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12 years agomm,x86,um: move CMPXCHG_DOUBLE config option
Heiko Carstens [Fri, 16 Dec 2011 04:50:03 +0000 (15:50 +1100)]
mm,x86,um: move CMPXCHG_DOUBLE config option

Move CMPXCHG_DOUBLE and rename it to HAVE_CMPXCHG_DOUBLE so architectures
can simply select the option if it is supported.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm,x86,um: move CMPXCHG_LOCAL config option
Heiko Carstens [Fri, 16 Dec 2011 04:50:03 +0000 (15:50 +1100)]
mm,x86,um: move CMPXCHG_LOCAL config option

Move CMPXCHG_LOCAL and rename it to HAVE_CMPXCHG_LOCAL so architectures
can simply select the option if it is supported.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm,slub,x86: decouple size of struct page from CONFIG_CMPXCHG_LOCAL
Heiko Carstens [Fri, 16 Dec 2011 04:50:03 +0000 (15:50 +1100)]
mm,slub,x86: decouple size of struct page from CONFIG_CMPXCHG_LOCAL

While implementing cmpxchg_double() on s390 I realized that we don't set
CONFIG_CMPXCHG_LOCAL besides the fact that we have support for it.
However setting that option will increase the size of struct page by eight
bytes on 64 bit, which we certainly do not want.  Also, it doesn't make
sense that a present cpu feature should increase the size of struct page.

Besides that it looks like the dependency to CMPXCHG_LOCAL is wrong and
that it should depend on CMPXCHG_DOUBLE instead.

This patch:

If an architecture supports CMPXCHG_LOCAL this shouldn't result
automatically in larger struct pages if the SLUB allocator is used.
Instead introduce a new config option "HAVE_ALIGNED_STRUCT_PAGE" which can
be selected if a double word aligned struct page is required.  Also update
x86 Kconfig so that it should work as before.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoinclude/linux/linkage.h: remove unused ATTRIB_NORET macro
Joe Perches [Fri, 16 Dec 2011 04:50:02 +0000 (15:50 +1100)]
include/linux/linkage.h: remove unused ATTRIB_NORET macro

The uses have been renamed so delete the unused macro.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agotreewide-convert-uses-of-attrib_noreturn-to-__noreturn-checkpatch-fixes
Andrew Morton [Fri, 16 Dec 2011 04:50:02 +0000 (15:50 +1100)]
treewide-convert-uses-of-attrib_noreturn-to-__noreturn-checkpatch-fixes

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
WARNING: please, no spaces at the start of a line
#57: FILE: arch/m68k/amiga/config.c:515:
+    __noreturn;$

total: 0 errors, 1 warnings, 106 lines checked

./patches/treewide-convert-uses-of-attrib_noreturn-to-__noreturn.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agotreewide: convert uses of ATTRIB_NORETURN to __noreturn
Joe Perches [Fri, 16 Dec 2011 04:50:02 +0000 (15:50 +1100)]
treewide: convert uses of ATTRIB_NORETURN to __noreturn

Use the more commonly used __noreturn instead of ATTRIB_NORETURN.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agotreewide: remove useless NORET_TYPE macro and uses
Joe Perches [Fri, 16 Dec 2011 04:50:01 +0000 (15:50 +1100)]
treewide: remove useless NORET_TYPE macro and uses

It's a very old and now unused prototype marking so just delete it.

Neaten panic pointer argument style to keep checkpatch quiet.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoinclude/linux/linkage.h: remove unused NORET_AND macro
Joe Perches [Fri, 16 Dec 2011 04:50:00 +0000 (15:50 +1100)]
include/linux/linkage.h: remove unused NORET_AND macro

The only use in kernel.h is gone so remove the macro.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agokernel.h: neaten panic prototype
Joe Perches [Fri, 16 Dec 2011 04:50:00 +0000 (15:50 +1100)]
kernel.h: neaten panic prototype

Use __printf macro.
Convert NORET_AND to ATTRIB_NORET.
Use the normal kernel style for pointer arguments.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agointel_idle: disable auto_demotion for hotplugged CPUs
Shaohua Li [Fri, 16 Dec 2011 04:50:00 +0000 (15:50 +1100)]
intel_idle: disable auto_demotion for hotplugged CPUs

auto_demotion_disable is called only for online CPUs.  For hotplugged
CPUs, we should disable it too.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agointel_idle: fix API misuse
Shaohua Li [Fri, 16 Dec 2011 04:49:59 +0000 (15:49 +1100)]
intel_idle: fix API misuse

smp_call_function() only lets all other CPUs execute a specific function,
while we expect all CPUs do in intel_idle.  Without the fix, we could have
one cpu which has auto_demotion enabled or has no boradcast timer setup.
Usually we don't see impact because auto demotion just harms power and the
intel_idle init is called in CPU 0, where boradcast timer delivers
interrupt, but this still could be a problem.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agohpet: factor timer allocate from open
Magnus Lynch [Fri, 16 Dec 2011 04:49:59 +0000 (15:49 +1100)]
hpet: factor timer allocate from open

The current implementation of the /dev/hpet driver couples opening the
device with allocating one of the (scarce) timers (aka comparators).  This
is a limitation in that the main counter may be valuable to applications
seeking a high-resolution timer who have no use for the interrupt
generating functionality of the comparators.

This patch alters the open semantics so that when the device is opened, no
timer is allocated.  Operations that depend on a timer being in context
implicitly attempt allocating a timer, to maintain backward compatibility.
 There is also an IOCTL (HPET_ALLOC_TIMER _IO) added so that the
allocation may be done explicitly.  (I prefer the explicit open then
allocate pattern but don't know how practical it would be to require all
existing code to be changed.)

/dev/hpet is accessed via mmap().  This is the only interface of /dev/hpet
that is actually used in practice.

[akpm@linux-foundation.org: coding-style tweaks]
[arnd@arndb.de: fix build]
Signed-off-by: Magnus Lynch <maglyx@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agotracepoint: add tracepoints for debugging oom_score_adj
KAMEZAWA Hiroyuki [Fri, 16 Dec 2011 04:49:58 +0000 (15:49 +1100)]
tracepoint: add tracepoints for debugging oom_score_adj

oom_score_adj is used for guarding processes from OOM-Killer.  One of
problem is that it's inherited at fork().  When a daemon set oom_score_adj
and make children, it's hard to know where the value is set.

This patch adds some tracepoints useful for debugging. This patch adds
3 trace points.
  - creating new task
  - renaming a task (exec)
  - set oom_score_adj

To debug, users need to enable some trace pointer. Maybe filtering is useful as

# EVENT=/sys/kernel/debug/tracing/events/task/
# echo "oom_score_adj != 0" > $EVENT/task_newtask/filter
# echo "oom_score_adj != 0" > $EVENT/task_rename/filter
# echo 1 > $EVENT/enable
# EVENT=/sys/kernel/debug/tracing/events/oom/
# echo 1 > $EVENT/enable

output will be like this.
# grep oom /sys/kernel/debug/tracing/trace
bash-7699  [007] d..3  5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000
bash-7699  [007] ...1  5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000
ls-7729  [003] ...2  5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000
bash-7699  [002] ...1  5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000
grep-7730  [007] ...2  5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: simplify find_vma_prev
KOSAKI Motohiro [Fri, 16 Dec 2011 04:49:58 +0000 (15:49 +1100)]
mm: simplify find_vma_prev

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-simplify-find_vma_prev-fix
Andrew Morton [Fri, 16 Dec 2011 04:49:58 +0000 (15:49 +1100)]
mm-simplify-find_vma_prev-fix

Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: simplify find_vma_prev()
KOSAKI Motohiro [Fri, 16 Dec 2011 04:49:57 +0000 (15:49 +1100)]
mm: simplify find_vma_prev()

commit 297c5eee37 ("mm: make the vma list be doubly linked") added the
vm_prev member to vm_area_struct.  We can simplify find_vma_prev() by
using it.  Also, this change helps to improve page fault performance
because it has stronger locality of reference.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomremap-enforce-rmap-src-dst-vma-ordering-in-case-of-vma_merge-succeeding-in-copy_vma...
Andrea Arcangeli [Fri, 16 Dec 2011 04:49:57 +0000 (15:49 +1100)]
mremap-enforce-rmap-src-dst-vma-ordering-in-case-of-vma_merge-succeeding-in-copy_vma-update

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pawel Sikora <pluto@agmk.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomremap: enforce rmap src/dst vma ordering in case of vma_merge() succeeding in copy_vma()
Andrea Arcangeli [Fri, 16 Dec 2011 04:49:57 +0000 (15:49 +1100)]
mremap: enforce rmap src/dst vma ordering in case of vma_merge() succeeding in copy_vma()

migrate was doing an rmap_walk with speculative lock-less access on
pagetables.  That could lead it to not serializing properly against mremap
PT locks.  But a second problem remains in the order of vmas in the
same_anon_vma list used by the rmap_walk.

If vma_merge succeeds in copy_vma, the src vma could be placed after the
dst vma in the same_anon_vma list.  That could still lead to migrate
missing some pte.

This patch adds an anon_vma_moveto_tail() function to force the dst vma at
the end of the list before mremap starts to solve the problem.

If the mremap is very large and there are a lots of parents or childs
sharing the anon_vma root lock, this should still scale better than taking
the anon_vma root lock around every pte copy practically for the whole
duration of mremap.

Update: Hugh noticed special care is needed in the error path where
move_page_tables goes in the reverse direction, a second
anon_vma_moveto_tail() call is needed in the error path.

This program exercises the anon_vma_moveto_tail:

===

int main()
{
static struct timeval oldstamp, newstamp;
long diffsec;
char *p, *p2, *p3, *p4;
if (posix_memalign((void **)&p, 2*1024*1024, SIZE))
perror("memalign"), exit(1);
if (posix_memalign((void **)&p2, 2*1024*1024, SIZE))
perror("memalign"), exit(1);
if (posix_memalign((void **)&p3, 2*1024*1024, SIZE))
perror("memalign"), exit(1);

memset(p, 0xff, SIZE);
printf("%p\n", p);
memset(p2, 0xff, SIZE);
memset(p3, 0x77, 4096);
if (memcmp(p, p2, SIZE))
printf("error\n");
p4 = mremap(p+SIZE/2, SIZE/2, SIZE/2, MREMAP_FIXED|MREMAP_MAYMOVE, p3);
if (p4 != p3)
perror("mremap"), exit(1);
p4 = mremap(p4, SIZE/2, SIZE/2, MREMAP_FIXED|MREMAP_MAYMOVE, p+SIZE/2);
if (p4 != p+SIZE/2)
perror("mremap"), exit(1);
if (memcmp(p, p2, SIZE))
printf("error\n");
printf("ok\n");

return 0;
}
===

$ perf probe -a anon_vma_moveto_tail
Add new event:
  probe:anon_vma_moveto_tail (on anon_vma_moveto_tail)

You can now use it on all perf tools, such as:

        perf record -e probe:anon_vma_moveto_tail -aR sleep 1

$ perf record -e probe:anon_vma_moveto_tail -aR ./anon_vma_moveto_tail
0x7f2ca2800000
ok
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.043 MB perf.data (~1860 samples) ]
$ perf report --stdio
   100.00%  anon_vma_moveto  [kernel.kallsyms]  [k] anon_vma_moveto_tail

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Nai Xia <nai.xia@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pawel Sikora <pluto@agmk.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: fix off-by-two in __zone_watermark_ok()
Michal Hocko [Fri, 16 Dec 2011 04:49:56 +0000 (15:49 +1100)]
mm: fix off-by-two in __zone_watermark_ok()

88f5acf8 ("mm: page allocator: adjust the per-cpu counter threshold when
memory is low") changed the form how free_pages is calculated but it
forgot that we used to do free_pages - ((1 << order) - 1) so we ended up
with off-by-two when calculating free_pages.

Reported-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agobootmem: micro optimize freeing pages in bulk
Uwe Kleine-König [Fri, 16 Dec 2011 04:49:56 +0000 (15:49 +1100)]
bootmem: micro optimize freeing pages in bulk

The first entry of bdata->node_bootmem_map holds the data for
bdata->node_min_pfn up to bdata->node_min_pfn + BITS_PER_LONG - 1.  So the
test for freeing all pages of a single map entry can be slightly relaxed.

Moreover use DIV_ROUND_UP in another place instead of open coding it.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: compaction: push isolate search base of compact control one pfn ahead
Hillf Danton [Fri, 16 Dec 2011 04:49:56 +0000 (15:49 +1100)]
mm: compaction: push isolate search base of compact control one pfn ahead

After isolated the current pfn will no longer be scanned and isolated if
the next round is necessary, so push the isolate_migratepages search base
of the given compact_control one step ahead.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoBtrfs: pass __GFP_WRITE for buffered write page allocations
Johannes Weiner [Fri, 16 Dec 2011 04:49:55 +0000 (15:49 +1100)]
Btrfs: pass __GFP_WRITE for buffered write page allocations

Tell the page allocator that pages allocated for a buffered write are
expected to become dirty soon.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: filemap: pass __GFP_WRITE from grab_cache_page_write_begin()
Johannes Weiner [Fri, 16 Dec 2011 04:49:55 +0000 (15:49 +1100)]
mm: filemap: pass __GFP_WRITE from grab_cache_page_write_begin()

Tell the page allocator that pages allocated through
grab_cache_page_write_begin() are expected to become dirty soon.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: try to distribute dirty pages fairly across zones
Johannes Weiner [Fri, 16 Dec 2011 04:49:55 +0000 (15:49 +1100)]
mm: try to distribute dirty pages fairly across zones

The maximum number of dirty pages that exist in the system at any time is
determined by a number of pages considered dirtyable and a user-configured
percentage of those, or an absolute number in bytes.

This number of dirtyable pages is the sum of memory provided by all the
zones in the system minus their lowmem reserves and high watermarks, so
that the system can retain a healthy number of free pages without having
to reclaim dirty pages.

But there is a flaw in that we have a zoned page allocator which does not
care about the global state but rather the state of individual memory
zones.  And right now there is nothing that prevents one zone from filling
up with dirty pages while other zones are spared, which frequently leads
to situations where kswapd, in order to restore the watermark of free
pages, does indeed have to write pages from that zone's LRU list.  This
can interfere so badly with IO from the flusher threads that major
filesystems (btrfs, xfs, ext4) mostly ignore write requests from reclaim
already, taking away the VM's only possibility to keep such a zone
balanced, aside from hoping the flushers will soon clean pages from that
zone.

Enter per-zone dirty limits.  They are to a zone's dirtyable memory what
the global limit is to the global amount of dirtyable memory, and try to
make sure that no single zone receives more than its fair share of the
globally allowed dirty pages in the first place.  As the number of pages
considered dirtyable excludes the zones' lowmem reserves and high
watermarks, the maximum number of dirty pages in a zone is such that the
zone can always be balanced without requiring page cleaning.

As this is a placement decision in the page allocator and pages are
dirtied only after the allocation, this patch allows allocators to pass
__GFP_WRITE when they know in advance that the page will be written to and
become dirty soon.  The page allocator will then attempt to allocate from
the first zone of the zonelist - which on NUMA is determined by the task's
NUMA memory policy - that has not exceeded its dirty limit.

At first glance, it would appear that the diversion to lower zones can
increase pressure on them, but this is not the case.  With a full high
zone, allocations will be diverted to lower zones eventually, so it is
more of a shift in timing of the lower zone allocations.  Workloads that
previously could fit their dirty pages completely in the higher zone may
be forced to allocate from lower zones, but the amount of pages that
"spill over" are limited themselves by the lower zones' dirty constraints,
and thus unlikely to become a problem.

For now, the problem of unfair dirty page distribution remains for NUMA
configurations where the zones allowed for allocation are in sum not big
enough to trigger the global dirty limits, wake up the flusher threads and
remedy the situation.  Because of this, an allocation that could not
succeed on any of the considered zones is allowed to ignore the dirty
limits before going into direct reclaim or even failing the allocation,
until a future patch changes the global dirty throttling and flusher
thread activation so that they take individual zone states into account.

Test results

15M DMA + 3246M DMA32 + 504 Normal = 3765M memory
40% dirty ratio
16G USB thumb drive
10 runs of dd if=/dev/zero of=disk/zeroes bs=32k count=$((10 << 15))

seconds nr_vmscan_write
        (stddev)        min|     median|        max
xfs
vanilla:  549.747( 3.492)      0.000|      0.000|      0.000
patched:  550.996( 3.802)      0.000|      0.000|      0.000

fuse-ntfs
vanilla: 1183.094(53.178)  54349.000|  59341.000|  65163.000
patched:  558.049(17.914)      0.000|      0.000|     43.000

btrfs
vanilla:  573.679(14.015) 156657.000| 460178.000| 606926.000
patched:  563.365(11.368)      0.000|      0.000|   1362.000

ext4
vanilla:  561.197(15.782)      0.000|2725438.000|4143837.000
patched:  568.806(17.496)      0.000|      0.000|      0.000

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: writeback: cleanups in preparation for per-zone dirty limits
Johannes Weiner [Fri, 16 Dec 2011 04:49:54 +0000 (15:49 +1100)]
mm: writeback: cleanups in preparation for per-zone dirty limits

The next patch will introduce per-zone dirty limiting functions in
addition to the traditional global dirty limiting.

Rename determine_dirtyable_memory() to global_dirtyable_memory() before
adding the zone-specific version, and fix up its documentation.

Also, move the functions to determine the dirtyable memory and the
function to calculate the dirty limit based on that together so that their
relationship is more apparent and that they can be commented on as a
group.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mel@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-exclude-reserved-pages-from-dirtyable-memory-fix
Andrew Morton [Fri, 16 Dec 2011 04:49:54 +0000 (15:49 +1100)]
mm-exclude-reserved-pages-from-dirtyable-memory-fix

fix highmem build

Cc: Chris Mason <chris.mason@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: exclude reserved pages from dirtyable memory
Johannes Weiner [Fri, 16 Dec 2011 04:49:54 +0000 (15:49 +1100)]
mm: exclude reserved pages from dirtyable memory

Per-zone dirty limits try to distribute page cache pages allocated for
writing across zones in proportion to the individual zone sizes, to reduce
the likelihood of reclaim having to write back individual pages from the
LRU lists in order to make progress.

This patch:

The amount of dirtyable pages should not include the full number of free
pages: there is a number of reserved pages that the page allocator and
kswapd always try to keep free.

The closer (reclaimable pages - dirty pages) is to the number of reserved
pages, the more likely it becomes for reclaim to run into dirty pages:

       +----------+ ---
       |   anon   |  |
       +----------+  |
       |          |  |
       |          |  -- dirty limit new    -- flusher new
       |   file   |  |                     |
       |          |  |                     |
       |          |  -- dirty limit old    -- flusher old
       |          |                        |
       +----------+                       --- reclaim
       | reserved |
       +----------+
       |  kernel  |
       +----------+

This patch introduces a per-zone dirty reserve that takes both the lowmem
reserve as well as the high watermark of the zone into account, and a
global sum of those per-zone values that is subtracted from the global
amount of dirtyable pages.  The lowmem reserve is unavailable to page
cache allocations and kswapd tries to keep the high watermark free.  We
don't want to end up in a situation where reclaim has to clean pages in
order to balance zones.

Not treating reserved pages as dirtyable on a global level is only a
conceptual fix.  In reality, dirty pages are not distributed equally
across zones and reclaim runs into dirty pages on a regular basis.

But it is important to get this right before tackling the problem on a
per-zone level, where the distance between reclaim and the dirty pages is
mostly much smaller in absolute numbers.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agovmscan: add task name to warn_scan_unevictable() messages
KOSAKI Motohiro [Fri, 16 Dec 2011 04:49:53 +0000 (15:49 +1100)]
vmscan: add task name to warn_scan_unevictable() messages

If we need to know a usecase, caller program name is critical important.
Show it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
David Rientjes <rientjes@google.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm, debug: test for online nid when allocating on single node
David Rientjes [Fri, 16 Dec 2011 04:49:53 +0000 (15:49 +1100)]
mm, debug: test for online nid when allocating on single node

Calling alloc_pages_exact_node() means the allocation only passes the
zonelist of a single node into the page allocator.  If that node isn't
online, it's zonelist may never have been initialized causing a strange
oops that may not immediately be clear.

I recently debugged an issue where node 0 wasn't online and an allocator
was passing 0 to alloc_pages_exact_node() and it resulted in a NULL
pointer on zonelist->_zoneref.  If CONFIG_DEBUG_VM is enabled, though, it
would be nice to catch this a bit earlier.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agofadvise: only initiate writeback for specified range with FADV_DONTNEED
Shawn Bohrer [Fri, 16 Dec 2011 04:49:52 +0000 (15:49 +1100)]
fadvise: only initiate writeback for specified range with FADV_DONTNEED

Previously POSIX_FADV_DONTNEED would start writeback for the entire file
when the bdi was not write congested.  This negatively impacts performance
if the file contians dirty pages outside of the requested range.  This
change uses __filemap_fdatawrite_range() to only initiate writeback for
the requested range.

Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoslub: min order when debug_guardpage_minorder > 0
Stanislaw Gruszka [Fri, 16 Dec 2011 04:49:52 +0000 (15:49 +1100)]
slub: min order when debug_guardpage_minorder > 0

Disable slub debug facilities and allocate slabs at minimal order when
debug_guardpage_minorder > 0 to increase probability to catch random
memory corruption by cpu exception.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoPM/Hibernate: do not count debug pages as savable
Stanislaw Gruszka [Fri, 16 Dec 2011 04:49:52 +0000 (15:49 +1100)]
PM/Hibernate: do not count debug pages as savable

When debugging with CONFIG_DEBUG_PAGEALLOC and debug_guardpage_minorder >
0, we have lot of free pages that are not marked so.  Snapshot code
account them as savable, what cause hibernate memory preallocation
failure.

It is pretty hard to make hibernate allocation succeed with
debug_guardpage_minorder=1.  This change at least make it possible when
system has relatively big amount of RAM.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-more-intensive-memory-corruption-debug-fix
Andrew Morton [Fri, 16 Dec 2011 04:49:51 +0000 (15:49 +1100)]
mm-more-intensive-memory-corruption-debug-fix

tweak documentation, s/flg/flag/

Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: more intensive memory corruption debugging
Stanislaw Gruszka [Fri, 16 Dec 2011 04:49:51 +0000 (15:49 +1100)]
mm: more intensive memory corruption debugging

With CONFIG_DEBUG_PAGEALLOC configured, the CPU will generate an exception
on access (read,write) to an unallocated page, which permits us to catch
code which corrupts memory.  However the kernel is trying to maximise
memory usage, hence there are usually few free pages in the system and
buggy code usually corrupts some crucial data.

This patch changes the buddy allocator to keep more free/protected pages
and to interlace free/protected and allocated pages to increase the
probability of catching corruption.

When the kernel is compiled with CONFIG_DEBUG_PAGEALLOC,
debug_guardpage_minorder defines the minimum order used by the page
allocator to grant a request.  The requested size will be returned with
the remaining pages used as guard pages.

The default value of debug_guardpage_minorder is zero: no change from
current behaviour.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agohugetlb: replace BUG() with BUILD_BUG() for dummy definitions
David Daney [Fri, 16 Dec 2011 04:49:51 +0000 (15:49 +1100)]
hugetlb: replace BUG() with BUILD_BUG() for dummy definitions

The file linux/hugetlb.h has many places where dummy symbols were defined
so that the main source code would contain fewer:

    #ifdef CONFIG_HUGETLBFS

or

    #ifdef CONFIG_TRANSPARENT_HUGEPAGE

If there were any misuse of these symbols, the only symptom would be an
OOPS at runtime.  Change the BUG() to BUILD_BUG() to catch any such abuse
at compile time instead.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: David Rientjes <rientjes@google.com>
Cc: DM <dm.n9107@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agokernel.h: Add BUILD_BUG() macro.
David Daney [Fri, 16 Dec 2011 04:49:50 +0000 (15:49 +1100)]
kernel.h: Add BUILD_BUG() macro.

We can place this in definitions that we expect the compiler to remove
by dead code elimination.  If this assertion fails, we get a nice
error message at build time.

The GCC function attribute error("message") was added in version 4.3,
so we define a new macro __linktime_error(message) to expand to this
for GCC-4.3 and later.  This will give us an error diagnostic from the
compiler on the line that fails.  For other compilers
__linktime_error(message) expands to nothing, and we have to be
content with a link time error, but at least we will still get a build
error.

BUILD_BUG() expands to the undefined function __build_bug_failed() and
will fail at link time if the compiler ever emits code for it.  On
GCC-4.3 and later, attribute((error())) is used so that the failure
will be noted at compile time instead.

Acked-by: David Howells <dhowells@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: David Rientjes <rientjes@google.com>
Cc: DM <dm.n9107@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agokernel.h: add BUILD_BUG() macro
David Daney [Fri, 16 Dec 2011 04:49:50 +0000 (15:49 +1100)]
kernel.h: add BUILD_BUG() macro

We can place this in definitions that we expect the compiler to remove by
dead code elimination.  If this assertion fails, we get a nice error
message at build time.

The GCC function attribute error("message") was added in version 4.3, so
we define a new macro __linktime_error(message) to expand to this for
GCC-4.3 and later.  This will give us an error diagnostic from the
compiler on the line that fails.  For other compilers
__linktime_error(message) expands to nothing, and we have to be content
with a link time error, but at least we will still get a build error.

BUILD_BUG() expands to the undefined function __build_bug_failed() and
will fail at link time if the compiler ever emits code for it.  On GCC-4.3
and later, attribute((error())) is used so that the failure will be noted
at compile time instead.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: DM <dm.n9107@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-hugetlbc-fix-virtual-address-handling-in-hugetlb-fault-fix
Andrew Morton [Fri, 16 Dec 2011 04:49:50 +0000 (15:49 +1100)]
mm-hugetlbc-fix-virtual-address-handling-in-hugetlb-fault-fix

use &=

Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm/hugetlb.c: fix virtual address handling in hugetlb fault
KAMEZAWA Hiroyuki [Fri, 16 Dec 2011 04:49:49 +0000 (15:49 +1100)]
mm/hugetlb.c: fix virtual address handling in hugetlb fault

handle_mm_fault() passes 'faulted' address to hugetlb_fault().  This
address is not aligned to a hugepage boundary.

Most of the functions for hugetlb pages are aware of that and calculate an
alignment themselves.  However some functions such as
copy_user_huge_page() and clear_huge_page() don't handle alignment by
themselves.

This patch make hugeltb_fault() fix the alignment and pass an aligned
addresss (to address of a faulted hugepage) to functions.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agohugetlb: clarify hugetlb_instantiation_mutex usage
Michal Hocko [Fri, 16 Dec 2011 04:49:49 +0000 (15:49 +1100)]
hugetlb: clarify hugetlb_instantiation_mutex usage

Let's make it clear that we cannot race with other fault handlers due to
hugetlb (global) mutex.  Also make it clear that we want to keep pte_same
checks anayway to have a transition from the global mutex easier.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agohugetlb: detect race upon page allocation failure during COW
Hillf Danton [Fri, 16 Dec 2011 04:49:49 +0000 (15:49 +1100)]
hugetlb: detect race upon page allocation failure during COW

Currently we are not rechecking pte_same in hugetlb_cow after we take ptl
lock again in the page allocation failure code path and simply retry
again.  This is not an issue at the moment because hugetlb fault path is
protected by hugetlb_instantiation_mutex so we cannot race.

The original page is locked and so we cannot race even with the page
migration.

Let's add the pte_same check anyway as we want to be consistent with the
other check later in this function and be safe if we ever remove the
mutex.

[mhocko@suse.cz: reworded the changelog]
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: account reaped page cache on inode cache pruning
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:48 +0000 (15:49 +1100)]
mm: account reaped page cache on inode cache pruning

Inode cache pruning indirectly reclaims page-cache by invalidating mapping
pages.  Let's account them into reclaim-state to notice this progress in
memory reclaimer.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: avoid livelock on !__GFP_FS allocations
Mel Gorman [Fri, 16 Dec 2011 04:49:48 +0000 (15:49 +1100)]
mm: avoid livelock on !__GFP_FS allocations

Colin Cross reported;

  Under the following conditions, __alloc_pages_slowpath can loop forever:
  gfp_mask & __GFP_WAIT is true
  gfp_mask & __GFP_FS is false
  reclaim and compaction make no progress
  order <= PAGE_ALLOC_COSTLY_ORDER

  These conditions happen very often during suspend and resume,
  when pm_restrict_gfp_mask() effectively converts all GFP_KERNEL
  allocations into __GFP_WAIT.

  The oom killer is not run because gfp_mask & __GFP_FS is false,
  but should_alloc_retry will always return true when order is less
  than PAGE_ALLOC_COSTLY_ORDER.

In his fix, he avoided retrying the allocation if reclaim made no progress
and __GFP_FS was not set.  The problem is that this would result in
GFP_NOIO allocations failing that previously succeeded which would be very
unfortunate.

The big difference between GFP_NOIO and suspend converting GFP_KERNEL to
behave like GFP_NOIO is that normally flushers will be cleaning pages and
kswapd reclaims pages allowing GFP_NOIO to succeed after a short delay.
The same does not necessarily apply during suspend as the storage device
may be suspended.

This patch special cases the suspend case to fail the page allocation if
reclaim cannot make progress and adds some documentation on how
gfp_allowed_mask is currently used.  Failing allocations like this may
cause suspend to abort but that is better than a livelock.

[mgorman@suse.de: Rework fix to be suspend specific]
[rientjes@google.com: Move suspended device check to should_alloc_retry]
Reported-by: Colin Cross <ccross@android.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-reduce-the-amount-of-work-done-when-updating-min_free_kbytes-checkpatch-fixes
Andrew Morton [Fri, 16 Dec 2011 04:49:47 +0000 (15:49 +1100)]
mm-reduce-the-amount-of-work-done-when-updating-min_free_kbytes-checkpatch-fixes

Cc: Mel Gorman <mgorman@suse.de>
WARNING: line over 80 characters
#42: FILE: mm/page_alloc.c:3464:
+ /* Blocks with reserved pages will never free, skip them. */

WARNING: line over 80 characters
#61: FILE: mm/page_alloc.c:3477:
+ set_pageblock_migratetype(page, MIGRATE_RESERVE);

WARNING: line over 80 characters
#62: FILE: mm/page_alloc.c:3478:
+ move_freepages_block(zone, page, MIGRATE_RESERVE);

total: 0 errors, 3 warnings, 44 lines checked

./patches/mm-reduce-the-amount-of-work-done-when-updating-min_free_kbytes.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: reduce the amount of work done when updating min_free_kbytes
Mel Gorman [Fri, 16 Dec 2011 04:49:47 +0000 (15:49 +1100)]
mm: reduce the amount of work done when updating min_free_kbytes

When min_free_kbytes is updated, some pageblocks are marked
MIGRATE_RESERVE.  Ordinarily, this work is unnoticable as it happens early
in boot but on large machines with 1TB of memory, this has been reported
to delay boot times, probably due to the NUMA distances involved.

The bulk of the work is due to calling calling pageblock_is_reserved() an
unnecessary amount of times and accessing far more struct page metadata
than is necessary.  This patch significantly reduces the amount of work
done by setup_zone_migrate_reserve() improving boot times on 1TB machines.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-do-not-stall-in-synchronous-compaction-for-thp-allocations-v3
Mel Gorman [Fri, 16 Dec 2011 04:49:47 +0000 (15:49 +1100)]
mm-do-not-stall-in-synchronous-compaction-for-thp-allocations-v3

Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: do not stall in synchronous compaction for THP allocations
Mel Gorman [Fri, 16 Dec 2011 04:49:46 +0000 (15:49 +1100)]
mm: do not stall in synchronous compaction for THP allocations

Occasionally during large file copies to slow storage, there are still
reports of user-visible stalls when THP is enabled.  Reports on this have
been intermittent and not reliable to reproduce locally but;

Andy Isaacson reported a problem copying to VFAT on SD Card
https://lkml.org/lkml/2011/11/7/2

In this case, it was stuck in munmap for betwen 20 and 60
seconds in compaction. It is also possible that khugepaged
was holding mmap_sem on this process if CONFIG_NUMA was set.

Johannes Weiner reported stalls on USB
https://lkml.org/lkml/2011/7/25/378

In this case, there is no stack trace but it looks like the
same problem. The USB stick may have been using NTFS as a
filesystem based on other work done related to writing back
to USB around the same time.

Internally in SUSE, I received a bug report related to stalls in firefox
when using Java and Flash heavily while copying from NFS
to VFAT on USB. It has not been confirmed to be the same problem
but if it looks like a duck and quacks like a duck.....

In the past, commit [11bc82d6: mm: compaction: Use async migration for
__GFP_NO_KSWAPD and enforce no writeback] forced that sync compaction
would never be used for THP allocations.  This was reverted in commit
[c6a140bf: mm/compaction: reverse the change that forbade sync migraton
with __GFP_NO_KSWAPD] on the grounds that it was uncertain it was
beneficial.

While user-visible stalls do not happen for me when writing to USB, I
setup a test running postmark while short-lived processes created
anonymous mapping.  The objective was to exercise the paths that allocate
transparent huge pages.  I then logged when processes were stalled for
more than 1 second, recorded a stack strace and did some analysis to
aggregate unique "stall events" which revealed

Time stalled in this event:    47369 ms
Event count:                      20
usemem               sleep_on_page          3690 ms
usemem               sleep_on_page          2148 ms
usemem               sleep_on_page          1534 ms
usemem               sleep_on_page          1518 ms
usemem               sleep_on_page          1225 ms
usemem               sleep_on_page          2205 ms
usemem               sleep_on_page          2399 ms
usemem               sleep_on_page          2398 ms
usemem               sleep_on_page          3760 ms
usemem               sleep_on_page          1861 ms
usemem               sleep_on_page          2948 ms
usemem               sleep_on_page          1515 ms
usemem               sleep_on_page          1386 ms
usemem               sleep_on_page          1882 ms
usemem               sleep_on_page          1850 ms
usemem               sleep_on_page          3715 ms
usemem               sleep_on_page          3716 ms
usemem               sleep_on_page          4846 ms
usemem               sleep_on_page          1306 ms
usemem               sleep_on_page          1467 ms
[<ffffffff810ef30c>] wait_on_page_bit+0x6c/0x80
[<ffffffff8113de9f>] unmap_and_move+0x1bf/0x360
[<ffffffff8113e0e2>] migrate_pages+0xa2/0x1b0
[<ffffffff81134273>] compact_zone+0x1f3/0x2f0
[<ffffffff811345d8>] compact_zone_order+0xa8/0xf0
[<ffffffff811346ff>] try_to_compact_pages+0xdf/0x110
[<ffffffff810f773a>] __alloc_pages_direct_compact+0xda/0x1a0
[<ffffffff810f7d5d>] __alloc_pages_slowpath+0x55d/0x7a0
[<ffffffff810f8151>] __alloc_pages_nodemask+0x1b1/0x1c0
[<ffffffff811331db>] alloc_pages_vma+0x9b/0x160
[<ffffffff81142bb0>] do_huge_pmd_anonymous_page+0x160/0x270
[<ffffffff814410a7>] do_page_fault+0x207/0x4c0
[<ffffffff8143dde5>] page_fault+0x25/0x30

The stall times are approximate at best but the estimates represent 25% of
the worst stalls and even if the estimates are off by a factor of 10, it's
severe.

This patch once again prevents sync migration for transparent hugepage
allocations as it is preferable to fail a THP allocation than stall.

It was suggested that __GFP_NORETRY be used instead of __GFP_NO_KSWAPD to
look less like a special case.  This would prevent THP allocation using
sync compaction but it would have other side-effects.  There are existing
users of __GFP_NORETRY that are doing high-order allocations and while
they can handle allocation failure, it seems reasonable that they continue
to use sync compaction unless there is a deliberate reason to change that.
 To help clarify this for the future, this patch updates the comment for
__GFP_NO_KSWAPD.

If accepted, this is a -stable candidate.

Reported-by: Andy Isaacson <adi@hexapodia.org>
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@vger.kernel.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: migrate: one less atomic operation
Jacobo Giralt [Fri, 16 Dec 2011 04:49:46 +0000 (15:49 +1100)]
mm: migrate: one less atomic operation

migrate_page_move_mapping() drops a reference from the old page after
unfreezing its counter.  Both operations can be merged into a single
atomic operation by directly unfreezing to one less reference.

The same applies to migrate_huge_page_move_mapping().

Signed-off-by: Jacobo Giralt <jacobo.giralt@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-add-extra-free-kbytes-tunable-update-checkpatch-fixes
Andrew Morton [Fri, 16 Dec 2011 04:49:46 +0000 (15:49 +1100)]
mm-add-extra-free-kbytes-tunable-update-checkpatch-fixes

ERROR: trailing whitespace
#98: FILE: mm/page_alloc.c:5303:
+ * free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so $

ERROR: trailing whitespace
#103: FILE: mm/page_alloc.c:5307:
+int free_kbytes_sysctl_handler(ctl_table *table, int write, $

ERROR: need consistent spacing around '*' (ctx:WxV)
#103: FILE: mm/page_alloc.c:5307:
+int free_kbytes_sysctl_handler(ctl_table *table, int write,
                                          ^

total: 3 errors, 0 warnings, 69 lines checked

NOTE: whitespace errors detected, you may wish to use scripts/cleanpatch or
      scripts/cleanfile

./patches/mm-add-extra-free-kbytes-tunable-update.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-add-extra-free-kbytes-tunable-update
Rik van Riel [Fri, 16 Dec 2011 04:49:45 +0000 (15:49 +1100)]
mm-add-extra-free-kbytes-tunable-update

All the fixes suggested by Andrew Morton.   Not much of a changelog
since the patch should probably be folded into
mm-add-extra-free-kbytes-tunable.patch

Thank you for pointing these out, Andrew.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: add extra free kbytes tunable
Rik van Riel [Fri, 16 Dec 2011 04:49:45 +0000 (15:49 +1100)]
mm: add extra free kbytes tunable

Add a userspace visible knob to tell the VM to keep an extra amount of
memory free, by increasing the gap between each zone's min and low
watermarks.

This is useful for realtime applications that call system calls and have a
bound on the number of allocations that happen in any short time period.
In this application, extra_free_kbytes would be left at an amount equal to
or larger than than the maximum number of allocations that happen in any
burst.

It may also be useful to reduce the memory use of virtual machines
(temporarily?), in a way that does not cause memory fragmentation like
ballooning does.

Testing results from Satoru Moriya:

: I ran some sample workloads and measure memory allocation latency
: (latency of __alloc_page_nodemask()).
: The test is like following:
:
:  - CPU: 1 socket, 4 core
:  - Memory: 4GB
:
:  - Background load:
:    $ dd if=3D/dev/zero of=3D/tmp/tmp1
:    $ dd if=3D/dev/zero of=3D/tmp/tmp2
:    $ dd if=3D/dev/zero of=3D/tmp/tmp3
:
:  - Main load:
:    $ mapped-file-stream 1 $((1024 * 1024 * 640))  --(*)
:
:  (*) This is made by Johannes Weiner
:      https://lkml.org/lkml/2010/8/30/226
:
:      It allocates/access 640MByte memory at a burst.
:
: The result is follwoing:
:
:                                |         |  extra   |
:                                | default |  kbytes  |
: --------------------------------------------------------------
: min_free_kbytes                |    8113 |   8113   |
: extra_free_kbytes              |       0 | 640*1024 | (KB)
: --------------------------------------------------------------
: worst latency                  | 517.762 |  20.775  | (usec)
: --------------------------------------------------------------
: vmstat result                  |         |          |
:  nr_vmscan_write               |       0 |      0   |
:  pgsteal_dma                   |       0 |      0   |
:  pgsteal_dma32                 |  143667 | 144882   |
:  pgsteal_normal                |   31486 |  27001   |
:  pgsteal_movable               |       0 |      0   |
:  pgscan_kswapd_dma             |       0 |      0   |
:  pgscan_kswapd_dma32           |  138617 | 156351   |
:  pgscan_kswapd_normal          |   30593 |  27955   |
:  pgscan_kswapd_movable         |       0 |      0   |
:  pgscan_direct_dma             |       0 |      0   |
:  pgscan_direct_dma32           |    5050 |      0   |
:  pgscan_direct_normal          |     896 |      0   |
:  pgscan_direct_movable         |       0 |      0   |
:  kswapd_steal                  |  169207 | 171883   |
:  kswapd_inodesteal             |       0 |      0   |
:  kswapd_low_wmark_hit_quickly  |      43 |     45   |
:  kswapd_high_wmark_hit_quickly |       1 |      0   |
:  allocstall                    |      32 |      0   |
:
:
: As you can see, in the default case there were 32 direct reclaim
: (allocstal= l) and its worst latency was 517.762 usecs.  This value may be
: larger if a process would sleep or issue I/O in the direct reclaim path.
: OTOH, ii the other case where I add extra free bytes, there were no direct
: reclaim and its worst latency was 20.775 usecs.
:
: In this test case, we can avoid direct reclaim and keep a latency low.

Signed-off-by: Rik van Riel<riel@redhat.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Tested-by: Satoru Moriya <satoru.moriya@hds.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: fix page-faults detection in swap-token logic
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:44 +0000 (15:49 +1100)]
mm: fix page-faults detection in swap-token logic

After commit v2.6.36-5896-gd065bd8 "mm: retry page fault when blocking on
disk transfer" we usually wait in page-faults without mmap_sem held, so
all swap-token logic was broken, because it based on using
rwsem_is_locked(&mm->mmap_sem) as sign of in progress page-faults.

Add an atomic counter of in progress page-faults for mm to the mm_struct
with swap-token.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-tracepoint: fix documentation and examples
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:44 +0000 (15:49 +1100)]
mm-tracepoint: fix documentation and examples

We renamed the page-free mm tracepoints.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-tracepoint: rename page-free events
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:44 +0000 (15:49 +1100)]
mm-tracepoint: rename page-free events

Rename mm_page_free_direct into mm_page_free and mm_pagevec_free into
mm_page_free_batched

Since v2.6.33-5426-gc475dab the kernel triggers mm_page_free_direct for
all freed pages, not only for directly freed.  So, let's name it properly.
 For pages freed via page-list we also trigger mm_page_free_batched event.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: remove unused pagevec_free
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:43 +0000 (15:49 +1100)]
mm: remove unused pagevec_free

It not exported and now nobody uses it.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-add-free_hot_cold_page_list-helper-v3
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:43 +0000 (15:49 +1100)]
mm-add-free_hot_cold_page_list-helper-v3

v3: Always free pages in reverse order.
    The most recently added struct page, the most likely to be hot.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-add-free_hot_cold_page_list-helper-v2
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:43 +0000 (15:49 +1100)]
mm-add-free_hot_cold_page_list-helper-v2

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm: add free_hot_cold_page_list() helper
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:42 +0000 (15:49 +1100)]
mm: add free_hot_cold_page_list() helper

This patch adds helper free_hot_cold_page_list() to free list of 0-order
pages.  It frees pages directly from list without temporary page-vector.
It also calls trace_mm_pagevec_free() to simulate pagevec_free()
behaviour.

bloat-o-meter:

add/remove: 1/1 grow/shrink: 1/3 up/down: 267/-295 (-28)
function                                     old     new   delta
free_hot_cold_page_list                        -     264    +264
get_page_from_freelist                      2129    2132      +3
__pagevec_free                               243     239      -4
split_free_page                              380     373      -7
release_pages                                606     510     -96
free_page_list                               188       -    -188

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agovmscan: activate executable pages after first usage
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:41 +0000 (15:49 +1100)]
vmscan: activate executable pages after first usage

Logic added in commit 8cab4754d24a0 ("vmscan: make mapped executable pages
the first class citizen") was noticeably weakened in commit
645747462435d84 ("vmscan: detect mapped file pages used only once").

Currently these pages can become "first class citizens" only after second
usage.  After this patch page_check_references() will activate they after
first usage, and executable code gets yet better chance to stay in memory.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agovmscan: promote shared file mapped pages
Konstantin Khlebnikov [Fri, 16 Dec 2011 04:49:41 +0000 (15:49 +1100)]
vmscan: promote shared file mapped pages

Commit 645747462435 ("vmscan: detect mapped file pages used only once")
greatly decreases lifetime of single-used mapped file pages.
Unfortunately it also decreases life time of all shared mapped file pages.
Because after commit bf3f3bc5e7347 ("mm: don't mark_page_accessed
in fault path") page-fault handler does not mark page active or even
referenced.

Thus page_check_references() activates file page only if it was used twice
while it stays in inactive list, meanwhile it activates anon pages after
first access.  Inactive list can be small enough, this way reclaimer can
accidentally throw away any widely used page if it wasn't used twice in
short period.

After this patch page_check_references() also activate file mapped page at
first inactive list scan if this page is already used multiple times via
several ptes.

I found this while trying to fix degragation in rhel6 (~2.6.32) from rhel5
(~2.6.18).  There a complete mess with >100 web/mail/spam/ftp containers,
they share all their files but there a lot of anonymous pages: ~500mb
shared file mapped memory and 15-20Gb non-shared anonymous memory.  In
this situation major-pagefaults are very costly, because all containers
share the same page.  In my load kernel created a disproportionate
pressure on the file memory, compared with the anonymous, they equaled
only if I raise swappiness up to 150 =)

These patches actually wasn't helped a lot in my problem, but I saw
noticable (10-20 times) reduce in count and average time of
major-pagefault in file-mapped areas.

Actually both patches are fixes for commit v2.6.33-5448-g6457474, because
it was aimed at one scenario (singly used pages), but it breaks the logic
in other scenarios (shared and/or executable pages)

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm/page-writeback.c: make determine_dirtyable_memory static again
Johannes Weiner [Fri, 16 Dec 2011 04:49:41 +0000 (15:49 +1100)]
mm/page-writeback.c: make determine_dirtyable_memory static again

The tracing ring-buffer used this function briefly, but not anymore.
Make it local to the writeback code again.

Also, move the function so that no forward declaration needs to be
reintroduced.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoslub-document-setting-min-order-with-debug_guardpage_minorder-0-checkpatch-fixes
Andrew Morton [Fri, 16 Dec 2011 04:49:40 +0000 (15:49 +1100)]
slub-document-setting-min-order-with-debug_guardpage_minorder-0-checkpatch-fixes

Cc: David Rientjes <rientjes@google.com>
ERROR: trailing whitespace
#22: FILE: Documentation/ABI/testing/sysfs-kernel-slab:348:
+^I^Ipossible depending on its characteristics. $

total: 1 errors, 0 warnings, 20 lines checked

NOTE: whitespace errors detected, you may wish to use scripts/cleanpatch or
      scripts/cleanfile

./patches/slub-document-setting-min-order-with-debug_guardpage_minorder-0.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoslub: document setting min order with debug_guardpage_minorder > 0
Stanislaw Gruszka [Fri, 16 Dec 2011 04:49:40 +0000 (15:49 +1100)]
slub: document setting min order with debug_guardpage_minorder > 0

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoMAINTAINERS: Staging: cx25821: Add L: linux-media
Joe Perches [Fri, 16 Dec 2011 04:49:40 +0000 (15:49 +1100)]
MAINTAINERS: Staging: cx25821: Add L: linux-media

Send patches to a mailing list.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agofs: remove unneeded plug in mpage_readpages()
Namjae Jeon [Fri, 16 Dec 2011 04:49:39 +0000 (15:49 +1100)]
fs: remove unneeded plug in mpage_readpages()

The block plug in mpage_readpages() is duplicates the one in read_pages().

Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Amit Sahrawat <amit.sahrawat83@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodrivers/scsi/mpt2sas/mpt2sas_base.c: fix mismatch in mpt2sas_base_hard_reset_handler...
Alexey Khoroshilov [Fri, 16 Dec 2011 04:49:39 +0000 (15:49 +1100)]
drivers/scsi/mpt2sas/mpt2sas_base.c: fix mismatch in mpt2sas_base_hard_reset_handler() mutex lock-unlock

If ioc->pci_error_recovery is set, goto out in
mpt2sas_base_hard_reset_handler() leads to unlock unheld
ioc->reset_in_progress_mutex.

Fix the issue by jumping afer mutex_unlock() call.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodrivers/scsi/sg.c: convert to kstrtoul_from_user()
Stephen Boyd [Fri, 16 Dec 2011 04:49:39 +0000 (15:49 +1100)]
drivers/scsi/sg.c: convert to kstrtoul_from_user()

Instead of open coding this function use kstrtoul_from_user() directly.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: Douglas Gilbert <dougg@torque.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodrivers/scsi/aacraid/commctrl.c: fix mem leak in aac_send_raw_srb()
Jesper Juhl [Fri, 16 Dec 2011 04:49:38 +0000 (15:49 +1100)]
drivers/scsi/aacraid/commctrl.c: fix mem leak in aac_send_raw_srb()

We leak in drivers/scsi/aacraid/commctrl.c::aac_send_raw_srb() :

We allocate memory:
        ...
                        struct user_sgmap* usg;
                        usg = kmalloc(actual_fibsize - sizeof(struct aac_srb)
                          + sizeof(struct sgmap), GFP_KERNEL);
and then neglect to free it:
        ...
                        for (i = 0; i < usg->count; i++) {
                                u64 addr;
                                void* p;
                                if (usg->sg[i].count >
                                    ((dev->adapter_info.options &
                                     AAC_OPT_NEW_COMM) ?
                                      (dev->scsi_host_ptr->max_sectors << 9) :
                                      65536)) {
                                        rcode = -EINVAL;
                                        goto cleanup;
        ... this 'goto' makes 'usg' go out of scope and leak the memory we
            allocated.
            Other exits properly kfree(usg), it's just here it is neglected.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodrivers/scsi/megaraid.c: fix sparse warnings
Randy Dunlap [Fri, 16 Dec 2011 04:49:38 +0000 (15:49 +1100)]
drivers/scsi/megaraid.c: fix sparse warnings

Fix sparse warnings of right shift bigger than source value size:

drivers/scsi/megaraid.c:311:65: warning: right shift by bigger than source value
drivers/scsi/megaraid.c:313:65: warning: right shift by bigger than source value
drivers/scsi/megaraid.c:317:67: warning: right shift by bigger than source value
drivers/scsi/megaraid.c:319:67: warning: right shift by bigger than source value

Patch suggestion from email by Al Viro:

"Since both are claimed to be strings, I really suspect that this >> 8 is
misspelled >> 4 and they have a character followed by pair of two-digit
packed decimals in there..."

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoscsi: fix a header to include linux/types.h
Alexander Shishkin [Fri, 16 Dec 2011 04:49:38 +0000 (15:49 +1100)]
scsi: fix a header to include linux/types.h

For headers that get exported to userland and make use of u32 style
type names, it is advised to include linux/types.h.

This fixes a headers_check warning.

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoparisc, exec: remove redundant set_fs(USER_DS)
Mathias Krause [Fri, 16 Dec 2011 04:49:37 +0000 (15:49 +1100)]
parisc, exec: remove redundant set_fs(USER_DS)

The address limit is already set in flush_old_exec() so those calls to
set_fs(USER_DS) are redundant.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoext4: use proper little-endian bitops
Akinobu Mita [Fri, 16 Dec 2011 04:49:37 +0000 (15:49 +1100)]
ext4: use proper little-endian bitops

ext4_{set,clear}_bit() is defined as __test_and_{set,clear}_bit_le() for
ext4.  Only two ext4_{set,clear}_bit() calls check the return value.  The
rest of calls ignore the return value and they can be replaced with
__{set,clear}_bit_le().

This changes ext4_{set,clear}_bit() from __test_and_{set,clear}_bit_le()
to __{set,clear}_bit_le() and introduces ext4_test_and_{set,clear}_bit()
for the two places where old bit needs to be returned.

This ext4_{set,clear}_bit() change is considered safe, because if someone
uses these macros without noticing the change, new ext4_{set,clear}_bit
don't have return value and causes compiler errors where the return value
is used.

This also removes unused ext4_find_first_zero_bit().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodebugobjects: Fix selftest for static warnings
Stephen Boyd [Fri, 16 Dec 2011 04:49:36 +0000 (15:49 +1100)]
debugobjects: Fix selftest for static warnings

debugobjects is now printing a warning when a fixup for a NOTAVAILABLE
object is run.  This causes the selftest to fail like:

[    0.000000] ODEBUG: selftest warnings failed 4 != 5

We could just increase the number of warnings that the selftest is
expecting to see because that is actually what has changed.  But, it turns
out that fixup_activate() was written with inverted logic and thus a fixup
for a static object returned 1 indicating the object had been fixed, and 0
otherwise.  Fix the logic to be correct and update the counts to reflect
that nothing needed fixing for a static object.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoipc-mqueue-update-maximums-for-the-mqueue-subsystem-checkpatch-fixes
Andrew Morton [Fri, 16 Dec 2011 04:49:36 +0000 (15:49 +1100)]
ipc-mqueue-update-maximums-for-the-mqueue-subsystem-checkpatch-fixes

Cc: Amerigo Wang <amwang@redhat.com>
ERROR: Macros with complex values should be enclosed in parenthesis
#87: FILE: include/linux/ipc_namespace.h:126:
+#define DFLT_MSGSIZEMAX 1024*1024

ERROR: Macros with complex values should be enclosed in parenthesis
#88: FILE: include/linux/ipc_namespace.h:127:
+#define HARD_MSGSIZEMAX      16*1024*1024

total: 2 errors, 0 warnings, 75 lines checked

./patches/ipc-mqueue-update-maximums-for-the-mqueue-subsystem.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Doug Ledford <dledford@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoipc-mqueue-update-maximums-for-the-mqueue-subsystem-fix
Stephen Rothwell [Fri, 16 Dec 2011 04:49:36 +0000 (15:49 +1100)]
ipc-mqueue-update-maximums-for-the-mqueue-subsystem-fix

ipc/mqueue.c: In function 'mqueue_get_inode':
ipc/mqueue.c:154:4: error: implicit declaration of function 'vmalloc'
ipc/mqueue.c:154:19: warning: assignment makes pointer from integer without=
 a cast
ipc/mqueue.c: In function 'mqueue_evict_inode':
ipc/mqueue.c:278:3: error: implicit declaration of function 'vfree'

Caused by commit 8a53f9442429 ("ipc/mqueue: update maximums for the
mqueue subsystem").  See Rule 1 in Documentation/SubmitChecklist.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Doug Ledford <dledford@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoipc/mqueue: update maximums for the mqueue subsystem
Doug Ledford [Fri, 16 Dec 2011 04:49:35 +0000 (15:49 +1100)]
ipc/mqueue: update maximums for the mqueue subsystem

Commit b231cca4381ee ("message queues: increase range limits") changed the
maximum size of a message in a message queue from INT_MAX to 8192*128.
Unfortunately, we had customers that relied on a size much larger than
8192*128 on their production systems.  After reviewing POSIX, we found
that it is silent on the maximum message size.  We did find a couple other
areas in which it was not silent.  Fix up the mqueue maximums so that the
customer's system can continue to work, and document both the POSIX and
real world requirements in ipc_namespace.h so that we don't have this
issue crop back up.

Also, commit 9cf18e1dd74c ("ipc: HARD_MSGMAX should be higher not lower on
64bit") fiddled with HARD_MSGMAX without realizing that the number was
intentionally in place to limit the msg queue depth to one that was small
enough to kmalloc an array of pointers (hence why we divided 128k by
sizeof(long)).  If we wish to meet POSIX requirements, we have no choice
but to change our allocation to a vmalloc instead (at least for the large
queue size case).  With that, it's possible to increase our allowed
maximum to the POSIX requirements (or more if we choose).

Signed-off-by: Doug Ledford <dledford@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Joe Korty <joe.korty@ccur.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoipc/mqueue: enforce hard limits
Doug Ledford [Fri, 16 Dec 2011 04:49:35 +0000 (15:49 +1100)]
ipc/mqueue: enforce hard limits

In two places we don't enforce the hard limits for CAP_SYS_RESOURCE apps.
In preparation for making more reasonable hard limits, start enforcing
them even on CAP_SYS_RESOURCE.

Signed-off-by: Doug Ledford <dledford@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Joe Korty <joe.korty@ccur.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoipc/mqueue: switch back to using non-max values on create
Doug Ledford [Fri, 16 Dec 2011 04:49:35 +0000 (15:49 +1100)]
ipc/mqueue: switch back to using non-max values on create

Commit b231cca4381ee15e ("message queues: increase range limits") changed
how we create a queue that does not include an attr struct passed to open
so that it creates the queue with whatever the maximum values are.
However, if the admin has set the maximums to allow flexibility in
creating a queue (aka, both a large size and large queue are allowed, but
combined they create a queue too large for the RLIMIT_MSGQUEUE of the
user), then attempts to create a queue without an attr struct will fail.
Switch back to using acceptable defaults regardless of what the maximums
are.

Signed-off-by: Doug Ledford <dledford@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Joe Korty <joe.korty@ccur.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoipc/mqueue: cleanup definition names and locations
Doug Ledford [Fri, 16 Dec 2011 04:49:34 +0000 (15:49 +1100)]
ipc/mqueue: cleanup definition names and locations

We had a customer come up with a problem while trying to upgrade from our
2.6.18 kernel to our 2.6.32 kernel.  In diagnosing their problem, it was
determined that when commit b231cca4 ("message queues: increase range
limits") changed the msg size max from INT_MAX to 8192*128, that's what
broke their setup.

While fixing this problem, testing showed that if you increase the max
values of a msg queue, then attempt to create one without an attr struct
passed in to the open call, it could fail because it sets the queue size
to the max of both the msg size and queue size.  If these are large
enough, they over run the default RLIMIT_MSGQUEUE.  This change was also
introduced in the b231cca4 ("message queues: increase range limits")
commit.

We then found that the msg queue limits were not all being enforced on
CAP_SYS_RESOURCE apps.

Finally, we found that commit 9cf18e1d ("ipc: HARD_MSGMAX should be higher
not lower on 64bit") fiddled with HARD_MSGMAX without realizing that the
reason it was set to what it was, was to avoid trying to kmalloc a chunk
larger than 128K.

So this series of patches cleans up the various defines, takes us back to
having a larger HARD_MSGSIZEMAX, goes back to using a separate define for
the case where a user doesn't pass in an attr struct in case the maxes
have been raised too large for RLIMIT_MSGQUEUE, enforces the maximums on
CAP_SYS_RESOURCE apps, uses vmalloc instead of kmalloc when the msg
pointer array is too large, and documents all of this so it shouldn't
happen again.

This patch:

The various defines for minimums and maximums of the sysctl controllable
mqueue values are scattered amongst different files and named
inconsistently.  Move them all into ipc_namespace.h and make them have
consistent names.  Additionally, make the number of queues per namespace
also have a minimum and maximum and use the same sysctl function as the
other two settable variables.

Signed-off-by: Doug Ledford <dledford@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Joe Korty <joe.korty@ccur.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomerge_config.sh: fix bug in final check
John Stultz [Fri, 16 Dec 2011 04:49:34 +0000 (15:49 +1100)]
merge_config.sh: fix bug in final check

Arnaud Lacombe pointed out the final checking that the requested configs
were included in the final .config was broken.

The example was that if you had a fragment that disabled
CONFIG_DECOMPRESS_GZIP applied to a normal defconfig, there would be no
final warning that CONFIG_DECOMPRESS_GZIP was acutally set in the final
.config.

This bug was introduced by me in v3 of the original patch, and the
following patch reverts the invalid change.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reported-by: Arnaud Lacombe <lacombar@gmail.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomerge_config.sh: whitespace cleanup
Darren Hart [Fri, 16 Dec 2011 04:49:33 +0000 (15:49 +1100)]
merge_config.sh: whitespace cleanup

Fix whitespace usage in the clean_up routine.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomerge_config.sh: use signal names compatible with dash and bash
Darren Hart [Fri, 16 Dec 2011 04:49:33 +0000 (15:49 +1100)]
merge_config.sh: use signal names compatible with dash and bash

The SIGHUP SIGINT and SIGTERM names caused failures when running
merge_config.sh with the dash shell.  Dropping the "SIG" component makes
the script work in both bash and dash.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agokconfig: add merge_config.sh script
john stultz [Fri, 16 Dec 2011 04:49:33 +0000 (15:49 +1100)]
kconfig: add merge_config.sh script

After noticing almost every distro has their own method of managing config
fragments, I went looking at some best practices, and wanted to try to
consolidate some of the different approaches so this fairly simple
infrastructure can be shared (and new distros/build systems don't have to
implement yet another config fragment merge script).

This script is most influenced by the Windriver tools used in the Yocto
Project, reusing some portions found there.

This script merges multiple config fragments, warning on any overridden
values.  It then sets any unspecified values to their default, then
finally checks to make sure no specified value was dropped due to
unsatisfied dependencies.

I'm sure this implementation won't work for everyone, and I expect it will
need to evolve to adapt for various use cases.  But I think its a
reasonable starting point.

Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Reinhard Tartler <Reinhard.Tartler@informatik.uni-erlangen.de>
Cc: Dmitry Fink <Dmitry.Fink@palm.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Bruce Ashfield <Bruce.Ashfield@windriver.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoia64, exec: remove redundant set_fs(USER_DS)
Mathias Krause [Fri, 16 Dec 2011 04:49:32 +0000 (15:49 +1100)]
ia64, exec: remove redundant set_fs(USER_DS)

The address limit is already set in flush_old_exec() so this
set_fs(USER_DS) is redundant.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agotick-sched: add specific do_timer_cpu value for nohz off mode
Dimitri Sivanich [Fri, 16 Dec 2011 04:49:32 +0000 (15:49 +1100)]
tick-sched: add specific do_timer_cpu value for nohz off mode

Show and modify the tick_do_timer_cpu via sysfs.  This determines the cpu
on which global time (jiffies) updates occur.  Modification can only be
done on systems with nohz mode turned off.

While not necessarily harmful, doing jiffies updates on an application cpu
does cause some extra overhead that HPC benchmarking people notice.  They
prefer to have OS activity isolated to certain cpus.  They like
reproducibility of results, and having jiffies updates bouncing around
introduces variability.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agohrtimers: Special-case zero length sleeps
Matthew Garrett [Fri, 16 Dec 2011 04:49:32 +0000 (15:49 +1100)]
hrtimers: Special-case zero length sleeps

sleep(0) is a common construct used by applications that want to trigger
the scheduler.  sched_yield() might make more sense, but only appeared in
POSIX.1-2001 and so plenty of example code still uses the sleep(0) form.

This wouldn't normally be a problem, but it means that event-driven
applications that are merely trying to avoid starving other processes may
actually end up sleeping due to having large timer_slack values.  Special-
casing this seems reasonable.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoarm, exec: remove redundant set_fs(USER_DS)
Mathias Krause [Fri, 16 Dec 2011 04:49:31 +0000 (15:49 +1100)]
arm, exec: remove redundant set_fs(USER_DS)

The address limit is already set in flush_old_exec() so this
set_fs(USER_DS) is redundant.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoarch/arm/mach-ux500/mbox-db5500.c: world-writable sysfs fifo file
Vasiliy Kulikov [Fri, 16 Dec 2011 04:49:31 +0000 (15:49 +1100)]
arch/arm/mach-ux500/mbox-db5500.c: world-writable sysfs fifo file

Don't allow everybody to use a modem.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodrivers-platform-x86-sony-laptopc-fix-scancodes-v2-checkpatch-fixes
Andrew Morton [Fri, 16 Dec 2011 04:49:31 +0000 (15:49 +1100)]
drivers-platform-x86-sony-laptopc-fix-scancodes-v2-checkpatch-fixes

Cc: Dan Carpenter <dan.carpenter@oracle.com>
ERROR: code indent should use tabs where possible
#34: FILE: drivers/platform/x86/sony-laptop.c:395:
+                   remap the key */$

total: 1 errors, 0 warnings, 28 lines checked

NOTE: whitespace errors detected, you may wish to use scripts/cleanpatch or
      scripts/cleanfile

./patches/drivers-platform-x86-sony-laptopc-fix-scancodes-v2.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: John Hughes <john@Calva.COM>
Cc: John Hughes <john@calva.com>
Cc: John Hughes <john@calvaedi.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Mattia Dongili <malattia@linux.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodrivers-platform-x86-sony-laptopc-fix-scancodes-v2
John Hughes [Fri, 16 Dec 2011 04:49:30 +0000 (15:49 +1100)]
drivers-platform-x86-sony-laptopc-fix-scancodes-v2

Signed-off-by: John Hughes <john@calva.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mattia Dongili <malattia@linux.it>
Cc: John Hughes <john@Calva.COM>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodrivers-platform-x86-sony-laptopc-fix-scancodes-checkpatch-fixes
Andrew Morton [Fri, 16 Dec 2011 04:49:30 +0000 (15:49 +1100)]
drivers-platform-x86-sony-laptopc-fix-scancodes-checkpatch-fixes

ERROR: do not use assignment in if condition
#59: FILE: drivers/platform/x86/sony-laptop.c:384:
+ if ((scancode = sony_laptop_input_index[event]) != -1) {

total: 1 errors, 0 warnings, 39 lines checked

./patches/drivers-platform-x86-sony-laptopc-fix-scancodes.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agodrivers/platform/x86/sony-laptop.c: fix scancodes
John Hughes [Fri, 16 Dec 2011 04:49:30 +0000 (15:49 +1100)]
drivers/platform/x86/sony-laptop.c: fix scancodes

The scancodes returned by the sony-laptop driver for function keys did not
match the scancodes used to remap keys.  Also, since the scancode was sent
to the input subsystem after the mapped keysym the /lib/udev/keymap
utility was confused about which scancode to report for which keysym.

This patch fixes the driver so the correct scancode is shown for each key.
 It also adds to the documentation a description of where to find the
scancodes.

Before the patch FN/E returned scancode 0x1B, but to remap scancode 0x14
had to be used.

Signed-off-by: John Hughes <john@calva.com>
Cc: Mattia Dongili <malattia@linux.it>
Cc: Matthew Garrett <mjg@redhat.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agox86, olpc: add debugfs interface for EC commands
Daniel Drake [Fri, 16 Dec 2011 04:49:29 +0000 (15:49 +1100)]
x86, olpc: add debugfs interface for EC commands

Add a debugfs interface for sending commands to the OLPC Embedded
Controller (EC) and reading the responses.  The EC provides functionality
for machine identification, battery and AC control, wakeup control, etc.

Having a debugfs interface available is useful for EC development and
debugging.

Based on code by Paul Fox.

Signed-off-by: Paul Fox <pgf@laptop.org>
Signed-off-by: Daniel Drake <dsd@laptop.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andres Salomon <dilinger@queued.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm-vmallocc-eliminate-extra-loop-in-pcpu_get_vm_areas-error-path-fix
Andrew Morton [Fri, 16 Dec 2011 04:49:29 +0000 (15:49 +1100)]
mm-vmallocc-eliminate-extra-loop-in-pcpu_get_vm_areas-error-path-fix

remove now-unneeded tests

Cc: Kautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agomm/vmalloc.c: eliminate extra loop in pcpu_get_vm_areas error path
Kautuk Consul [Fri, 16 Dec 2011 04:49:29 +0000 (15:49 +1100)]
mm/vmalloc.c: eliminate extra loop in pcpu_get_vm_areas error path

If either of the vas or vms arrays are not properly kzalloced, then the
code jumps to the err_free label.

The err_free label runs a loop to check and free each of the array members
of the vas and vms arrays which is not required for this situation as none
of the array members have been allocated till this point.

Eliminate the extra loop we have to go through by introducing a new label
err_free2 and then jumping to it.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agox86-olpc-xo15-sci-enable-lid-close-wakeup-control-through-sysfs-v2
Daniel Drake [Fri, 16 Dec 2011 04:49:28 +0000 (15:49 +1100)]
x86-olpc-xo15-sci-enable-lid-close-wakeup-control-through-sysfs-v2

v2: Fix sscanf usage error and add an explanatory comment in the code, both pointed out by Andrew Morton. Thanks!

Signed-off-by: Daniel Drake <dsd@laptop.org>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agox86-olpc-xo15-sci-enable-lid-close-wakeup-control-through-sysfs-fix
Andrew Morton [Fri, 16 Dec 2011 04:49:28 +0000 (15:49 +1100)]
x86-olpc-xo15-sci-enable-lid-close-wakeup-control-through-sysfs-fix

fix sscanf checking

Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Daniel Drake <dsd@laptop.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agox86, olpc-xo15-sci: enable lid close wakeup control through sysfs
Daniel Drake [Fri, 16 Dec 2011 04:49:28 +0000 (15:49 +1100)]
x86, olpc-xo15-sci: enable lid close wakeup control through sysfs

Like most systems, OLPC's ACPI LID switch wakes up the system when the lid
is opened, but not when it is closed.

Under OLPC's opportunistic suspend model, the lid may be closed while the
system was oportunistically suspended with the screen running.  In this
event, we want to wake up to turn the screen off.

Enable control of normal ACPI wakeups through lid close events through a
new sysfs attribute "lid_wake_on_closed".  When set, and when LID wakeups
are enabled through ACPI, the system will wake up on both open and close
lid events.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoarch/x86/platform/iris/iris.c: register a platform device and a platform driver
Shérab [Fri, 16 Dec 2011 04:49:27 +0000 (15:49 +1100)]
arch/x86/platform/iris/iris.c: register a platform device and a platform driver

This makes the iris driver use the platform API, so it is properly exposed
in /sys.

[akpm@linux-foundation.org: remove commented-out code, add missing space to printk, clean up code layout]
Signed-off-by: Shérab <Sebastien.Hinderer@ens-lyon.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
12 years agoacerhdf: lowered default temp fanon/fanoff values
Peter Feuerer [Fri, 16 Dec 2011 04:49:27 +0000 (15:49 +1100)]
acerhdf: lowered default temp fanon/fanoff values

Due to new supported hardware, of which the actual temperature limits of
processor, harddisk and other components are unknown, it feels safer with
lower fanon / fanoff settings.

It won't change much for most people, already using acerhdf, as they use
their own fanon/fanoff variable settings when loading the module.

Furthermore seems like kernel and userspace tools have been improved to
work more efficient and netbooks don't get so hot anymore.

Signed-off-by: Peter Feuerer <peter@piie.net>
Acked-by: Borislav Petkov <petkovbb@gmail.com>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>