_class from wake_up_new_task() to
sched_fork().

this also shrinks the code a bit:

   text    data     bss     dec     hex filename
  40111    4018     292   44421    ad85 sched.o.before
  40102    4018     292   44412    ad7c sched.o.after

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:11 +02:00
Peter Zijlstra
368059a977 sched: max_vruntime() simplification
max_vruntime() simplification.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:11 +02:00
Ingo Molnar
02e4bac2a5 sched: fix sched_fork()
fix sched_fork(): large latencies at new task creation time because
the ->vruntime was not fixed up cross-CPU, if the parent got migrated
after the child's CPU got set up.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:11 +02:00
Ingo Molnar
b8487b9241 sched: fix sign check error in place_entity()
fix sign check error in place_entity() - we'd get excessive
latencies due to negatives being converted to large u64's.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:11 +02:00
Ingo Molnar
94359f05cb sched: undo some of the recent changes
undo some of the recent changes that are not needed after all,
such as last_min_vruntime.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:11 +02:00
Ingo Molnar
dc1f31c90c sched: remove last_min_vruntime effect
remove last_min_vruntime use - prepare to remove it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:11 +02:00
Ingo Molnar
785c29ef95 sched: remove condition from set_task_cpu()
remove condition from set_task_cpu(). Now that ->vruntime
is not global anymore, it should (and does) work fine without
it too.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:11 +02:00
Ingo Molnar
8465e792e8 sched: entity_key() fix
entity_key() fix - we'd occasionally end up with a 0 vruntime
in the !initial case.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:11 +02:00
Peter Zijlstra
ddc9729750 sched debug: check spread
debug feature: check how well we schedule within a reasonable
vruntime 'spread' range. (note that CPU overload can increase
the spread, so this is not a hard condition, but normal loads
should be within the spread.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:10 +02:00
Ingo Molnar
d822ceceda sched debug: more width for parameter printouts
more width for parameter printouts in /proc/sched_debug.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:10 +02:00
Peter Zijlstra
67e9fb2a39 sched: add vslice
add vslice: the load-dependent "virtual slice" a task should
run ideally, so that the observed latency stays within the
sched_latency window.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:10 +02:00
Ingo Molnar
1aa4731eff sched debug: print settings
print the current value of all tunables in /proc/sched_debug output.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:10 +02:00
Ingo Molnar
c18b8a7cbc sched: remove unneeded tunables
remove unneeded tunables.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:10 +02:00
S.Caglar Onur
fdd71d132b sched debug: BKL usage statistics, fix
build fix for the SCHED_DEBUG && !SCHEDSTATS case.

Signed-off-by: S.Ceglar Onur <caglar@pardus.org.tr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:10 +02:00
Ingo Molnar
b8efb56172 sched debug: BKL usage statistics
add per task and per rq BKL usage statistics.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:10 +02:00
Srivatsa Vaddagiri
24e377a832 sched: add fair-user scheduler
Enable user-id based fair group scheduling. This is useful for anyone
who wants to test the group scheduler w/o having to enable
CONFIG_CGROUPS.

A separate scheduling group (i.e struct task_grp) is automatically created for 
every new user added to the system. Upon uid change for a task, it is made to 
move to the corresponding scheduling group.

A /proc tunable (/proc/root_user_share) is also provided to tune root
user's quota of cpu bandwidth.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:09 +02:00
Srivatsa Vaddagiri
9b5b77512d sched: clean up code under CONFIG_FAIR_GROUP_SCHED
With the view of supporting user-id based fair scheduling (and not just
container-based fair scheduling), this patch renames several functions
and makes them independent of whether they are being used for container
or user-id based fair scheduling.

Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating
less-sized array for tg->cfs_rq[] and tf->se[]).

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:09 +02:00
Srivatsa Vaddagiri
75c28ace9f sched: print &rq->cfs stats
- Print &rq->cfs statistics as well (useful for group scheduling)

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:09 +02:00
Srivatsa Vaddagiri
545f3b1815 sched: print nr_running and load in /proc/sched_debug
- print nr_running and load information for cfs_rq in /proc/sched_debug

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:09 +02:00
Srivatsa Vaddagiri
72ea22f8fb sched: fix minor bug in yield
- fix a minor bug in yield (seen for CONFIG_FAIR_GROUP_SCHED),
  group scheduling would skew when yield was called.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Srivatsa Vaddagiri
83b699ed20 sched: revert recent removal of set_curr_task()
Revert removal of set_curr_task.
Use put_prev_task/set_curr_task when changing groups/policies

Signed-off-by: Srivatsa Vaddagiri < vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:08 +02:00
Ingo Molnar
edcb60a309 sched: kernel/sched_fair.c whitespace cleanups
some trivial whitespace cleanups.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Mike Galbraith
c86da3a3d4 sched: fix formatting of /proc/sched_debug
fix formatting of /proc/sched_debug

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Ingo Molnar
ef83a5714d sched: enhance debug output
enhance debug output by changing 12345678 nsecs to 12.345678 output,
this is more human-readable.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Ingo Molnar
1a75b94f7b sched: prettify /proc/sched_debug output
print the correct amount of dashes in /proc/sched_debug.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Dmitry Adamushko
f6b53205e1 sched: rework enqueue/dequeue_entity() to get rid of set_curr_task()
rework enqueue/dequeue_entity() to get rid of 
sched_class::set_curr_task(). This simplifies sched_setscheduler(), 
rt_mutex_setprio() and sched_move_tasks().

   text    data     bss     dec     hex filename
  24330    2734      20   27084    69cc sched.o.before
  24233    2730      20   26983    6967 sched.o.after

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Dmitry Adamushko
4530d7ab0f sched: simplify sched_class::yield_task()
the 'p' (task_struct) parameter in the sched_class :: yield_task() is
redundant as the caller is always the 'current'. Get rid of it.

   text    data     bss     dec     hex filename
  24341    2734      20   27095    69d7 sched.o.before
  24330    2734      20   27084    69cc sched.o.after

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Dmitry Adamushko
87fefa381e sched: optimize task_new_fair()
due to the fact that we no longer keep the 'current' within the tree, 
dequeue/enqueue_entity() is useless for the 'current' in 
task_new_fair(). We are about to reschedule and 
sched_class->put_prev_task() will put the 'current' back into the tree, 
based on its new key.

   text    data     bss     dec     hex filename
  24388    2734      20   27142    6a06 sched.o.before
  24341    2734      20   27095    69d7 sched.o.after

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Ingo Molnar
75d4ef16a6 sched: fix delay accounting performance regression
fix delay accounting performance regression - those sched_clock()
calls are not needed.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Dmitry Adamushko
30cfdcfc5f sched: do not keep current in the tree and get rid of sched_entity::fair_key
Get rid of 'sched_entity::fair_key'.

As a side effect, 'current' is not kept withing the tree for 
SCHED_NORMAL/BATCH tasks anymore. This simplifies some parts of code 
(e.g. entity_tick() and yield_task_fair()) and also somewhat optimizes 
them (e.g. a single update_curr() now vs. dequeue/enqueue() before in 
entity_tick()).

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:07 +02:00
Dmitry Adamushko
7074badbcb sched: add set_curr_task() calls
p->sched_class->set_curr_task() has to be called before 
activate_task()/enqueue_task() in rt_mutex_setprio(), 
sched_setschedule() and sched_move_task() in order to set up 
'cfs_rq->curr'. The logic of enqueueing depends on whether a task to be 
inserted is 'current' or not.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:07 +02:00
Dmitry Adamushko
d02e5ed8d5 sched: sched_setscheduler() fix
Fix a problem in the 'sched-group' patch for !CONFIG_FAIR_GROUP_SCHED.

description:

sched_setscheduler()
{
...
if (task_running()) p->sched_class->put_prev_entity();

[ this one sets up cfs_rq->curr to NULL ]

...

if (task_running) p->sched_class->set_curr_task();

[ and this one is a _NOP_ (empty) for !CONFIG_FAIR_GROUP_SCHED ]

As a result, the task continues to run with cfs_rq->curr == NULL... no 
crashes (due to checks for !NULL in place) but e.g. update_curr() 
effectively becomes a NOP... i.e. runtime statistics for this task is 
not accounted untill it's rescheduled anew.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:07 +02:00
Srivatsa Vaddagiri
29f59db3a7 sched: group-scheduler core
Add interface to control cpu bandwidth allocation to task-groups.

(not yet configurable, due to missing CONFIG_CONTAINERS)

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:07 +02:00
Mike Galbraith
119fe5e068 sched: fix SMP migration latencies
fix SMP migration latencies: the vruntimes of different CPUs are
at incompatible offsets so they have to be fixed up when migrating
a task across CPUs.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:07 +02:00
Peter Zijlstra
02e0431a3d sched: better min_vruntime tracking
Better min_vruntime tracking: update it every time 'curr' is
updated - not just when a task is enqueued into the tree.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:07 +02:00
Dmitry Adamushko
db36cc7d6d sched: clean up schedstat block in dequeue_entity()
Better placement of #ifdef CONFIG_SCHEDSTAT block in dequeue_entity().

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:06 +02:00
Ingo Molnar
bbdba7c0e1 sched: remove wait_runtime fields and features
remove wait_runtime based fields and features, now that the CFS
math has been changed over to the vruntime metric.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:06 +02:00
Ingo Molnar
e22f5bbf86 sched: remove wait_runtime limit
remove the wait_runtime-limit fields and the code depending on it, now
that the math has been changed over to rely on the vruntime metric.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:06 +02:00
Dmitry Adamushko
495eca494a sched: clean up struct load_stat
'struct load_stat' is redundant now so let's get rid of it.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:06 +02:00
Ingo Molnar
7a62eabc4d sched: debug: update exec_clock only when SCHED_DEBUG
micro-optimization: update cfs_rq->exec_clock only if
CONFIG_SCHED_DEBUG=y.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:06 +02:00
Ingo Molnar
86d9560cb6 sched: add more vruntime statistics
add more vruntime statistics.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:06 +02:00
Peter Zijlstra
9014623c0e sched: handle vruntime 64-bit overflow
Handle vruntime overflow by centering the key space around min_vruntime.

( otherwise we could overflow 64-bit vruntime in a few days with SCHED_IDLE
 tasks - or in a few years with nice +19. )

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:05 +02:00
Peter Zijlstra
94dfb5e75e sched: add tree based averages
add support for tree based vruntime averages.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:05 +02:00
Ingo Molnar
28a1f6fa2f sched: remove SCHED_FEAT_SKIP_INITIAL
remove SCHED_FEAT_SKIP_INITIAL - it was off by default and even
when enabled it never made any real difference.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:05 +02:00
Ingo Molnar
67e12eac32 sched: add se->vruntime debugging
debug se->vruntime fields.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-10-15 17:00:05 +02:00
Peter Zijlstra
aeb73b0403 sched: clean up new task placement
clean up new task placement.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-10-15 17:00:05 +02:00
Ingo Molnar
2e09bf556f sched: wakeup granularity increase
increase wakeup granularity - we were overscheduling a bit.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-10-15 17:00:05 +02:00
Ingo Molnar
5c6b5964a0 sched: simplify check_preempt() methods
simplify the check_preempt() methods.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-10-15 17:00:05 +02:00
Peter Zijlstra
6d0f0ebd06 sched: simplify adaptive latency
simplify adaptive latency.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:05 +02:00
Peter Zijlstra
4d78e7b656 sched: new task placement for vruntime
add proper new task placement for the vruntime based math too.

( note: introduces a swap() macro, but the swap token is too
  widely used in the kernel namespace for a generic version
  to be added without changing non-scheduler code - so this
  cleanup will be done separately. )

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:04 +02:00
Ingo Molnar
6cb5819514 sched: optimize vruntime based scheduling
optimize vruntime based scheduling.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:04 +02:00
Ingo Molnar
bf5c91ba8c sched: move sched_feat() definitions
move sched_feat() definitions so that it can be used sooner by generic
code too.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:04 +02:00
Ingo Molnar
e9acbff648 sched: introduce se->vruntime
introduce se->vruntime as a sum of weighted delta-exec's, and use that
as the key into the tree.

the idea to use absolute virtual time as the basic metric of scheduling
has been first raised by William Lee Irwin, advanced by Tong Li and first
prototyped by Roman Zippel in the "Really Fair Scheduler" (RFS) patchset.

also see:

   http://lkml.org/lkml/2007/9/2/76

for a simpler variant of this patch.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:04 +02:00
Ingo Molnar
08e2388aa1 sched: clean up calc_weighted()
clean up calc_weighted() - we always use the normalized shift so
it's not needed to pass that in. Also, push the non-nice0 branch
into the function.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:04 +02:00
Ingo Molnar
1091985b48 sched: speed up update_load_add/_sub()
speed up update_load_add/_sub() by not delaying the division - this
reduces CPU pipeline dependencies.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:04 +02:00
Ingo Molnar
19ccd97a03 sched: uninline __enqueue_entity()/__dequeue_entity()
suggested by Roman Zippel: uninline __enqueue_entity() and
__dequeue_entity().

this reduces code size:

      text    data     bss     dec     hex filename
     25385    2386      16   27787    6c8b sched.o.before
     25257    2386      16   27659    6c0b sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:04 +02:00
Peter Zijlstra
e59c80c5bb sched: simplify SCHED_FEAT_* code
Peter Zijlstra suggested to simplify SCHED_FEAT_* checks via the
sched_feat(x) macro.

No code changed:

   text    data     bss     dec     hex filename
   38895    3550      24   42469    a5e5 sched.o.before
   38895    3550      24   42469    a5e5 sched.o.after

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:03 +02:00
Ingo Molnar
429d43bcc0 sched: cleanup: simplify cfs_rq_curr() methods
cleanup: simplify cfs_rq_curr() methods - now that the cfs_rq->curr
pointer is unconditionally present, remove the wrappers.

  kernel/sched.o:
      text    data     bss     dec     hex filename
     11784     224    2012   14020    36c4 sched.o.before
     11784     224    2012   14020    36c4 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:03 +02:00
Ingo Molnar
62160e3f4a sched: track cfs_rq->curr on !group-scheduling too
Noticed by Roman Zippel: use cfs_rq->curr in the !group-scheduling
case too. Small micro-optimization and cleanup effect:

   text    data     bss     dec     hex filename
   36269    3482      24   39775    9b5f sched.o.before
   36177    3486      24   39687    9b07 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:03 +02:00
Ingo Molnar
53df556e06 sched: remove precise CPU load calculations #2
continued removal of precise CPU load calculations.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:03 +02:00
Ingo Molnar
a25707f3ae sched: remove precise CPU load
CPU load calculations are statistical anyway, and there's little benefit
from having it calculated on every scheduling event. So remove this code,
it gets rid of a divide from the scheduler wakeup and context-switch
fastpath.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:03 +02:00
Ingo Molnar
8ebc91d936 sched: remove stat_gran
remove the stat_gran code - it was disabled by default and it causes
unnecessary overhead.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:03 +02:00
Ingo Molnar
2bd8e6d422 sched: use constants if !CONFIG_SCHED_DEBUG
use constants if !CONFIG_SCHED_DEBUG.

this speeds up the code and reduces code-size:

    text    data     bss     dec     hex filename
   27464    3014      16   30494    771e sched.o.before
   26929    3010      20   29959    7507 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:02 +02:00
Ingo Molnar
38ad464d41 sched: uniform tunings
use the same defaults on both UP and SMP.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:02 +02:00
Ingo Molnar
eba1ed4b7e sched: debug: track maximum 'slice'
track the maximum amount of time a task has executed while
the CPU load was at least 2x. (i.e. at least two nice-0
tasks were runnable)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:02 +02:00
Ingo Molnar
a4b29ba2f7 sched: small sched_debug cleanup
small kernel/sched_debug.c cleanup - break up
multi-variable assignment.

no code changed:

   text    data     bss     dec     hex filename
   38869    3550      24   42443    a5cb sched.o.before
   38869    3550      24   42443    a5cb sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:02 +02:00
Matthias Kaehlcke
2e45874c5a sched: use list_for_each_entry_safe() in __wake_up_common()
Use list_for_each_entry_safe() instead of list_for_each_safe() in
__wake_up_common()

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:02 +02:00
Ingo Molnar
bb61c21083 sched: resched task in task_new_fair()
to get full child-runs-first semantics make sure the parent is
rescheduled.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:02 +02:00
Ingo Molnar
44142fac34 sched: fix sysctl_sched_child_runs_first flag
fix the sched_child_runs_first flag: always call into ->task_new()
if we are on the same CPU, as SCHED_OTHER tasks depend on it for
correct initial setup.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:01 +02:00
Thomas Gleixner
1595f452f3 clockevents: introduce force broadcast notifier
The 64bit SMP bootup is slightly different to the 32bit one. It enables
the boot CPU local APIC timer before all CPUs are brought up. Some AMD C1E
systems have the C1E feature flag only set in the secondary CPU. Due to
the early enable of the boot CPU local APIC timer the APIC timer is
registered as a fully functional device. When we detect the wreckage during
the bringup of the secondary CPU, we need to force the boot CPU into
broadcast mode. 

Add a new notifier reason and implement the force broadcast in the clock
events layer.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-14 22:57:45 +02:00
Al Viro
5ba253313d more low-hanging fruits - kernel, fs, lib signedness
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-14 12:41:52 -07:00
Al Viro
2b8232ce51 minimal build fixes for uml (fallout from x86 merge)
a) include/asm-um/arch can't just point to include/asm-$(SUBARCH) now
 b) arch/{i386,x86_64}/crypto are merged now
 c) subarch-obj needed changes
 d) cpufeature_64.h should pull "cpufeature_32.h", not <asm/cpufeature_32.h>
    since it can be included from asm-um/cpufeature.h
 e) in case of uml-i386 we need CONFIG_X86_32 for make and gcc, but not
    for Kconfig
 f) sysctl.c shouldn't do vdso_enabled for uml-i386 (actually, that one
    should be registered from corresponding arch/*/kernel/*, with ifdef
    going away; that's a separate patch, though).

With that and with Stephen's patch ("[PATCH net-2.6] uml: hard_header fix")
we have uml allmodconfig building both on i386 and amd64.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-13 09:57:15 -07:00
Venki Pallipadi
4a93232dab clock events: allow replacement of broadcast timer
Change the broadcast timer, if a timer with higher rating becomes available.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-12 23:04:23 +02:00
Thomas Gleixner
c8a1d398de clockevents: fix periodic broadcast for oneshot devices
The next_event member of the clock event device is used to keep track
of the next periodic event. For one shot only devices it is wrong to
clear the variable, as the next event will be based on it.

Pointed out by Ralf Baechle

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2007-10-12 23:04:06 +02:00
Thomas Gleixner
de68d9b173 clockevents: Allow build w/o run-tine usage for migration purposes
Migration aid to allow preparatory patches which introduce not yet
used parts of clock events code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2007-10-12 23:04:05 +02:00
Linus Torvalds
e86908614f Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (408 commits)
  [POWERPC] Add memchr() to the bootwrapper
  [POWERPC] Implement logging of unhandled signals
  [POWERPC] Add legacy serial support for OPB with flattened device tree
  [POWERPC] Use 1TB segments
  [POWERPC] XilinxFB: Allow fixed framebuffer base address
  [POWERPC] XilinxFB: Add support for custom screen resolution
  [POWERPC] XilinxFB: Use pdata to pass around framebuffer parameters
  [POWERPC] PCI: Add 64-bit physical address support to setup_indirect_pci
  [POWERPC] 4xx: Kilauea defconfig file
  [POWERPC] 4xx: Kilauea DTS
  [POWERPC] 4xx: Add AMCC Kilauea eval board support to platforms/40x
  [POWERPC] 4xx: Add AMCC 405EX support to cputable.c
  [POWERPC] Adjust TASK_SIZE on ppc32 systems to 3GB that are capable
  [POWERPC] Use PAGE_OFFSET to tell if an address is user/kernel in SW TLB handlers
  [POWERPC] 85xx: Enable FP emulation in MPC8560 ADS defconfig
  [POWERPC] 85xx: Killed <asm/mpc85xx.h>
  [POWERPC] 85xx: Add cpm nodes for 8541/8555 CDS
  [POWERPC] 85xx: Convert mpc8560ads to the new CPM binding.
  [POWERPC] mpc8272ads: Remove muram from the CPM reg property.
  [POWERPC] Make clockevents work on PPC601 processors
  ...

Fixed up conflict in Documentation/powerpc/booting-without-of.txt manually.
2007-10-11 21:55:47 -07:00
Olof Johansson
d0c3d534a4 [POWERPC] Implement logging of unhandled signals
Implement show_unhandled_signals sysctl + support to print when a process
is killed due to unhandled signals just as i386 and x86_64 does.

Default to having it off, unlike x86 that defaults on.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-10-12 14:05:18 +10:00
Linus Torvalds
038a5008b2 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (867 commits)
  [SKY2]: status polling loop (post merge)
  [NET]: Fix NAPI completion handling in some drivers.
  [TCP]: Limit processing lost_retrans loop to work-to-do cases
  [TCP]: Fix lost_retrans loop vs fastpath problems
  [TCP]: No need to re-count fackets_out/sacked_out at RTO
  [TCP]: Extract tcp_match_queue_to_sack from sacktag code
  [TCP]: Kill almost unused variable pcount from sacktag
  [TCP]: Fix mark_head_lost to ignore R-bit when trying to mark L
  [TCP]: Add bytes_acked (ABC) clearing to FRTO too
  [IPv6]: Update setsockopt(IPV6_MULTICAST_IF) to support RFC 3493, try2
  [NETFILTER]: x_tables: add missing ip6t_modulename aliases
  [NETFILTER]: nf_conntrack_tcp: fix connection reopening
  [QETH]: fix qeth_main.c
  [NETLINK]: fib_frontend build fixes
  [IPv6]: Export userland ND options through netlink (RDNSS support)
  [9P]: build fix with !CONFIG_SYSCTL
  [NET]: Fix dev_put() and dev_hold() comments
  [NET]: make netlink user -> kernel interface synchronious
  [NET]: unify netlink kernel socket recognition
  [NET]: cleanup 3rd argument in netlink_sendskb
  ...

Fix up conflicts manually in Documentation/feature-removal-schedule.txt
and my new least favourite crap, the "mod_devicetable" support in the
files include/linux/mod_devicetable.h and scripts/mod/file2alias.c.

(The latter files seem to be explicitly _designed_ to get conflicts when
different subsystems work with them - that have an absolutely horrid
lack of subsystem separation!)

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-11 19:40:14 -07:00
Peter Zijlstra
851a67b825 lockdep: annotate rcu_read_{,un}lock{,_bh}
lockdep annotate rcu_read_{,un}lock{,_bh} in order to catch imbalanced
usage.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2007-10-11 22:11:12 +02:00
Peter Zijlstra
b351d164e8 lockdep: syscall exit check
Provide a check to validate that we do not hold any locks when switching
back to user-space.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 22:11:12 +02:00
Peter Zijlstra
e4564f79d4 lockdep: fixup mutex annotations
The fancy mutex_lock fastpath has too many indirections to track the caller
hence all contentions are perceived to come from mutex_lock().

Avoid this by explicitly not using the fastpath code (it was disabled already
anyway).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 22:11:12 +02:00
Gregory Haskins
3aa416b07f lockdep: fix mismatched lockdep_depth/curr_chain_hash
It is possible for the current->curr_chain_key to become inconsistent with the
current index if the chain fails to validate.  The end result is that future
lock_acquire() operations may inadvertently fail to find a hit in the cache
resulting in a new node being added to the graph for every acquire.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 22:11:11 +02:00
Tim Pepper
94c61c0aef lockdep: Avoid /proc/lockdep & lock_stat infinite output
Both /proc/lockdep and /proc/lock_stat output may loop infinitely.

When a read() requests an amount of data smaller than the amount of data
that the seq_file's foo_show() outputs, the output starts looping and
outputs the "stuck" element's data infinitely.  There may be multiple
sequential calls to foo_start(), foo_next()/foo_show(), and foo_stop()
for a single open with sequential read of the file.  The _start() does not
have to start with the 0th element and _show() might be called multiple
times in a row for the same element for a given open/read of the seq_file.

Also header output should not be happening in _start().  All output should
be in _show(), which SEQ_START_TOKEN is meant to help.  Having output in
_start() may also negatively impact seq_file's seq_read() and traverse()
accounting.

Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Al Viro <viro@ftp.linux.org.uk>
2007-10-11 22:11:11 +02:00
Denis V. Lunev
cd40b7d398 [NET]: make netlink user -> kernel interface synchronious
This patch make processing netlink user -> kernel messages synchronious.
This change was inspired by the talk with Alexey Kuznetsov about current
netlink messages processing. He says that he was badly wrong when introduced 
asynchronious user -> kernel communication.

The call netlink_unicast is the only path to send message to the kernel
netlink socket. But, unfortunately, it is also used to send data to the
user.

Before this change the user message has been attached to the socket queue
and sk->sk_data_ready was called. The process has been blocked until all
pending messages were processed. The bad thing is that this processing
may occur in the arbitrary process context.

This patch changes nlk->data_ready callback to get 1 skb and force packet
processing right in the netlink_unicast.

Kernel -> user path in netlink_unicast remains untouched.

EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock
drop, but the process remains in the cycle until the message will be fully
processed. So, there is no need to use this kludges now.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 21:15:29 -07:00
Eric W. Biederman
9dd776b6d7 [NET]: Add network namespace clone & unshare support.
This patch allows you to create a new network namespace
using sys_clone, or sys_unshare.

As the network namespace is still experimental and under development
clone and unshare support is only made available when CONFIG_NET_NS is
selected at compile time.

As this patch introduces network namespace support into code paths
that exist when the CONFIG_NET is not selected there are a few
additions made to net_namespace.h to allow a few more functions
to be used when the networking stack is not compiled in.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:46 -07:00
Adrian Bunk
464771fe47 [KERNEL]: Unexport raise_softirq_irqoff
raise_softirq_irqoff no longer has any modular user.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:18 -07:00
Eric W. Biederman
b4b510290b [NET]: Support multiple network namespaces with netlink
Each netlink socket will live in exactly one network namespace,
this includes the controlling kernel sockets.

This patch updates all of the existing netlink protocols
to only support the initial network namespace.  Request
by clients in other namespaces will get -ECONREFUSED.
As they would if the kernel did not have the support for
that netlink protocol compiled in.

As each netlink protocol is updated to be multiple network
namespace safe it can register multiple kernel sockets
to acquire a presence in the rest of the network namespaces.

The implementation in af_netlink is a simple filter implementation
at hash table insertion and hash table look up time.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:09 -07:00
Robert Olsson
c45248c701 [SOFTIRQ]: Remove do_softirq() symbol export.
As noted by Christoph Hellwig, pktgen was the only user so
it can now be removed.

[ Add missing cases caught by Adrian Bunk. -DaveM ]

Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:36 -07:00
Arnaldo Carvalho de Melo
a272378d11 [KTIME]: Introduce ktime_sub_ns and ktime_sub_us
First user will be the DCCP transport networking protocol.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:12 -07:00
Jens Axboe
f5ff8422bb Fix warnings with !CONFIG_BLOCK
Hide everything in blkdev.h with CONFIG_BLOCK isn't set, and fixup
the (few) files that fail to build because they were relying on blkdev.h
pulling in extra includes for them.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10 09:25:57 +02:00
Len Brown
4f86d3a8e2 cpuidle: consolidate 2.6.22 cpuidle branch into one patch
commit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9f
Author: Len Brown <len.brown@intel.com>
Date:   Tue Oct 2 23:44:44 2007 -0400

    cpuidle: shrink diff

    processor_idle.c |  440 +++++++++++++++++++++++++++++++++++++++++--
    1 file changed, 429 insertions(+), 11 deletions(-)

    Signed-off-by: Len Brown <len.brown@intel.com>

commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209c
Author: Len Brown <len.brown@intel.com>
Date:   Wed Sep 26 02:17:55 2007 -0400

    cpuidle: reduce diff size

    Reduces the cpuidle processor_idle.c diff vs 2.6.22 from this
     processor_idle.c | 2006 ++++++++++++++++++++++++++-----------------
     1 file changed, 1219 insertions(+), 787 deletions(-)

    to this:
     processor_idle.c |  502 +++++++++++++++++++++++++++++++++++++++----
     1 file changed, 458 insertions(+), 44 deletions(-)

    ...for the purpose of making the cpuilde patch less invasive
    and easier to review.

    no functional changes.  build tested only.

    Signed-off-by: Len Brown <len.brown@intel.com>

commit 889172fc915f5a7fe20f35b133cbd205ce69bf6c
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Thu Sep 13 13:40:05 2007 -0700

    cpuidle: Retain old ACPI policy for !CONFIG_CPU_IDLE

    Retain the old policy in processor_idle, so that when CPU_IDLE is not
    configured, old C-state policy will still be used. This provides a
    clean gradual migration path from old ACPI policy to new cpuidle
    based policy.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 9544a8181edc7ecc33b3bfd69271571f98ed08bc
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Thu Sep 13 13:39:17 2007 -0700

    cpuidle: Configure governors by default

    Quoting Len "Do not give an option to users to shoot themselves in the foot".

    Remove the configurability of ladder and menu governors as they are
    needed for default policy of cpuidle. That way users will not be able to
    have cpuidle without any policy loosing all C-state power savings.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743
Author: Adam Belay <abelay@novell.com>
Date:   Tue Aug 21 18:27:07 2007 -0400

    CPUIDLE: load ACPI properly when CPUIDLE is disabled

    Change the registration return codes for when CPUIDLE
    support is not compiled into the kernel.  As a result, the ACPI
    processor driver will load properly even if CPUIDLE is unavailable.
    However, it may be possible to cleanup the ACPI processor driver further
    and eliminate some dead code paths.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit e0322e2b58dd1b12ec669bf84693efe0dc2414a8
Author: Adam Belay <abelay@novell.com>
Date:   Tue Aug 21 18:26:06 2007 -0400

    CPUIDLE: remove cpuidle_get_bm_activity()

    Remove cpuidle_get_bm_activity() and updates governors
    accordingly.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 18a6e770d5c82ba26653e53d240caa617e09e9ab
Author: Adam Belay <abelay@novell.com>
Date:   Tue Aug 21 18:25:58 2007 -0400

    CPUIDLE: max_cstate fix

    Currently max_cstate is limited to 0, resulting in no idle processor
    power management on ACPI platforms.  This patch restores the value to
    the array size.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 1fdc0887286179b40ce24bcdbde663172e205ef0
Author: Adam Belay <abelay@novell.com>
Date:   Tue Aug 21 18:25:40 2007 -0400

    CPUIDLE: handle BM detection inside the ACPI Processor driver

    Update the ACPI processor driver to detect BM activity and
    limit state entry depth internally, rather than exposing such
    requirements to CPUIDLE.  As a result, CPUIDLE can drop this
    ACPI-specific interface and become more platform independent.  BM
    activity is now handled much more aggressively than it was in the
    original implementation, so some testing coverage may be needed to
    verify that this doesn't introduce any DMA buffer under-run issues.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 0ef38840db666f48e3cdd2b769da676c57228dd9
Author: Adam Belay <abelay@novell.com>
Date:   Tue Aug 21 18:25:14 2007 -0400

    CPUIDLE: menu governor updates

    Tweak the menu governor to more effectively handle non-timer
    break events.  Non-timer break events are detected by comparing the
    actual sleep time to the expected sleep time.  In future revisions, it
    may be more reliable to use the timer data structures directly.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1
Author: Adam Belay <abelay@novell.com>
Date:   Tue Aug 21 18:24:40 2007 -0400

    CPUIDLE: fix 'current_governor' sysfs entry

    Allow the "current_governor" sysfs entry to properly handle
    input terminated with '\n'.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit df3c71559bb69b125f1a48971bf0d17f78bbdf47
Author: Len Brown <len.brown@intel.com>
Date:   Sun Aug 12 02:00:45 2007 -0400

    cpuidle: fix IA64 build (again)

    Signed-off-by: Len Brown <len.brown@intel.com>

commit a02064579e3f9530fd31baae16b1fc46b5a7bca8
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Sun Aug 12 01:39:27 2007 -0400

    cpuidle: Remove support for runtime changing of max_cstate

    Remove support for runtime changeability of max_cstate. Drivers can use
    use latency APIs.

    max_cstate can still be used as a boot time option and dmi override.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 0912a44b13adf22f5e3f607d263aed23b4910d7e
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Sun Aug 12 01:39:16 2007 -0400

    cpuidle: Remove ACPI cstate_limit calls from ipw2100

    ipw2100 already has code to use accetable_latency interfaces to limit the
    C-state. Remove the calls to acpi_set_cstate_limit and acpi_get_cstate_limit
    as they are redundant.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit c649a76e76be6bff1fd770d0a775798813a3f6e0
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Sun Aug 12 01:35:39 2007 -0400

    cpuidle: compile fix for pause and resume functions

    Fix the compilation failure when cpuidle is not compiled in.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Acked-by: Adam Belay <adam.belay@novell.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 2305a5920fb8ee6ccec1c62ade05aa8351091d71
Author: Adam Belay <abelay@novell.com>
Date:   Thu Jul 19 00:49:00 2007 -0400

    cpuidle: re-write

    Some portions have been rewritten to make the code cleaner and lighter
    weight.  The following is a list of changes:

    1.) the state name is now included in the sysfs interface
    2.) detection, hotplug, and available state modifications are handled by
    CPUIDLE drivers directly
    3.) the CPUIDLE idle handler is only ever installed when at least one
    cpuidle_device is enabled and ready
    4.) the menu governor BM code no longer overflows
    5.) the sysfs attributes are now printed as unsigned integers, avoiding
    negative values
    6.) a variety of other small cleanups

    Also, Idle drivers are no longer swappable during runtime through the
    CPUIDLE sysfs inteface.  On i386 and x86_64 most idle handlers (e.g.
    poll, mwait, halt, etc.) don't benefit from an infrastructure that
    supports multiple states, so I think using a more general case idle
    handler selection mechanism would be cleaner.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Acked-by: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit df25b6b56955714e6e24b574d88d1fd11f0c3ee5
Author: Len Brown <len.brown@intel.com>
Date:   Tue Jul 24 17:08:21 2007 -0400

    cpuidle: fix IA64 buid

    Signed-off-by: Len Brown <len.brown@intel.com>

commit fd6ada4c14488755ff7068860078c437431fbccd
Author: Adrian Bunk <bunk@stusta.de>
Date:   Mon Jul 9 11:33:13 2007 -0700

    cpuidle: static

    make cpuidle_replace_governor() static

    Signed-off-by: Adrian Bunk <bunk@stusta.de>
    Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0
Author: Adrian Bunk <bunk@stusta.de>
Date:   Tue Jul 3 00:54:40 2007 -0400

    cpuidle: static

    This patch makes the needlessly global struct menu_governor static.

    Signed-off-by: Adrian Bunk <bunk@stusta.de>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit dbf8780c6e8d572c2c273da97ed1cca7608fd999
Author: Andrew Morton <akpm@linux-foundation.org>
Date:   Tue Jul 3 00:49:14 2007 -0400

    export symbol tick_nohz_get_sleep_length

    ERROR: "tick_nohz_get_sleep_length" [drivers/cpuidle/governors/menu.ko] undefined!
    ERROR: "tick_nohz_get_idle_jiffies" [drivers/cpuidle/governors/menu.ko] undefined!

    And please be sure to get your changes to core kernel suitably reviewed.

    Cc: Adam Belay <abelay@novell.com>
    Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: john stultz <johnstul@us.ibm.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 29f0e248e7017be15f99febf9143a2cef00b2961
Author: Andrew Morton <akpm@linux-foundation.org>
Date:   Tue Jul 3 00:43:04 2007 -0400

    tick.h needs hrtimer.h

    It uses hrtimers.

    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit e40cede7d63a029e92712a3fe02faee60cc38fb4
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Tue Jul 3 00:40:34 2007 -0400

    cpuidle: first round of documentation updates

    Documentation changes based on Pavel's feedback.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 83b42be2efece386976507555c29e7773a0dfcd1
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Tue Jul 3 00:39:25 2007 -0400

    cpuidle: add rating to the governors and pick the one with highest rating by default

    Introduce a governor rating scheme to pick the right governor by default.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit d2a74b8c5e8f22def4709330d4bfc4a29209b71c
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Tue Jul 3 00:38:08 2007 -0400

    cpuidle: make cpuidle sysfs driver governor switch off by default

    Make default cpuidle sysfs to show current_governor and current_driver in
    read-only mode.  More elaborate available_governors and available_drivers with
    writeable current_governor and current_driver interface only appear with
    "cpuidle_sysfs_switch" boot parameter.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307b
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Tue Jul 3 00:37:00 2007 -0400

    cpuidle: menu governor: change the early break condition

    Change the C-state early break out algorithm in menu governor.

    We only look at early breakouts that result in wakeups shorter than idle
    state's target_residency.  If such a breakout is frequent enough, eliminate
    the particular idle state upto a timeout period.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 45a42095cf64b003b4a69be3ce7f434f97d7af51
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Tue Jul 3 00:35:38 2007 -0400

    cpuidle: fix uninitialized variable in sysfs routine

    Fix the uninitialized usage of ret.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 80dca7cdba3e6ee13eae277660873ab9584eb3be
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Tue Jul 3 00:34:16 2007 -0400

    cpuidle: reenable /proc/acpi//power interface for the time being

    Keep /proc/acpi/processor/CPU*/power around for a while as powertop depends
    on it. It will be marked deprecated and removed in future. powertop can use
    cpuidle interfaces instead.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 589c37c2646c5e3813a51255a5ee1159cb4c33fc
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Tue Jul 3 00:32:37 2007 -0400

    cpuidle: menu governor and hrtimer compile fix

    Compile fix for menu governor.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5e
Author: Len Brown <len.brown@intel.com>
Date:   Thu May 31 22:51:43 2007 -0400

    cpuidle: build fix - cpuidle vs ipw2100 module

    ERROR: "acpi_set_cstate_limit" [drivers/net/wireless/ipw2100.ko] undefined!

    Signed-off-by: Len Brown <len.brown@intel.com>

commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58
Author: Adam Belay <abelay@novell.com>
Date:   Sat Mar 24 03:47:07 2007 -0400

    cpuidle: add the 'menu' governor

    Here is my first take at implementing an idle PM governor that takes
    full advantage of NO_HZ.  I call it the 'menu' governor because it
    considers the full list of idle states before each entry.

    I've kept the implementation fairly simple.  It attempts to guess the
    next residency time and then chooses a state that would meet at least
    the break-even point between power savings and entry cost.  To this end,
    it selects the deepest idle state that satisfies the following
    constraints:
         1. If the idle time elapsed since bus master activity was detected
            is below a threshold (currently 20 ms), then limit the selection
            to C2-type or above.
         2. Do not choose a state with a break-even residency that exceeds
            the expected time remaining until the next timer interrupt.
         3. Do not choose a state with a break-even residency that exceeds
            the elapsed time between the last pair of break events,
            excluding timer interrupts.

    This governor has an advantage over "ladder" governor because it
    proactively checks how much time remains until the next timer interrupt
    using the tick infrastructure.  Also, it handles device interrupt
    activity more intelligently by not including timer interrupts in break
    event calculations.  Finally, it doesn't make policy decisions using the
    number of state entries, which can have variable residency times (NO_HZ
    makes these potentially very large), and instead only considers sleep
    time deltas.

    The menu governor can be selected during runtime using the cpuidle sysfs
    interface like so:
    "echo "menu" > /sys/devices/system/cpu/cpuidle/current_governor"

    Signed-off-by: Adam Belay <abelay@novell.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit a4bec7e65aa3b7488b879d971651cc99a6c410fe
Author: Adam Belay <abelay@novell.com>
Date:   Sat Mar 24 03:47:03 2007 -0400

    cpuidle: export time until next timer interrupt using NO_HZ

    Expose information about the time remaining until the next
    timer interrupt expires by utilizing the dynticks infrastructure.
    Also modify the main idle loop to allow dynticks to handle
    non-interrupt break events (e.g. DMA).  Finally, expose sleep ticks
    information to external code.  Thomas Gleixner is responsible for much
    of the code in this patch.  However, I've made some additional changes,
    so I'm probably responsible if there are any bugs or oversights :)

    Signed-off-by: Adam Belay <abelay@novell.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72
Author: Adam Belay <abelay@novell.com>
Date:   Sat Mar 24 03:46:58 2007 -0400

    cpuidle: governor API changes

    This patch prepares cpuidle for the menu governor.  It adds an optional
    stage after idle state entry to give the governor an opportunity to
    check why the state was exited.  Also it makes sure the idle loop
    returns after each state entry, allowing the appropriate dynticks code
    to run.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 3a7fd42f9825c3b03e364ca59baa751bb350775f
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Thu Apr 26 00:03:59 2007 -0700

    cpuidle: hang fix

    Prevent hang on x86-64, when ACPI processor driver is added as a module on
    a system that does not support C-states.

    x86-64 expects all idle handlers to enable interrupts before returning from
    idle handler.  This is due to enter_idle(), exit_idle() races.  Make
    cpuidle_idle_call() confirm to this when there is no pm_idle_old.

    Also, cpuidle look at the return values of attch_driver() and set
    current_driver to NULL if attach fails on all CPUs.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 4893339a142afbd5b7c01ffadfd53d14746e858e
Author: Shaohua Li <shaohua.li@intel.com>
Date:   Thu Apr 26 10:40:09 2007 +0800

    cpuidle: add support for max_cstate limit

    With CPUIDLE framework, the max_cstate (to limit max cpu c-state)
    parameter is ingored. Some systems require it to ignore C2/C3
    and some drivers like ipw require it too.

    Signed-off-by: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1
Author: Shaohua Li <shaohua.li@intel.com>
Date:   Thu Apr 26 10:40:13 2007 +0800

    cpuidle: add cpuidle_fore_redetect_devices API

    add cpuidle_force_redetect_devices API,
    which forces all CPU redetect idle states.
    Next patch will use it.

    Signed-off-by: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit d1edadd608f24836def5ec483d2edccfb37b1d19
Author: Shaohua Li <shaohua.li@intel.com>
Date:   Thu Apr 26 10:40:01 2007 +0800

    cpuidle: fix sysfs related issue

    Fix the cpuidle sysfs issue.
    a. make kobject dynamicaly allocated
    b. fixed sysfs init issue to avoid suspend/resume issue

    Signed-off-by: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 7169a5cc0d67b263978859672e86c13c23a5570d
Author: Randy Dunlap <randy.dunlap@oracle.com>
Date:   Wed Mar 28 22:52:53 2007 -0400

    cpuidle: 1-bit field must be unsigned

    A 1-bit bitfield has no room for a sign bit.
    drivers/cpuidle/governors/ladder.c:54:16: error: dubious bitfield without explicit `signed' or `unsigned'

    Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
    Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Wed Mar 28 22:52:41 2007 -0400

    cpuidle: fix boot hang

    Patch for cpuidle boot hang reported by Larry Finger here.
    http://www.ussg.iu.edu/hypermail/linux/kernel/0703.2/2025.html

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Cc: Larry Finger <larry.finger@lwfinger.net>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9
Author: Len Brown <len.brown@intel.com>
Date:   Wed Mar 7 04:37:53 2007 -0500

    cpuidle: ladder does not depend on ACPI

    build fix for CONFIG_ACPI=n

    In file included from drivers/cpuidle/governors/ladder.c:21:
    include/acpi/processor.h:88: error: expected specifier-qualifier-list before ‘acpi_integer’
    include/acpi/processor.h:106: error: expected specifier-qualifier-list before ‘acpi_integer’
    include/acpi/processor.h:168: error: expected specifier-qualifier-list before ‘acpi_handle’

    Signed-off-by: Len Brown <len.brown@intel.com>

commit 8c91d958246bde68db0c3f0c57b535962ce861cb
Author: Adrian Bunk <bunk@stusta.de>
Date:   Tue Mar 6 02:29:40 2007 -0800

    cpuidle: make code static

    This patch makes the following needlessly global code static:
    - driver.c: __cpuidle_find_driver()
    - governor.c: __cpuidle_find_governor()
    - ladder.c: struct ladder_governor

    Signed-off-by: Adrian Bunk <bunk@stusta.de>
    Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Cc: Adam Belay <abelay@novell.com>
    Cc: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 0c39dc3187094c72c33ab65a64d2017b21f372d2
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Wed Mar 7 02:38:22 2007 -0500

    cpu_idle: fix build break

    This patch fixes a build breakage with !CONFIG_HOTPLUG_CPU and
    CONFIG_CPU_IDLE.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Adrian Bunk <bunk@stusta.de>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 8112e3b115659b07df340ef170515799c0105f82
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Tue Mar 6 02:29:39 2007 -0800

    cpuidle: build fix for !CPU_IDLE

    Fix the compile issues when CPU_IDLE is not configured.

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Cc: Adam Belay <abelay@novell.com>
    Cc: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 1eb4431e9599cd25e0d9872f3c2c8986821839dd
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Thu Feb 22 13:54:57 2007 -0800

    cpuidle take2: Basic documentation for cpuidle

    Documentation for cpuidle infrastructure

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Adam Belay <abelay@novell.com>
    Signed-off-by: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit ef5f15a8b79123a047285ec2e3899108661df779
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Thu Feb 22 13:54:03 2007 -0800

    cpuidle take2: Hookup ACPI C-states driver with cpuidle

    Hookup ACPI C-states onto generic cpuidle infrastructure.

    drivers/acpi/procesor_idle.c is now a ACPI C-states driver that registers as
    a driver in cpuidle infrastructure and the policy part is removed from
    drivers/acpi/processor_idle.c. We use governor in cpuidle instead.

    Signed-off-by: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Adam Belay <abelay@novell.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

commit 987196fa82d4db52c407e8c9d5dec884ba602183
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date:   Thu Feb 22 13:52:57 2007 -0800

    cpuidle take2: Core cpuidle infrastructure

    Announcing 'cpuidle', a new CPU power management infrastructure to manage
    idle CPUs in a clean and efficient manner.
    cpuidle separates out the drivers that can provide support for multiple types
    of idle states and policy governors that decide on what idle state to use
    at run time.
    A cpuidle driver can support multiple idle states based on parameters like
    varying power consumption, wakeup latency, etc (ACPI C-states for example).
    A cpuidle governor can be usage model specific (laptop, server,
    laptop on battery etc).
    Main advantage of the infrastructure being, it allows independent development
    of drivers and governors and allows for better CPU power management.

    A huge thanks to Adam Belay and Shaohua Li who were part of this mini-project
    since its beginning and are greatly responsible for this patchset.

    This patch:

    Core cpuidle infrastructure.
    Introduces a new abstraction layer for cpuidle:
    * which manages drivers that can support multiple idles states. Drivers
      can be generic or particular to specific hardware/platform
    * allows pluging in multiple policy governors that can take idle state policy
      decision
    * The core also has a set of sysfs interfaces with which administrato can know
      about supported drivers and governors and switch them at run time.

    Signed-off-by: Adam Belay <abelay@novell.com>
    Signed-off-by: Shaohua Li <shaohua.li@intel.com>
    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Len Brown <len.brown@intel.com>

Signed-off-by: Len Brown <len.brown@intel.com>
2007-10-10 00:12:41 -04:00
Trond Myklebust
50e437d522 SUNRPC: Convert rpc_pipefs to use the generic filesystem notification hooks
This will allow rpc.gssd to use inotify instead of dnotify in order to
locate new rpc upcall pipes.

This also requires the exporting of __audit_inode_child(), which is used by
fsnotify_create() and fsnotify_mkdir(). Ccing David Woodhouse.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:15:26 -04:00
Al Viro
291041e935 fix bogus reporting of signals by audit
Async signals should not be reported as sent by current in audit log.  As
it is, we call audit_signal_info() too early in check_kill_permission().
Note that check_kill_permission() has that test already - it needs to know
if it should apply current-based permission checks.  So the solution is to
move the call of audit_signal_info() between those.

Bogosity in question is easily reproduced - add a rule watching for e.g.
kill(2) from specific process (so that audit_signal_info() would not
short-circuit to nothing), say load_policy, watch the bogus OBJ_PID entry
in audit logs claiming that write(2) on selinuxfs file issued by
load_policy(8) had somehow managed to send a signal to syslogd...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-07 16:28:43 -07:00
Anton Blanchard
74922be148 Fix timer_stats printout of events/sec
When using /proc/timer_stats on ppc64 I noticed the events/sec field wasnt
accurate.  Sometimes the integer part was incorrect due to rounding (we
werent taking the fractional seconds into consideration).

The fraction part is also wrong, we need to pad the printf statement and
take the bottom three digits of 1000 times the value.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-07 16:28:43 -07:00
Ingo Molnar
30084fbd1c sched: fix profile=sleep
fix sleep profiling - we lost this chunk in the CFS merge.

Found-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-02 14:13:08 +02:00
Martin Schwidefsky
9f96cb1e8b robust futex thread exit race
Calling handle_futex_death in exit_robust_list for the different robust
mutexes of a thread basically frees the mutex.  Another thread might grab
the lock immediately which updates the next pointer of the mutex.
fetch_robust_entry over the next pointer might therefore branch into the
robust mutex list of a different thread.  This can cause two problems: 1)
some mutexes held by the dead thread are not getting freed and 2) some
mutexs held by a different thread are freed.

The next point need to be read before calling handle_futex_death.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-01 07:52:23 -07:00
Mark Lord
4047727e5a Fix SMP poweroff hangs
We need to disable all CPUs other than the boot CPU (usually 0) before
attempting to power-off modern SMP machines.  This fixes the
hang-on-poweroff issue on my MythTV SMP box, and also on Thomas Gleixner's
new toybox.

Signed-off-by: Mark Lord <mlord@pobox.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-01 07:52:23 -07:00
Al Viro
459685c75b hibernation doesn't even build on frv - tons of helpers are missing
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-By: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-26 09:22:04 -07:00
Thomas Gleixner
b7e113dc9d clockevents: remove the suspend/resume workaround^Wthinko
In a desparate attempt to fix the suspend/resume problem on Andrews
VAIO I added a workaround which enforced the broadcast of the oneshot
timer on resume. This was actually resolving the problem on the VAIO
but was just a stupid workaround, which was not tackling the root
cause: the assignement of lower idle C-States in the ACPI processor_idle
code. The cpuidle patches, which utilize the dynamic tick feature and
go faster into deeper C-states exposed the problem again. The correct
solution is the previous patch, which prevents lower C-states across
the suspend/resume.

Remove the enforcement code, including the conditional broadcast timer
arming, which helped to pamper over the real problem for quite a time.
The oneshot broadcast flag for the cpu, which runs the resume code can
never be set at the time when this code is executed. It only gets set,
when the CPU is entering a lower idle C-State.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-22 17:15:34 -07:00
Davide Libenzi
b8fceee17a signalfd simplification
This simplifies signalfd code, by avoiding it to remain attached to the
sighand during its lifetime.

In this way, the signalfd remain attached to the sighand only during
poll(2) (and select and epoll) and read(2).  This also allows to remove
all the custom "tsk == current" checks in kernel/signal.c, since
dequeue_signal() will only be called by "current".

I think this is also what Ben was suggesting time ago.

The external effect of this, is that a thread can extract only its own
private signals and the group ones.  I think this is an acceptable
behaviour, in that those are the signals the thread would be able to
fetch w/out signalfd.

Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-20 13:19:59 -07:00
Hiroshi Shimamoto
9c95e7319b sched: fix invalid sched_class use
When using rt_mutex, a NULL pointer dereference is occurred at
enqueue_task_rt. Here is a scenario;
1) there are two threads, the thread A is fair_sched_class and
   thread B is rt_sched_class.
2) Thread A is boosted up to rt_sched_class, because the thread A
   has a rt_mutex lock and the thread B is waiting the lock.
3) At this time, when thread A create a new thread C, the thread
   C has a rt_sched_class.
4) When doing wake_up_new_task() for the thread C, the priority
   of the thread C is out of the RT priority range, because the
   normal priority of thread A is not the RT priority. It makes
   data corruption by overflowing the rt_prio_array.
The new thread C should be fair_sched_class.

The new thread should be valid scheduler class before queuing.
This patch fixes to set the suitable scheduler class.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-09-19 23:34:46 +02:00
Ingo Molnar
1799e35d5b sched: add /proc/sys/kernel/sched_compat_yield
add /proc/sys/kernel/sched_compat_yield to make sys_sched_yield()
more agressive, by moving the yielding task to the last position
in the rbtree.

with sched_compat_yield=0:

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  2539 mingo     20   0  1576  252  204 R   50  0.0   0:02.03 loop_yield
  2541 mingo     20   0  1576  244  196 R   50  0.0   0:02.05 loop

with sched_compat_yield=1:

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  2584 mingo     20   0  1576  248  196 R   99  0.0   0:52.45 loop
  2582 mingo     20   0  1576  256  204 R    0  0.0   0:00.00 loop_yield

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-09-19 23:34:46 +02:00
Pavel Emelyanov
28f300d236 Fix user namespace exiting OOPs
It turned out, that the user namespace is released during the do_exit() in
exit_task_namespaces(), but the struct user_struct is released only during the
put_task_struct(), i.e.  MUCH later.

On debug kernels with poisoned slabs this will cause the oops in
uid_hash_remove() because the head of the chain, which resides inside the
struct user_namespace, will be already freed and poisoned.

Since the uid hash itself is required only when someone can search it, i.e.
when the namespace is alive, we can safely unhash all the user_struct-s from
it during the namespace exiting.  The subsequent free_uid() will complete the
user_struct destruction.

For example simple program

   #include <sched.h>

   char stack[2 * 1024 * 1024];

   int f(void *foo)
   {
   	return 0;
   }

   int main(void)
   {
   	clone(f, stack + 1 * 1024 * 1024, 0x10000000, 0);
   	return 0;
   }

run on kernel with CONFIG_USER_NS turned on will oops the
kernel immediately.

This was spotted during OpenVZ kernel testing.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Acked-by: "Serge E. Hallyn" <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-19 11:24:18 -07:00
Pavel Emelyanov
735de2230f Convert uid hash to hlist
Surprisingly, but (spotted by Alexey Dobriyan) the uid hash still uses
list_heads, thus occupying twice as much place as it could.  Convert it to
hlist_heads.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-19 11:24:18 -07:00
Matthias Kaehlcke
d8a4821dca kernel/user.c: Use list_for_each_entry instead of list_for_each
kernel/user.c: Convert list_for_each to list_for_each_entry in
uid_hash_find()

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-19 11:24:18 -07:00
Alexey Dobriyan
efc63c4fb0 Fix UTS corruption during clone(CLONE_NEWUTS)
struct utsname is copied from master one without any exclusion.

Here is sample output from one proggie doing

	sethostname("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
	sethostname("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");

and another

	clone(,, CLONE_NEWUTS, ...)
	uname()

	hostname = 'aaaaaaaaaaaaaaaaaaaaaaaaabbbbb'
	hostname = 'bbbaaaaaaaaaaaaaaaaaaaaaaaaaaa'
	hostname = 'aaaaaaaabbbbbbbbbbbbbbbbbbbbbb'
	hostname = 'aaaaaaaaaaaaaaaaaaaaaaaaaabbbb'
	hostname = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaabb'
	hostname = 'aaabbbbbbbbbbbbbbbbbbbbbbbbbbb'
	hostname = 'bbbbbbbbbbbbbbbbaaaaaaaaaaaaaa'

Hostname is sometimes corrupted.

Yes, even _the_ simplest namespace activity had bug in it. :-(

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-19 11:24:17 -07:00
Thomas Gleixner
5e41d0d60a clockevents: prevent stale tick update on offline cpu
Taking a cpu offline removes the cpu from the online mask before the
CPU_DEAD notification is done. The clock events layer does the cleanup
of the dead CPU from the CPU_DEAD notifier chain. tick_do_timer_cpu is
used to avoid xtime lock contention by assigning the task of jiffies
xtime updates to one CPU. If a CPU is taken offline, then this
assignment becomes stale. This went unnoticed because most of the time
the offline CPU went dead before the online CPU reached __cpu_die(),
where the CPU_DEAD state is checked. In the case that the offline CPU did
not reach the DEAD state before we reach __cpu_die(), the code in there
goes to sleep for 100ms. Due to the stale time update assignment, the
system is stuck forever.

Take the assignment away when a cpu is not longer in the cpu_online_mask.
We do this in the last call to tick_nohz_stop_sched_tick() when the offline
CPU is on the way to the final play_dead() idle entry.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-09-16 15:36:43 +02:00
Thomas Gleixner
31d9b3938c clockevents: do not shutdown the oneshot broadcast device
When a cpu goes offline it is removed from the broadcast masks. If the
mask becomes empty the code shuts down the broadcast device. This is
wrong, because the broadcast device needs to be ready for the online
cpu going idle (into a c-state, which stops the local apic timer).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-09-16 15:36:43 +02:00
Thomas Gleixner
07eec6af44 clockevents: Enforce oneshot broadcast when broadcast mask is set on resume
The jinxed VAIO refuses to resume without hitting keys on the keyboard
when this is not enforced. It is unclear why the cpu ends up in a lower
C State without notifying the clock events layer, but enforcing the
oneshot broadcast here is safe.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-09-16 15:36:43 +02:00
Thomas Gleixner
6a669ee8a7 timekeeping: Prevent time going backwards on resume
Timekeeping resume adjusts xtime by adding the slept time in seconds and
resets the reference value of the clock source (clock->cycle_last).
clock->cycle last is used to calculate the delta between the last xtime
update and the readout of the clock source in __get_nsec_offset(). xtime
plus the offset is the current time. The resume code ignores the delta
which had already elapsed between the last xtime update and the actual
time of suspend. If the suspend time is short, then we can see time
going backwards on resume.

Suspend:
offs_s = clock->read() - clock->cycle_last;
now = xtime + offs_s;
timekeeping_suspend_time = read_rtc();

Resume:
sleep_time = read_rtc() - timekeeping_suspend_time;
xtime.tv_sec += sleep_time;
clock->cycle_last = clock->read();
offs_r = clock->read() - clock->cycle_last;
now = xtime + offs_r;

if sleep_time_seconds == 0 and offs_r < offs_s, then time goes
backwards.

Fix this by storing the offset from the last xtime update and add it to
xtime during resume, when we reset clock->cycle_last:

sleep_time = read_rtc() - timekeeping_suspend_time;
xtime.tv_sec += sleep_time;
xtime += offs_s;	/* Fixup xtime offset at suspend time */
clock->cycle_last = clock->read();
offs_r = clock->read() - clock->cycle_last;
now = xtime + offs_r;

Thanks to Marcelo for tracking this down on the OLPC and providing the
necessary details to analyze the root cause.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Tosatti <marcelo@kvack.org>
2007-09-16 15:36:43 +02:00
Thomas Gleixner
3be9095063 timekeeping: access rtc outside of xtime lock
Lockdep complains about the access of rtc in timekeeping_suspend
inside the interrupt disabled region of the write locked xtime lock.
Move the access outside.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <johnstul@us.ibm.com>
2007-09-16 15:36:43 +02:00
Tony Breeds
298a5df45d Fix "no_sync_cmos_clock" logic inversion in kernel/time/ntp.c
Seems to me that this timer will only get started on platforms that say
they don't want it?

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Gabriel Paubert <paubert@iram.es>
Cc: Zachary Amsden <zach@vmware.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-11 17:21:27 -07:00
Michael Ellerman
3210f0ecdb Restore call_usermodehelper_pipe() behaviour
The semantics of call_usermodehelper_pipe() used to be that it would fork
the helper, and wait for the kernel thread to be started.  This was
implemented by setting sub_info.wait to 0 (implicitly), and doing a
wait_for_completion().

As part of the cleanup done in 0ab4dc9227,
call_usermodehelper_pipe() was changed to pass 1 as the value for wait to
call_usermodehelper_exec().

This is equivalent to setting sub_info.wait to 1, which is a change from
the previous behaviour.  Using 1 instead of 0 causes
__call_usermodehelper() to start the kernel thread running
wait_for_helper(), rather than directly calling ____call_usermodehelper().

The end result is that the calling kernel code blocks until the user mode
helper finishes.  As the helper is expecting input on stdin, and now no one
is writing anything, everything locks up (observed in do_coredump).

The fix is to change the 1 to UMH_WAIT_EXEC (aka 0), indicating that we
want to wait for the kernel thread to be started, but not for the helper to
finish.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-11 17:21:20 -07:00
Arnd Bergmann
179c85ea53 futex_compat: fix list traversal bugs
The futex list traversal on the compat side appears to have
a bug.

It's loop termination condition compares:

        while (compat_ptr(uentry) != &head->list)

But that can't be right because "uentry" has the special
"pi" indicator bit still potentially set at bit 0.  This
is cleared by fetch_robust_entry() into the "entry"
return value.

What this seems to mean is that the list won't terminate
when list iteration gets back to the the head.  And we'll
also process the list head like a normal entry, which could
cause all kinds of problems.

So we should check for equality with "entry".  That pointer
is of the non-compat type so we have to do a little casting
to keep the compiler and sparse happy.

The same problem can in theory occur with the 'pending'
variable, although that has not been reported from users
so far.

Based on the original patch from David Miller.

Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-11 17:21:20 -07:00
Roland McGrath
7d94143291 Fix spurious syscall tracing after PTRACE_DETACH + PTRACE_ATTACH
When PTRACE_SYSCALL was used and then PTRACE_DETACH is used, the
TIF_SYSCALL_TRACE flag is left set on the formerly-traced task.  This
means that when a new tracer comes along and does PTRACE_ATTACH, it's
possible he gets a syscall tracing stop even though he's never used
PTRACE_SYSCALL.  This happens if the task was in the middle of a system
call when the second PTRACE_ATTACH was done.  The symptom is an
unexpected SIGTRAP when the tracer thinks that only SIGSTOP should have
been provoked by his ptrace calls so far.

A few machines already fixed this in ptrace_disable (i386, ia64, m68k).
But all other machines do not, and still have this bug.  On x86_64, this
constitutes a regression in IA32 compatibility support.

Since all machines now use TIF_SYSCALL_TRACE for this, I put the
clearing of TIF_SYSCALL_TRACE in the generic ptrace_detach code rather
than adding it to every other machine's ptrace_disable.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-10 18:57:47 -07:00
Peter Zijlstra
1169783085 sched: fix ideal_runtime calculations for reniced tasks
fix ideal_runtime:

  - do not scale it using niced_granularity()
    it is against sum_exec_delta, so its wall-time, not fair-time.

  - move the whole check into __check_preempt_curr_fair()
    so that wakeup preemption can also benefit from the new logic.

this also results in code size reduction:

   text    data     bss     dec     hex filename
  13391     228    1204   14823    39e7 sched.o.before
  13369     228    1204   14801    39d1 sched.o.after

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 14:32:49 +02:00
Peter Zijlstra
4a55b45036 sched: improve prev_sum_exec_runtime setting
Second preparatory patch for fix-ideal runtime:

Mark prev_sum_exec_runtime at the beginning of our run, the same spot
that adds our wait period to wait_runtime. This seems a more natural
location to do this, and it also reduces the code a bit:

   text    data     bss     dec     hex filename
  13397     228    1204   14829    39ed sched.o.before
  13391     228    1204   14823    39e7 sched.o.after

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 14:32:49 +02:00
Peter Zijlstra
7c92e54f6f sched: simplify __check_preempt_curr_fair()
Preparatory patch for fix-ideal-runtime:

simplify __check_preempt_curr_fair(): get rid of the integer return.

   text    data     bss     dec     hex filename
  13404     228    1204   14836    39f4 sched.o.before
  13393     228    1204   14825    39e9 sched.o.after

functionality is unchanged.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 14:32:49 +02:00
Ingo Molnar
cf2ab4696e sched: fix xtensa build warning
rename RSR to SRR - 'RSR' is already defined on xtensa.

found by Adrian Bunk.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 14:32:49 +02:00
Ingo Molnar
2491b2b89d sched: debug: fix sum_exec_runtime clearing
when cleaning sched-stats also clear prev_sum_exec_runtime.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 14:32:49 +02:00
Ingo Molnar
a206c07213 sched: debug: fix cfs_rq->wait_runtime accounting
the cfs_rq->wait_runtime debug/statistics counter was not maintained
properly - fix this.

this also removes some code:

   text    data     bss     dec     hex filename
  13420     228    1204   14852    3a04 sched.o.before
  13404     228    1204   14836    39f4 sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-09-05 14:32:49 +02:00
Ingo Molnar
a0dc72601d sched: fix niced_granularity() shift
fix niced_granularity(). This resulted in under-scheduling for
CPU-bound negative nice level tasks (and this in turn caused
higher than necessary latencies in nice-0 tasks).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 14:32:49 +02:00
Suresh Siddha
7fd0d2dde9 sched: fix MC/HT scheduler optimization, without breaking the FUZZ logic.
First fix the check
	if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task)
with this
	if (*imbalance < busiest_load_per_task)

As the current check is always false for nice 0 tasks (as
SCHED_LOAD_SCALE_FUZZ is same as busiest_load_per_task for nice 0
tasks).

With the above change, imbalance was getting reset to 0 in the corner
case condition, making the FUZZ logic fail. Fix it by not corrupting the
imbalance and change the imbalance, only when it finds that the HT/MC
optimization is needed.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 14:32:48 +02:00
Linus Torvalds
5e7a39275b Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: clean up task_new_fair()
  sched: small schedstat fix
  sched: fix wait_start_fair condition in update_stats_wait_end()
  sched: call update_curr() in task_tick_fair()
  sched: make the scheduler converge to the ideal latency
  sched: fix sleeper bonus limit
2007-08-31 10:52:00 -07:00
Oleg Nesterov
60187d2708 sigqueue_free: fix the race with collect_signal()
Spotted by taoyue <yue.tao@windriver.com> and Jeremy Katz <jeremy.katz@windriver.com>.

collect_signal:				sigqueue_free:

	list_del_init(&first->list);
						if (!list_empty(&q->list)) {
							// not taken
						}
						q->flags &= ~SIGQUEUE_PREALLOC;

	__sigqueue_free(first);			__sigqueue_free(q);

Now, __sigqueue_free() is called twice on the same "struct sigqueue" with the
obviously bad implications.

In particular, this double free breaks the array_cache->avail logic, so the
same sigqueue could be "allocated" twice, and the bug can manifest itself via
the "impossible" BUG_ON(!SIGQUEUE_PREALLOC) in sigqueue_free/send_sigqueue.

Hopefully this can explain these mysterious bug-reports, see

	http://marc.info/?t=118766926500003
	http://marc.info/?t=118466273000005

Alexey Dobriyan reports this patch makes the difference for the testcase, but
nobody has an access to the application which opened the problems originally.

Also, this patch removes tasklist lock/unlock, ->siglock is enough.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: taoyue <yue.tao@windriver.com>
Cc: Jeremy Katz <jeremy.katz@windriver.com>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Roland McGrath <roland@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 01:42:23 -07:00
Alexey Dobriyan
99db67bc04 userns: don't leak root user
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 01:42:23 -07:00
Jarek Poplawski
59845b1ffd request_irq: fix DEBUG_SHIRQ handling
Mariusz Kozlowski reported lockdep's warning:

> =================================
> [ INFO: inconsistent lock state ]
> 2.6.23-rc2-mm1 #7
> ---------------------------------
> inconsistent {in-hardirq-W} -> {hardirq-on-W} usage.
> ifconfig/5492 [HC0[0]:SC0[0]:HE1:SE1] takes:
>  (&tp->lock){+...}, at: [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too]
> {in-hardirq-W} state was registered at:
>   [<c0138eeb>] __lock_acquire+0x949/0x11ac
>   [<c01397e7>] lock_acquire+0x99/0xb2
>   [<c0452ff3>] _spin_lock+0x35/0x42
>   [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too]
>   [<c0147a5d>] handle_IRQ_event+0x28/0x59
>   [<c01493ca>] handle_level_irq+0xad/0x10b
>   [<c0105a13>] do_IRQ+0x93/0xd0
>   [<c010441e>] common_interrupt+0x2e/0x34
...
> other info that might help us debug this:
> 1 lock held by ifconfig/5492:
>  #0:  (rtnl_mutex){--..}, at: [<c0451778>] mutex_lock+0x1c/0x1f
>
> stack backtrace:
...
>  [<c0452ff3>] _spin_lock+0x35/0x42
>  [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too]
>  [<c01480fd>] free_irq+0x11b/0x146
>  [<de871d59>] rtl8139_close+0x8a/0x14a [8139too]
>  [<c03bde63>] dev_close+0x57/0x74
...

This shows that a driver's irq handler was running both in hard interrupt
and process contexts with irqs enabled. The latter was done during
free_irq() call and was possible only with CONFIG_DEBUG_SHIRQ enabled.
This was fixed by another patch.

But similar problem is possible with request_irq(): any locks taken from
irq handler could be vulnerable - especially with soft interrupts. This
patch fixes it by disabling local interrupts during handler's run. (It
seems, disabling softirqs should be enough, but it needs more checking
on possible races or other special cases).

Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 01:42:23 -07:00
Rafael J. Wysocki
f3de4be9d5 PM: Fix dependencies of CONFIG_SUSPEND and CONFIG_HIBERNATION
Dependencies of CONFIG_SUSPEND and CONFIG_HIBERNATION introduced by commit
296699de6b "Introduce CONFIG_SUSPEND for
suspend-to-Ram and standby" are incorrect, as they don't cover the facts that
(1) not all architectures support suspend and (2) SMP hibernation is only
possible on X86 and PPC64 (if CONFIG_PPC64_SWSUSP is set).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 01:42:22 -07:00
Oleg Nesterov
b07e35f94a setpgid(child) fails if the child was forked by sub-thread
Spotted by Marcin Kowalczyk <qrczak@knm.org.pl>.

sys_setpgid(child) fails if the child was forked by sub-thread.

Fix the "is it our child" check. The previous commit
ee0acf90d3 was not complete.

(this patch asks for the new same_thread_group() helper, but mainline doesn't
 have it yet).

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: <stable@kernel.org>
Tested-by: "Marcin 'Qrczak' Kowalczyk" <qrczak@knm.org.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 01:42:22 -07:00
Jonathan Lim
f2ab6d8889 Assign task_struct.exit_code before taskstats_exit()
taskstats.ac_exitcode is assigned to task_struct.exit_code in bacct_add_tsk()
through the following kernel function calls:

  do_exit()
    taskstats_exit()
      fill_pid()
        bacct_add_tsk()

The problem is that in do_exit(), task_struct.exit_code is set to 'code' only
after taskstats_exit() has been called.  So we need to move the assignment
before taskstats_exit().

Signed-off-by: Jonathan Lim <jlim@sgi.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 01:42:22 -07:00
Ingo Molnar
9f508f8258 sched: clean up task_new_fair()
cleanup: we have the 'se' and 'curr' entity-pointers already,
no need to use p->se and current->se.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-08-28 12:53:24 +02:00
Ingo Molnar
213c8af67f sched: small schedstat fix
small schedstat fix: the cfs_rq->wait_runtime 'sum of all runtimes'
statistics counters missed newly forked tasks and thus had a constant
negative skew. Fix this.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-08-28 12:53:24 +02:00
Ingo Molnar
b77d69db9f sched: fix wait_start_fair condition in update_stats_wait_end()
Peter Zijlstra noticed the following bug in SCHED_FEAT_SKIP_INITIAL (which
is disabled by default at the moment): it relies on se.wait_start_fair
being 0 while update_stats_wait_end() did not recognize a 0 value,
so instead of 'skipping' the initial interval we gave the new child
a maximum boost of +runtime-limit ...

(No impact on the default kernel, but nice to fix for completeness.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-08-28 12:53:24 +02:00
Ting Yang
7109c4429a sched: call update_curr() in task_tick_fair()
update the fair-clock before using it for the key value.

[ mingo@elte.hu: small cleanups. ]

Signed-off-by: Ting Yang <tingy@cs.umass.edu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-08-28 12:53:24 +02:00
Ingo Molnar
f6cf891c4d sched: make the scheduler converge to the ideal latency
de-HZ-ification of the granularity defaults unearthed a pre-existing
property of CFS: while it correctly converges to the granularity goal,
it does not prevent run-time fluctuations in the range of
[-gran ... 0 ... +gran].

With the increase of the granularity due to the removal of HZ
dependencies, this becomes visible in chew-max output (with 5 tasks
running):

 out:  28 . 27. 32 | flu:  0 .  0 | ran:    9 .   13 | per:   37 .   40
 out:  27 . 27. 32 | flu:  0 .  0 | ran:   17 .   13 | per:   44 .   40
 out:  27 . 27. 32 | flu:  0 .  0 | ran:    9 .   13 | per:   36 .   40
 out:  29 . 27. 32 | flu:  2 .  0 | ran:   17 .   13 | per:   46 .   40
 out:  28 . 27. 32 | flu:  0 .  0 | ran:    9 .   13 | per:   37 .   40
 out:  29 . 27. 32 | flu:  0 .  0 | ran:   18 .   13 | per:   47 .   40
 out:  28 . 27. 32 | flu:  0 .  0 | ran:    9 .   13 | per:   37 .   40

average slice is the ideal 13 msecs and the period is picture-perfect 40
msecs. But the 'ran' field fluctuates around 13.33 msecs and there's no
mechanism in CFS to keep that from happening: it's a perfectly valid
solution that CFS finds.

to fix this we add a granularity/preemption rule that knows about
the "target latency", which makes tasks that run longer than the ideal
latency run a bit less. The simplest approach is to simply decrease the
preemption granularity when a task overruns its ideal latency. For this
we have to track how much the task executed since its last preemption.

( this adds a new field to task_struct, but we can eliminate that
  overhead in 2.6.24 by putting all the scheduler timestamps into an
  anonymous union. )

with this change in place, chew-max output is fluctuation-less all
around:

 out:  28 . 27. 39 | flu:  0 .  2 | ran:   13 .   13 | per:   41 .   40
 out:  28 . 27. 39 | flu:  0 .  2 | ran:   13 .   13 | per:   41 .   40
 out:  28 . 27. 39 | flu:  0 .  2 | ran:   13 .   13 | per:   41 .   40
 out:  28 . 27. 39 | flu:  0 .  2 | ran:   13 .   13 | per:   41 .   40
 out:  28 . 27. 39 | flu:  0 .  1 | ran:   13 .   13 | per:   41 .   40
 out:  28 . 27. 39 | flu:  0 .  1 | ran:   13 .   13 | per:   41 .   40

this patch has no impact on any fastpath or on any globally observable
scheduling property. (unless you have sharp enough eyes to see
millisecond-level ruckles in glxgears smoothness :-)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-08-28 12:53:24 +02:00
Mike Galbraith
5f01d519e6 sched: fix sleeper bonus limit
There is an Amarok song switch time increase (regression) under
hefty load.

What is happening is that sleeper_bonus is never consumed, and only
rarely goes below runtime_limit, so for the most part, Amarok isn't
getting any bonus at all.  We're keeping sleeper_bonus right at
runtime_limit (sched_latency == sched_runtime_limit == 40ms) forever, ie
we don't consume if we're lower that that, and don't add if we're above
it.  One Amarok thread waking (or anybody else) will push us past the
threshold, so the next thread waking gets nada, but will reap pain from
the previous thread waking until we drop back to runtime_limit.  It
looks to me like under load, some random task gets a bonus, and
everybody else pays, whether deserving or not.

This diff fixed the regression for me at any load rate.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-08-28 12:53:24 +02:00
Hugh Dickins
d243769d3f fix bogus hotplug cpu warning
Fix bogus DEBUG_PREEMPT warning on x86_64, when cpu brought online after
bootup: current_is_keventd is right to note its use of smp_processor_id
is preempt-safe, but should use raw_smp_processor_id to avoid the warning.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-27 10:27:48 -07:00
Ingo Molnar
50c46637aa sched: s/sched_latency/sched_min_granularity
runtime limit and wakeup granularity used to be a function of
granularity and that was incorrect changed to sched_latency.

Fix this to make wakeup granularity a function of min-granularity,
and the runtime limit equal to latency.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-25 22:17:19 +02:00
Ingo Molnar
172ac3dbb7 sched: cleanup, sched_granularity -> sched_min_granularity
due to adaptive granularity scheduling the role of sched_granularity
has changed to "minimum granularity", so rename the variable (and the
tunable) accordingly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-08-25 18:41:53 +02:00
Peter Zijlstra
218050855e sched: adaptive scheduler granularity
Instead of specifying the preemption granularity, specify the wanted
latency. By fixing the granlarity to a constany the wakeup latency
it a function of the number of running tasks on the rq.

Invert this relation.

sysctl_sched_granularity becomes a minimum for the dynamic granularity
computed from the new sysctl_sched_latency.

Then use this latency to do more intelligent granularity decisions: if
there are fewer tasks running then we can schedule coarser. This helps
performance while still always keeping the latency target.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-25 18:41:53 +02:00
Peter Zijlstra
1fc84aaae3 sched: fix CONFIG_SCHED_DEBUG dependency of lockdep sysctls
Make the lockdep sysctls not depend on CONFIG_SCHED_DEBUG.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-25 18:41:52 +02:00
Ingo Molnar
095e56c703 sched: fix startup penalty calculation
fix task startup penalty miscalculation: sysctl_sched_granularity is
unsigned int and wait_runtime is long so we first have to convert it
to long before turning it negative ...

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-24 20:39:10 +02:00
Peter Zijlstra
ea0aa3b23a sched: simplify bonus calculation #2
current code:

 delta = calc_delta_mine(delta_exec, curr->load.weight, lw);
 delta = min((u64)delta, cfs_rq->sleeper_bonus);

Notice that this calc_delta_mine() line is exactly delta_mine, which
gives:

 delta = min((u64)delta_mine, cfs_rq->sleeper_bonus);

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-24 20:39:10 +02:00
Peter Zijlstra
a6f2994042 sched: simplify bonus calculation #1
current code:

 delta = min(cfs_rq->sleeper_bonus, (u64)delta_exec);
 delta = calc_delta_mine(delta, curr->load.weight, lw);
 delta = min((u64)delta, cfs_rq->sleeper_bonus);

drop the first min(), because we clip against sleeper_bonus in the 3rd line
again. That gives:

 delta = calc_delta_mine(delta_exec, curr->load.weight, lw);
 delta = min((u64)delta, cfs_rq->sleeper_bonus);

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-24 20:39:10 +02:00
Ingo Molnar
b2133c8b1e sched: tidy up and simplify the bonus balance
make the bonus balance more consistent: do not hand out a bonus if
there's too much in flight already, and only deduct as much from a
runner as it has the capacity. This makes the bonus engine a zero-sum
game (as intended).

this also simplifies the code:

   text    data     bss     dec     hex filename
  34770    2998      24   37792    93a0 sched.o.before
  34749    2998      24   37771    938b sched.o.after

and it also avoids overscheduling in sleep-happy workloads like
hackbench.c.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-24 20:39:10 +02:00
Dmitry Adamushko
98fbc79853 sched: optimize task_tick_rt() a bit
Mitchell Erblich suggested a quality-of-implementation change to
not requeue SCHED_RR tasks if there's only a single task on the
runqueue, by checking for rq->nr_running == 1.

provide a more efficient implementation of that, to check that
particular RT priority-queue only.

[ From: mingo@elte.hu ]

Also first requeue the task then set need_resched - results in slightly
better machine-instruction ordering. Also clean up the code a bit.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-24 20:39:10 +02:00
Sven-Thorsten Dietrich
deac4ee65a sched: simplify can_migrate_task()
Remove trivial conditional branch in Linux scheduler's
can_migrate_task() function.

   text    data     bss     dec     hex filename
   34770    2998      24   37792    93a0 sched.o.before
   34757    2998      24   37779    9393 sched.o.after

Signed-off-by: Sven-Thorsten Dietrich <sven@thebigcorporation.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-24 20:39:10 +02:00
Ingo Molnar
71fd371463 sched: remove HZ dependency from the granularity default
remove HZ dependency from the granularity default. Use 10 msec for
the base granularity, 1 msec for wakeup granularity and 25 msec for
batch wakeup granularity. (These defaults are close to the values
that the default HZ=250 setting got previously, and thus it's the
most common setting.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-24 20:39:10 +02:00
Bruce Ashfield
7c6c16f354 sched: CONFIG_SCHED_GROUP_FAIR=y fixlet
when I built with CONFIG_FAIR_GROUP_SCHED=y, I need the following change
to make things right.

[ From: mingo@elte.hu ]

this config option is not upstream-configurable right now but lets fix
this for completeness.

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-24 20:39:10 +02:00
Linus Torvalds
d0797b39dc Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: tweak the sched_runtime_limit tunable
  sched: skip updating rq's next_balance under null SD
  sched: fix broken SMT/MC optimizations
  sched: accounting regression since rc1
  sched: fix sysctl directory permissions
  sched: sched_clock_idle_[sleep|wakeup]_event()
2007-08-23 21:38:39 -07:00
Linus Torvalds
de80af4cc9 Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6:
  sysfs: don't warn on removal of a nonexistent binary file
  HOWTO: latest lxr url address changed
  HOWTO: korean translation of Documentation/HOWTO
  Fix Off-by-one in /sys/module/*/refcnt
  sysfs: fix locking in sysfs_lookup() and sysfs_rename_dir()
2007-08-23 21:34:43 -07:00
Ingo Molnar
505c0efd58 sched: tweak the sched_runtime_limit tunable
Michael Gerdau reported reniced task CPU usage weirdnesses.
Such symptoms can be caused by limit underruns so double the
sched_runtime_limit.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-23 15:18:02 +02:00
Suresh Siddha
f549da848e sched: skip updating rq's next_balance under null SD
Was playing with sched_smt_power_savings/sched_mc_power_savings and
found out that while the scheduler domains are reconstructed when sysfs
settings change, rebalance_domains() can get triggered with null domain
on other cpus, which is setting next_balance to jiffies + 60*HZ.
Resulting in no idle/busy balancing for 60 seconds.

Fix this.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-23 15:18:02 +02:00
Suresh Siddha
f8700df7c4 sched: fix broken SMT/MC optimizations
On a four package system with HT - HT load balancing optimizations were
broken.  For example, if two tasks end up running on two logical threads
of one of the packages, scheduler is not able to pull one of the tasks
to a completely idle package.

In this scenario, for nice-0 tasks, imbalance calculated by scheduler
will be 512 and find_busiest_queue() will return 0 (as each cpu's load
is 1024 > imbalance and has only one task running).

Similarly MC scheduler optimizations also get fixed with this patch.

[ mingo@elte.hu: restored fair balancing by increasing the fuzz and
                 adding it back to the power decision, without the /2
                 factor. ]

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-23 15:18:02 +02:00
Eric W. Biederman
c57baf1e1e sched: fix sysctl directory permissions
There are two remaining gotchas:

- The directories have impossible permissions (writeable).

- The ctl_name for the kernel directory is inconsistent with
  everything else.  It should be CTL_KERN.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-23 15:18:02 +02:00
Ingo Molnar
2aa44d0567 sched: sched_clock_idle_[sleep|wakeup]_event()
construct a more or less wall-clock time out of sched_clock(), by
using ACPI-idle's existing knowledge about how much time we spent
idling. This allows the rq clock to work around TSC-stops-in-C2,
TSC-gets-corrupted-in-C3 type of problems.

( Besides the scheduler's statistics this also benefits blktrace and
  printk-timestamps as well. )

Furthermore, the precise before-C2/C3-sleep and after-C2/C3-wakeup
callbacks allow the scheduler to get out the most of the period where
the CPU has a reliable TSC. This results in slightly more precise
task statistics.

the ACPI bits were acked by Len.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Len Brown <len.brown@intel.com>
2007-08-23 15:18:02 +02:00
Oleg Nesterov
834d216e1f signalfd: fix interaction with posix-timers
dequeue_signal:

	if (__SI_TIMER) {
		spin_unlock(&tsk->sighand->siglock);
		do_schedule_next_timer(info);
		spin_lock(&tsk->sighand->siglock);
	}

Unless tsk == curent, this is absolutely unsafe: nothing prevents tsk from
exiting. If signalfd was passed to another process, do_schedule_next_timer()
is just wrong.

Add yet another "tsk == current" check into dequeue_signal().

This patch fixes an oopsable bug, but breaks the scheduling of posix timers
if the shared __SI_TIMER signal was fetched via signalfd attached to another
sub-thread. Mostly fixed by the next patch.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:46 -07:00
Oleg Nesterov
d02479bdeb posix-timers: fix creation race
sys_timer_create() sets ->it_process and unlocks ->siglock, then checks
tmr->it_sigev_notify to define if get_task_struct() is needed.

We already passed ->it_id to the caller, another thread can delete this timer
and free its memory in between.

As a minimal fix, move this code under ->siglock, sys_timer_delete() takes it
too before calling release_posix_timer().  A proper serialization would be to
take ->it_lock, we add a partly initialized timer on posix_timers_id, not
good.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:46 -07:00
Thomas Gleixner
179394af7a posix-timers: fix deletion race
timer_delete does:
	lock_timer();
	timer->it_process = NULL;
	unlock_timer();
	release_posix_timer();

timer->it_process is checked in lock_timer() to prevent access to a
timer, which is on the way to be deleted, but the check happens after
idr_lock is dropped. This allows release_posix_timer() to delete the
timer before the lock code can check the timer:

  CPU 0				CPU 1

  lock_timer();
  timer->it_process = NULL;
  unlock_timer();
				lock_timer()
					spin_lock(idr_lock);
					timer = idr_find();
					spin_lock(timer->lock);
					spin_unlock(idr_lock);
  release_posix_timer();
	spin_lock(idr_lock);
	idr_remove(timer);
	spin_unlock(idr_lock);
	free_timer(timer);
					if (timer->......)

Change the locking to prevent this.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:45 -07:00
Andrew Morton
8b7f07155f free_irq(): fix DEBUG_SHIRQ handling
If we're going to run the handler from free_irq() then we must do it with
local irq's disabled.  Otherwise lockdep complains that the handler is taking
irq-safe spinlocks in a non-irq-safe fashion.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:44 -07:00
john stultz
187226f57f futex_unlock_pi() hurts my brain and may cause application deadlock
Avoid futex_unlock_pi returning -EFAULT (which results in deadlock), by
clearing uval before jumping to retry_locked.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:44 -07:00
Adrian Bunk
88ae704c2a kernel/auditsc.c: fix an off-by-one
This patch fixes an off-by-one in a BUG_ON() spotted by the Coverity
checker.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Amy Griffis <amy.griffis@hp.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:44 -07:00
Alexey Dobriyan
256e2fdf03 Fix Off-by-one in /sys/module/*/refcnt
sysfs internals were changed to not pin module in question.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-08-22 14:35:35 -07:00
Robin Getz
cb00e99c0a fix - ensure we don't use bootconsoles after init has been released
Gerd Hoffmann pointed out that my patch from yesterday can lead
to a null pointer dereference if the kernel is booted with no
console, and no earlyprintk defined. This fixes that issue.

Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-21 20:23:53 -07:00
Robin Getz
0c5564bd91 ensure we don't use bootconsoles after init has been released
This is a followup to the cleanups for earlyprintk patch from Gerd Hoffmann

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=69331af79cf29e26d1231152a172a1a10c2df511

This ensures that a bootconsole is unregistered if it is not replaced.
The current implementation spews garbage out the bootconsole in this case,
since the bootconsole structure is normally in the init section, and is
freed, but still used.

Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-20 22:42:01 -07:00
Christian Heim
e598fbaabd Remove double inclusion of linux/capability.h
Remove the second inclusion of linux/capability.h, which has been
introduced with "[PATCH] move capable() to capability.h" (commit
c59ede7b78)

Signed-off-by: Christian Heim <phreak@gentoo.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-19 10:12:32 -07:00
Linus Torvalds
738ddd3039 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: run_rebalance_domains: s/SCHED_IDLE/CPU_IDLE/
  sched: fix sleeper bonus
  sched: make global code static
2007-08-12 11:06:45 -07:00
Thomas Gleixner
2464286ace genirq: suppress resend of level interrupts
Level type interrupts are resent by the interrupt hardware when they are
still active at irq_enable().

Suppress the resend mechanism for interrupts marked as level.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-12 11:05:45 -07:00
Thomas Gleixner
496634217e genirq: cleanup mismerge artifact
Commit 5a43a066b1: "genirq: Allow fasteoi
handler to retrigger disabled interrupts" was erroneously applied to
handle_level_irq().  This added the irq retrigger / resend functionality
to the level irq handler.

Revert the offending bits.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-12 11:05:45 -07:00