The move_tasks() function is currently multiplexed with two distinct
capabilities:
1. attempt to move a specified amount of weighted load from one run
queue to another; and
2. attempt to move a specified number of tasks from one run queue to
another.
The first of these capabilities is used in two places, load_balance()
and load_balance_idle(), and in both of these cases the return value of
move_tasks() is used purely to decide if tasks/load were moved and no
notice of the actual number of tasks moved is taken.
The second capability is used in exactly one place,
active_load_balance(), to attempt to move exactly one task and, as
before, the return value is only used as an indicator of success or failure.
This multiplexing of sched_task() was introduced, by me, as part of the
smpnice patches and was motivated by the fact that the alternative, one
function to move specified load and one to move a single task, would
have led to two functions of roughly the same complexity as the old
move_tasks() (or the new balance_tasks()). However, the new modular
design of the new CFS scheduler allows a simpler solution to be adopted
and this patch addresses that solution by:
1. adding a new function, move_one_task(), to be used by
active_load_balance(); and
2. making move_tasks() a single purpose function that tries to move a
specified weighted load and returns 1 for success and 0 for failure.
One of the consequences of these changes is that neither move_one_task()
or the new move_tasks() care how many tasks sched_class.load_balance()
moves and this enables its interface to be simplified by returning the
amount of load moved as its result and removing the load_moved pointer
from the argument list. This helps simplify the new move_tasks() and
slightly reduces the amount of work done in each of
sched_class.load_balance()'s implementations.
Further simplification, e.g. changes to balance_tasks(), are possible
but (slightly) complicated by the special needs of load_balance_fair()
so I've left them to a later patch (if this one gets accepted).
NB Since move_tasks() gets called with two run queue locks held even
small reductions in overhead are worthwhile.
[ mingo@elte.hu ]
this change also reduces code size nicely:
text data bss dec hex filename
39216 3618 24 42858 a76a sched.o.before
39173 3618 24 42815 a73f sched.o.after
Signed-off-by: Peter Williams <pwil3058@bigpond.net.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Peter Williams suggested to flip the order of update_cpu_load(rq) with
the ->task_tick() call. This is a NOP for the current scheduler (the
two functions are independent of each other), ->task_tick() might
create some state for update_cpu_load() in the future (or in PlugSched).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
batch up the sleeper bonus sum a bit more. Anything below
sched-granularity is too small to make a practical difference
anyway.
this optimization reduces the math in high-frequency scheduling
scenarios.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
C99 6.10.3[11]: preprocessing directive within the argument list of
macro invocation => undefined behaviour. Don't do that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a couple of subtle checks which were needed to handle ptracing from
the same thread group. This was deprecated a long ago, imho this code just
complicates the understanding.
And, the "->parent->signal->flags & SIGNAL_GROUP_EXIT" check in exit_notify()
is not right. SIGNAL_GROUP_EXIT can mean exec(), not exit_group(). This means
ptracer can lose a ptraced zombie on exec(). Minor problem, but still the bug.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
the early setup function serial8250_console_early_setup() can be called
from non __init code (eg. hotpluggable serial ports like serial_cs) so
remove the __init from the call chain to avoid crashes.
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Cc: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
move the rest of the debugging/instrumentation code to under
CONFIG_SCHEDSTATS too. This reduces code size and speeds code up:
text data bss dec hex filename
33044 4122 28 37194 914a sched.o.before
32708 4122 28 36858 8ffa sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
make use of the new schedstat_set() API to eliminate two #ifdef sections.
No functional changes:
text data bss dec hex filename
29009 4122 28 33159 8187 sched.o.before
29009 4122 28 33159 8187 sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1. The only place that RTPRIO_TO_LOAD_WEIGHT() is used is in the call to
move_tasks() in the function active_load_balance() and its purpose here
is just to make sure that the load to be moved is big enough to ensure
that exactly one task is moved (if there's one available). This can be
accomplished by using ULONG_MAX instead and this allows
RTPRIO_TO_LOAD_WEIGHT() to be deleted.
2. This, in turn, allows PRIO_TO_LOAD_WEIGHT() to be deleted.
3. This allows load_weight() to be deleted which allows
TIME_SLICE_NICE_ZERO to be deleted along with the comment above it.
Signed-off-by: Peter Williams <pwil3058@bigpond.net.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Marcin Slusarz reported a ne2k-pci "hung network interface" regression.
delayed disable relies on the ability to re-trigger the interrupt in the
case that a real interrupt happens after the software disable was set.
In this case we actually disable the interrupt on the hardware level
_after_ it occurred.
On enable_irq, we need to re-trigger the interrupt. On i386 this relies
on a hardware resend mechanism (send_IPI_self()).
Actually we only need the resend for edge type interrupts. Level type
interrupts come back once enable_irq() re-enables the interrupt line.
I assume that the interrupt in question is level triggered because it is
shared and above the legacy irqs 0-15:
17: 12 IO-APIC-fasteoi eth1, eth0
Looking into the IO_APIC code, the resend via send_IPI_self() happens
unconditionally. So the resend is done for level and edge interrupts.
This makes the problem more mysterious.
The code in question lib8390.c does
disable_irq();
fiddle_with_the_network_card_hardware()
enable_irq();
The fiddle_with_the_network_card_hardware() might cause interrupts,
which are cleared in the same code path again,
Marcin found that when he disables the irq line on the hardware level
(removing the delayed disable) the card is kept alive.
So the difference is that we can get a resend on enable_irq, when an
interrupt happens during the time, where we are in the disabled region.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Coverity spotted what looks like a real possible case of using a variable
after it has been freed. The problem is in
kernel/relay.c::relay_open_buf()
If the code hits "goto free_buf;" it ends up in this code :
free_buf:
relay_destroy_buf(buf); <--- calls kfree() on 'buf'.
free_name:
kfree(tmpname);
end:
return buf; <-- use after free of 'buf'.
I read through the callers and they all handle a NULL return from this
function as an error (and hitting the 'free_buf' label only happens on
failure to chan->cb->create_buf_file(), so that looks like a clear error to
me).
The patch simply sets 'buf' to NULL after the call to
relay_destroy_buf(buf); - as far as I can see that should take care of the
problem.
The patch also corrects a reference to a documentation file while
I was at it.
Note from Mathieu: the documentation reference change should have been
done in a separate patch, but I guess no one will really care.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: "David J. Wilder" <wilder@us.ibm.com>
Tested-by: "David J. Wilder" <wilder@us.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Tom Zanussi <zanussi@us.ibm.com>
Cc: Karim Yaghmour <karim@opersys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WARNING: kernel/built-in.o(.text+0x16910): Section mismatch:
reference to .init.text: (between 'kthreadd' and 'init_waitqueue_head')
comes because kernel/kthread.c:kthreadd() is not __init but calls
kthreadd_setup() which is __init. But this is ok, because kthreadd_setup()
is only ever called at init time, and then kthreadd() proceeds into its
"for (;;)" loop. We could mark kthreadd __init_refok, but kthreadd_setup()
with just one callsite and 4 lines in it (it's been that small since
10ab825bde) doesn't need to be a separate function at all -- so let's
just move those four lines at beginning of kthreadd() itself.
Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The fourth argument of sys_futex is ignored when op == FUTEX_WAKE_OP,
but futex_wake_op expects it as its nr_wake2 parameter.
The only user of this operation in glibc is always passing 1, so this
bug had no consequences so far.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix kernel-doc warnings in sched.c:
Warning(linux-2623-rc1g4//kernel/sched.c:1685): No description found for parameter 'notifier'
Warning(linux-2623-rc1g4//kernel/sched.c:1696): No description found for parameter 'notifier'
Warning(linux-2623-rc1g4//kernel/sched.c:1750): No description found for parameter 'prev'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Restore the 2.6.22 CONFIG_ACPI_SLEEP build option, but now shadowing the
new CONFIG_PM_SLEEP option.
Signed-off-by: Len Brown <len.brown@intel.com>
[ Modified to work with the PM config setup changes. ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce CONFIG_SUSPEND representing the ability to enter system sleep
states, such as the ACPI S3 state, and allow the user to choose SUSPEND
and HIBERNATION independently of each other.
Make HOTPLUG_CPU be selected automatically if SUSPEND or HIBERNATION has
been chosen and the kernel is intended for SMP systems.
Also, introduce CONFIG_PM_SLEEP which is automatically selected if
CONFIG_SUSPEND or CONFIG_HIBERNATION is set and use it to select the
code needed for both suspend and hibernation.
The top-level power management headers and the ACPI code related to
suspend and hibernation are modified to use the new definitions (the
changes in drivers/acpi/sleep/main.c are, mostly, moving code to reduce
the number of ifdefs).
There are many other files in which CONFIG_PM can be replaced with
CONFIG_PM_SLEEP or even with CONFIG_SUSPEND, but they can be updated in
the future.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION to avoid
confusion (among other things, with CONFIG_SUSPEND introduced in the
next patch).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
copy_from_user() returns the number of bytes not copied, hence 0 is the
expected output.
axi->mm might not be valid anymore when not equal to current->mm, do not
dereference before checking that - thanks to Al for spotting that.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit bd804eba1c ("PM: Introduce
pm_power_off_prepare") caused problems in the poweroff path, as reported by
YOSHIFUJI Hideaki / 吉藤英明.
Generally, sysdev_shutdown() should be called after the ACPI preparation for
powering the system off. To make it happen, we can separate sysdev_shutdown()
from device_shutdown() and call it directly wherever necessary.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix kmod.c:
Warning(linux-2.6.23-rc1//kernel/kmod.c:364): No description found for parameter 'envp'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
debugging feature: make the sched-domains tree runtime-tweakable.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Only sched.c uses sysrq_sched_debug_show, and sched.c includes sched_debug.c,
so all uses of sysrq_sched_debug_show occur in the same source file.
Eliminates a sparse warning:
warning: symbol 'sysrq_sched_debug_show' was not declared. Should it be static?
Signed-off-by: Josh Triplett <josh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
it is enough to disable interrupts to get the precise rq-clock
of the local CPU.
this also solves an NMI watchdog regression: the NMI watchdog
calls touch_softlockup_watchdog(), which might deadlock on
rq->lock if the NMI hits an rq-locked critical section.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This adds a general mechanism whereby a task can request the scheduler to
notify it whenever it is preempted or scheduled back in. This allows the
task to swap any special-purpose registers like the fpu or Intel's VT
registers.
Signed-off-by: Avi Kivity <avi@qumranet.com>
[ mingo@elte.hu: fixes, cleanups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
ACPI: Kconfig: remove CONFIG_ACPI_SLEEP from source
ACPI: quiet ACPI Exceptions due to no _PTC or _TSS
ACPI: Remove references to ACPI_STATE_S2 from acpi_pm_enter
ACPI: Kconfig: always enable CONFIG_ACPI_SLEEP on X86
ACPI: Kconfig: fold /proc/acpi/sleep under CONFIG_ACPI_PROCFS
ACPI: Kconfig: CONFIG_ACPI_PROCFS now defaults to N
ACPI: autoload modules - Create __mod_acpi_device_table symbol for all ACPI drivers
ACPI: autoload modules - Create ACPI alias interface
ACPI: autoload modules - ACPICA modifications
ACPI: asus-laptop: Fix failure exits
ACPI: fix oops due to typo in new throttling code
ACPI: ignore _PSx method for hotplugable PCI devices
ACPI: Use ACPI methods to select PCI device suspend state
ACPI, PNP: hook ACPI D-state to PNP suspend/resume
ACPI: Add acpi_pm_device_sleep_state helper routine
ACPI: Implement the set_target() callback from pm_ops
This avoids xtime lag seen with dynticks, because while 'xtime' itself
is still not updated often, we keep a 'xtime_cache' variable around that
contains the approximate real-time that _is_ updated each time we do a
'update_wall_time()', and is thus never off by more than one tick.
IOW, this restores the original semantics for 'xtime' users, as long as
you use the proper abstraction functions (ie 'current_kernel_time()' or
'get_seconds()' depending on whether you want a timespec or just the
seconds field).
[ Updated Patch. As penance for my sins I've also yanked another #ifdef
that was added to avoid the xtime lag w/ hrtimers. ]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This avoids use of the kernel-internal "xtime" variable directly outside
of the actual time-related functions. Instead, use the helper functions
that we already have available to us.
This doesn't actually change any behaviour, but this will allow us to
fix the fact that "xtime" isn't updated very often with CONFIG_NO_HZ
(because much of the realtime information is maintained as separate
offsets to 'xtime'), which has caused interfaces that use xtime directly
to get a time that is out of sync with the real-time clock by up to a
third of a second or so.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As it was a synonym for (CONFIG_ACPI && CONFIG_X86),
the ifdefs for it were more clutter than they were worth.
For ia64, just add a few stubs in anticipation of future
S3 or S4 support.
Signed-off-by: Len Brown <len.brown@intel.com>
This patch makes the i386 behave the same way that x86_64 does when a
segfault happens. A line gets printed to the kernel log so that tools
that need to check for failures can behave more uniformly between
debug.show_unhandled_signals sysctl variable to 0 (or by doing echo 0 >
/proc/sys/debug/exception-trace)
Also, all of the lines being printed are now using printk_ratelimit() to
deny the ability of DoS from a local user with a program like the
following:
main()
{
while (1)
if (!fork()) *(int *)0 = 0;
}
This new revision also includes the fix that Andrew did which got rid of
new sysctl that was added to the system in earlier versions of this.
Also, 'show-unhandled-signals' sysctl has been renamed back to the old
'exception-trace' to avoid breakage of people's scripts.
AK: Enabling by default for i386 will be likely controversal, but let's see what happens
AK: Really folks, before complaining just fix your segfaults
AK: I bet this will find a lot of silent issues
Signed-off-by: Masoud Sharbiani <masouds@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
[ Personally, I've found the complaints useful on x86-64, so I'm all for
this. That said, I wonder if we could do it more prettily.. -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Selinux folks had been complaining about the lack of AVC_PATH
records when audit is disabled. I must admit my stupidity - I assumed
that avc_audit() really couldn't use audit_log_d_path() because of
deadlocks (== could be called with dcache_lock or vfsmount_lock held).
Shouldn't have made that assumption - it never gets called that way.
It _is_ called under spinlocks, but not those.
Since audit_log_d_path() uses ab->gfp_mask for allocations,
kmalloc() in there is not a problem. IOW, the simple fix is sufficient:
let's rip AUDIT_AVC_PATH out and simply generate pathname as part of main
record. It's trivial to do.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: James Morris <jmorris@namei.org>
Right now the audit filter can match on = != > < >= blah blah blah.
This allow the filter to also look at bitwise AND operations, &
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The sanity check in audit_match_class() is wrong. We are able to audit
2048 syscalls but in audit_match_class() we were accidentally using
sizeof(_u32) instead of number of bits in _u32 when deciding how many
syscalls were valid. On ia64 in particular we were hitting syscall
numbers over the (wrong) limit of 256. Fixing the audit_match_class
check takes care of the problem.
Signed-off-by: Klaus Weidner <klaus@atsec.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The mode fields for IPC records are not consistent. Some are hex, others are
octal. This patch makes them all octal.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Otherwise smp_affinity would only update after the next interrupt
on x86 systems.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
i386 and sparc64 have the identical code to update the cmos clock. Move it
into kernel/time/ntp.c as there are other architectures coming along with the
same requirements.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
