hw_perf_enable() would enable already enabled events.
This causes problems with code that assumes that ->enable/->disable calls
are balanced (like the LBR code does).
What happens is that events that were already running and left in place
would get enabled again.
Avoid this by only enabling new events that match their previous
assignment.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hw_perf_enable() would disable events that were not yet enabled.
This causes problems with code that assumes that ->enable/->disable calls
are balanced (like the LBR code does).
What happens is that we disable newly added counters that match their
previous assignment, even though they are not yet programmed on the
hardware.
Avoid this by only doing the first pass over the existing events.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make sure n_added is properly accounted so that we can rely on the value
to reflect the number of added counters. This is needed if its going to
be used for more than a boolean check.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Calling ioctl(PERF_EVENT_IOC_DISABLE) on a thottled counter would result
in a double disable, cure this by using x86_pmu_{start,stop} for
throttle/unthrottle and teach x86_pmu_stop() to check ->active_mask.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There is no concurrency on these variables, so don't use LOCK'ed ops.
As to the intel_pmu_handle_irq() status bit clean, nobody uses that so
remove it all together.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100304140100.240023029@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Pass the full perf_event into the x86_pmu functions so that those may
make use of more than the hw_perf_event, and while doing this, remove the
superfluous second argument.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100304140100.165166129@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The second and third argument to x86_perf_event_update() are superfluous
since they are simple expressions of the first argument. Hence remove
them.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100304140100.089468871@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The second and third argument to x86_perf_event_set_period() are
superfluous since they are simple expressions of the first argument.
Hence remove them.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100304140100.006500906@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove the hw_perf_event_*() hotplug hooks in favour of per PMU hotplug
notifiers. This has the advantage of reducing the static weak interface
as well as exposing all hotplug actions to the PMU.
Use this to fix x86 hotplug usage where we did things in ONLINE which
should have been done in UP_PREPARE or STARTING.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100305154128.736225361@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This makes it easier to extend perf_sample_data and fixes a bug on arm
and sparc, which failed to set ->raw to NULL, which can cause crashes
when combined with PERF_SAMPLE_RAW.
It also optimizes PowerPC and tracepoint, because the struct
initialization is forced to zero out the whole structure.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Jean Pihet <jpihet@mvista.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Jamie Iles <jamie.iles@picochip.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: stable@kernel.org
LKML-Reference: <20100304140100.315416040@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (62 commits)
msi-laptop: depends on RFKILL
msi-laptop: Detect 3G device exists by standard ec command
msi-laptop: Add resume method for set the SCM load again
msi-laptop: Support some MSI 3G netbook that is need load SCM
msi-laptop: Add threeg sysfs file for support query 3G state by standard 66/62 ec command
msi-laptop: Support standard ec 66/62 command on MSI notebook and nebook
Driver core: create lock/unlock functions for struct device
sysfs: fix for thinko with sysfs_bin_attr_init()
sysfs: Kill unused sysfs_sb variable.
sysfs: Pass super_block to sysfs_get_inode
driver core: Use sysfs_rename_link in device_rename
sysfs: Implement sysfs_rename_link
sysfs: Pack sysfs_dirent more tightly.
sysfs: Serialize updates to the vfs inode
sysfs: windfarm: init sysfs attributes
sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on module dynamic attributes
sysfs: Document sysfs_attr_init and sysfs_bin_attr_init
sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on dynamic attributes
sysfs: Use one lockdep class per sysfs attribute.
sysfs: Only take active references on attributes.
...
Declare the smsgiucv prefix char pointer as "const" and use
use const char pointers in callback functions.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
zfcp and qeth are setting flags for the qdio-layer, but these flags
are not used in qdio. Patch removes the flag definitions from qdio
and their settings in zfcp and qeth.
Cc: Jan Glauber <jang@linux.vnet.ibm.com>
Cc: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This replaces direct xtime usage in the s390 arch with timekeeping accessors,
so we can further clean up the timekeeping core.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If there is no in kernel image caller modules will suffer:
ERROR: "copy_from_user_overflow" [net/core/pktgen.ko] undefined!
ERROR: "copy_from_user_overflow" [net/can/can-raw.ko] undefined!
ERROR: "copy_from_user_overflow" [fs/cifs/cifs.ko] undefined!
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
These are the non-static sysfs attributes that exist on
my test machine. Fix them to use sysfs_attr_init or
sysfs_bin_attr_init as appropriate. It simply requires
making a sysfs attribute present to see this. So this
is a little bit tedious but otherwise not too bad.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A pointer to a probe callback is passed to the core via
platform_driver_register and so the function must not disappear when the
.init sections are discarded. Otherwise (if also having HOTPLUG=y)
unbinding and binding a device to the driver via sysfs will result in an
oops as does a device being registered late.
An alternative to this patch is using platform_driver_probe instead of
platform_driver_register plus removing the pointer to the probe function
from the struct platform_driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Cc: Paul Sokolovsky <pmiscml@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Acked-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In linux-next "sysdev: Pass attribute in sysdev_class attributes show/store"
forgot to convert one place in s390 code. Here is the missing part.
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Passing the attribute to the low level IO functions allows all kinds
of cleanups, by sharing low level IO code without requiring
an own function for every piece of data.
Also drivers can extend the attributes with own data fields
and use that in the low level function.
Similar to sysdev_attributes and normal attributes.
This is a tree-wide sweep, converting everything in one go.
No functional changes in this patch other than passing the new
argument everywhere.
Tested on x86, the non x86 parts are uncompiled.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (26 commits)
sh: Convert sh to use read/update_persistent_clock
sh: Move PMB debugfs entry initialization to later stage
sh: Fix up flush_cache_vmap() on SMP.
sh: fix up MMU reset with variable PMB mapping sizes.
sh: establish PMB mappings for NUMA nodes.
sh: check for existing mappings for bolted PMB entries.
sh: fixed virt/phys mapping helpers for PMB.
sh: make pmb iomapping configurable.
sh: reworked dynamic PMB mapping.
sh: Fix up cpumask_of_pcibus() for the NUMA build.
serial: sh-sci: Tidy up build warnings.
sh: Fix up ctrl_read/write stragglers in migor setup.
serial: sh-sci: Add DMA support.
dmaengine: shdma: extend .device_terminate_all() to record partial transfer
sh: merge sh7722 and sh7724 DMA register definitions
sh: activate runtime PM for dmaengine on sh7722 and sh7724
dmaengine: shdma: add runtime PM support.
dmaengine: shdma: separate DMA headers.
dmaengine: shdma: convert to platform device resources
dmaengine: shdma: fix DMA error handling.
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6:
parisc: use __ratelimit in unaligned.c
parisc: Convert to read/update_persistent_clock
parisc: Simplify param.h by including <asm-generic/param.h>
parisc: drop unnecessary cast in __ldcw_align() macro
parisc: add strict copy size checks (v2)
parisc: remove trailing space in messages
parisc: ditto sys_accept4
parisc: wire up sys_recvmmsg
This patch converts the parisc architecture to use the generic
read_persistent_clock and update_persistent_clock interfaces, reducing
the amount of arch specific code we have to maintain, and allowing for
further cleanups in the future.
I have not built or tested this patch, so help from arch maintainers
would be appreciated.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
__ldcw_align() can directly access the slock member of struct arch_spinlock_t
instead of using an ugly cast.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Add CONFIG_DEBUG_STRICT_USER_COPY_CHECKS, copied from the x86
implementation. Tested with 32 and 64bit kernel.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
The current ELF dumper implementation can produce broken corefiles if
program headers exceed 65535. This number is determined by the number of
vmas which the process have. In particular, some extreme programs may use
more than 65535 vmas. (If you google max_map_count, you can find some
users facing this problem.) This kind of program never be able to generate
correct coredumps.
This patch implements ``extended numbering'' that uses sh_info field of
the first section header instead of e_phnum field in order to represent
upto 4294967295 vmas.
This is supported by
AMD64-ABI(http://www.x86-64.org/documentation.html) and
Solaris(http://docs.sun.com/app/docs/doc/817-1984/).
Of course, we are preparing patches for gdb and binutils.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
elf_core_dump() and elf_fdpic_core_dump() use #ifdef and the corresponding
macro for hiding _multiline_ logics in functions. This patch removes
#ifdef and replaces ELF_CORE_EXTRA_* by corresponding functions. For
architectures not implemeonting ELF_CORE_EXTRA_*, we use weak functions in
order to reduce a range of modification.
This cleanup is for my next patches, but I think this cleanup itself is
worth doing regardless of my firnal purpose.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The macro any_online_node() is prone to producing sparse warnings due to
the local symbol 'node'. Since all the in-tree users are really
requesting the first online node (the mask argument is either
NODE_MASK_ALL or node_online_map) just use the first_online_node macro and
remove the any_online_node macro since there are no users.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Milton Miller <miltonm@bga.com>
Cc: Nathan Fontenot <nfont@austin.ibm.com>
Cc: Geoff Levand <geoffrey.levand@am.sony.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Benny Halevy <bhalevy@panasas.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tell git to ignore the generated files under um, except:
include/shared/kern_constants.h
include/shared/user_constants.h
which will be moved to include/generated.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Assign tty only if line is not NULL.
[akpm@linux-foundation.org: simplification]
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With id 1 the wrong bp was unwatched.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
size_t desc_len cannot be less than 0, test before the subtraction.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert cris to use GENERIC_TIME via the arch_getoffset() infrastructure,
reducing the amount of arch specific code we need to maintain.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The initial -EINVAL value is overwritten by `retval = PTR_ERR(name)'. If
this isn't an error pointer and typenr is not 1, 6 or 9, then this retval,
a pointer cast to a long, is returned.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No architecture except for frv has pci_dma_sync_single() and
pci_dma_sync_sg(). The APIs are deprecated.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The old anon_vma code can lead to scalability issues with heavily forking
workloads. Specifically, each anon_vma will be shared between the parent
process and all its child processes.
In a workload with 1000 child processes and a VMA with 1000 anonymous
pages per process that get COWed, this leads to a system with a million
anonymous pages in the same anon_vma, each of which is mapped in just one
of the 1000 processes. However, the current rmap code needs to walk them
all, leading to O(N) scanning complexity for each page.
This can result in systems where one CPU is walking the page tables of
1000 processes in page_referenced_one, while all other CPUs are stuck on
the anon_vma lock. This leads to catastrophic failure for a benchmark
like AIM7, where the total number of processes can reach in the tens of
thousands. Real workloads are still a factor 10 less process intensive
than AIM7, but they are catching up.
This patch changes the way anon_vmas and VMAs are linked, which allows us
to associate multiple anon_vmas with a VMA. At fork time, each child
process gets its own anon_vmas, in which its COWed pages will be
instantiated. The parents' anon_vma is also linked to the VMA, because
non-COWed pages could be present in any of the children.
This reduces rmap scanning complexity to O(1) for the pages of the 1000
child processes, with O(N) complexity for at most 1/N pages in the system.
This reduces the average scanning cost in heavily forking workloads from
O(N) to 2.
The only real complexity in this patch stems from the fact that linking a
VMA to anon_vmas now involves memory allocations. This means vma_adjust
can fail, if it needs to attach a VMA to anon_vma structures. This in
turn means error handling needs to be added to the calling functions.
A second source of complexity is that, because there can be multiple
anon_vmas, the anon_vma linking in vma_adjust can no longer be done under
"the" anon_vma lock. To prevent the rmap code from walking up an
incomplete VMA, this patch introduces the VM_LOCK_RMAP VMA flag. This bit
flag uses the same slot as the NOMMU VM_MAPPED_COPY, with an ifdef in mm.h
to make sure it is impossible to compile a kernel that needs both symbolic
values for the same bitflag.
Some test results:
Without the anon_vma changes, when AIM7 hits around 9.7k users (on a test
box with 16GB RAM and not quite enough IO), the system ends up running
>99% in system time, with every CPU on the same anon_vma lock in the
pageout code.
With these changes, AIM7 hits the cross-over point around 29.7k users.
This happens with ~99% IO wait time, there never seems to be any spike in
system time. The anon_vma lock contention appears to be resolved.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename for_each_bit to for_each_set_bit in the kernel source tree. To
permit for_each_clear_bit(), should that ever be added.
The patch includes a macro to map the old for_each_bit() onto the new
for_each_set_bit(). This is a (very) temporary thing to ease the migration.
[akpm@linux-foundation.org: add temporary for_each_bit()]
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
