mm: vmscan: when reclaiming for compaction, ensure there are sufficient free pages available

commit fe4b1b244bdb96136855f2c694071cb09d140766 upstream.

Stable note: Not tracked on Bugzilla. THP and compaction was found to
	aggressively reclaim pages and stall systems under different
	situations that was addressed piecemeal over time. This patch
	addresses a problem where the fix regressed THP allocation
	success rates.

In commit e0887c19 ("vmscan: limit direct reclaim for higher order
allocations"), Rik noted that reclaim was too aggressive when THP was
enabled.  In his initial patch he used the number of free pages to decide
if reclaim should abort for compaction.  My feedback was that reclaim and
compaction should be using the same logic when deciding if reclaim should
be aborted.

Unfortunately, this had the effect of reducing THP success rates when the
workload included something like streaming reads that continually
allocated pages.  The window during which compaction could run and return
a THP was too small.

This patch combines Rik's two patches together.  compaction_suitable() is
still used to decide if reclaim should be aborted to allow compaction is
used.  However, it will also ensure that there is a reasonable buffer of
free pages available.  This improves upon the THP allocation success rates
but bounds the number of pages that are freed for compaction.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel<riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm: vmscan: do not OOM if aborting reclaim to start compaction

commit 7335084d446b83cbcb15da80497d03f0c1dc9e21 upstream.

Stable note: Not tracked in Bugzilla. This patch makes later patches
	easier to apply but otherwise has little to justify it. The
	problem it fixes was never observed but the source of the
	theoretical problem did not exist for very long.

During direct reclaim it is possible that reclaim will be aborted so that
compaction can be attempted to satisfy a high-order allocation.  If this
decision is made before any pages are reclaimed, it is possible that 0 is
returned to the page allocator potentially triggering an OOM.  This has
not been observed but it is a possibility so this patch addresses it.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm: vmscan: check if reclaim should really abort even if compaction_ready() is true for one zone

commit 0cee34fd72c582b4f8ad8ce00645b75fb4168199 upstream.

Stable note: Not tracked on Bugzilla. THP and compaction was found to
	aggressively reclaim pages and stall systems under different
	situations that was addressed piecemeal over time.

If compaction can proceed for a given zone, shrink_zones() does not
reclaim any more pages from it.  After commit [e0c2327: vmscan: abort
reclaim/compaction if compaction can proceed], do_try_to_free_pages()
tries to finish as soon as possible once one zone can compact.

This was intended to prevent slabs being shrunk unnecessarily but there
are side-effects.  One is that a small zone that is ready for compaction
will abort reclaim even if the chances of successfully allocating a THP
from that zone is small.  It also means that reclaim can return too early
even though sc->nr_to_reclaim pages were not reclaimed.

This partially reverts the commit until it is proven that slabs are really
being shrunk unnecessarily but preserves the check to return 1 to avoid
OOM if reclaim was aborted prematurely.

[aarcange@redhat.com: This patch replaces a revert from Andrea]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vmscan: promote shared file mapped pages

commit 34dbc67a644f11ab3475d822d72e25409911e760 upstream.

Stable note: Not tracked in Bugzilla. There were reports of shared
	mapped pages being unfairly reclaimed in comparison to older kernels.
	This is being addressed over time. The specific workload being
	addressed here in described in paragraph four and while paragraph
	five says it did not help performance as such, it made a difference
	to major page faults. I'm aware of at least one bug for a large
	vendor that was due to increased major faults.

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
vmscan: activate executable pages after first usage

commit c909e99364c8b6ca07864d752950b6b4ecf6bef4 upstream.

Stable note: Not tracked in Bugzilla. There were reports of shared
	mapped pages being unfairly reclaimed in comparison to older kernels.
	This is being addressed over time.

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/vmscan.c: consider swap space when deciding whether to continue reclaim

commit 86cfd3a45042ab242d47f3935a02811a402beab6 upstream.

Stable note: Not tracked in Bugzilla. This patch reduces kswapd CPU
	usage on swapless systems with high anonymous memory usage.

It's pointless to continue reclaiming when we have no swap space and lots
of anon pages in the inactive list.

Without this patch, it is possible when swap is disabled to continue
trying to reclaim when there are only anonymous pages in the system even
though that will not make any progress.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm: test PageSwapBacked in lumpy reclaim

commit 043bcbe5ec51e0478ef2b44acef17193e01d7f70 upstream.

Stable note: Not tracked in Bugzilla. There were reports of shared
	mapped pages being unfairly reclaimed in comparison to older kernels.
	This is being addressed over time. Even though the subject
	refers to lumpy reclaim, it impacts compaction as well.

Lumpy reclaim does well to stop at a PageAnon when there's no swap, but
better is to stop at any PageSwapBacked, which includes shmem/tmpfs too.

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
mm: vmscan: convert global reclaim to per-memcg LRU lists

commit b95a2f2d486d0d768a92879c023a03757b9c7e58 upstream - WARNING: this is a substitute patch.

Stable note: Not tracked in Bugzilla. This is a partial backport of an
	upstream commit addressing a completely different issue
	that accidentally contained an important fix. The workload
	this patch helps was memcached when IO is started in the
	background. memcached should stay resident but without this patch
	it gets swapped. Sometimes this manifests as a drop in throughput
	but mostly it was observed through /proc/vmstat.

Commit [246e87a9: memcg: fix get_scan_count() for small targets] was meant
to fix a problem whereby small scan targets on memcg were ignored causing
priority to raise too sharply. It forced scanning to take place if the
target was small, memcg or kswapd.

From the time it was introduced it caused excessive reclaim by kswapd
with workloads being pushed to swap that previously would have stayed
resident. This was accidentally fixed in commit [b95a2f2d: mm: vmscan:
convert global reclaim to per-memcg LRU lists] by making it harder for
kswapd to force scan small targets but that patchset is not suitable for
backporting. This was later changed again by commit [90126375: mm/vmscan:
push lruvec pointer into get_scan_count()] into a format that looks
like it would be a straight-forward backport but there is a subtle
difference due to the use of lruvecs.

The impact of the accidental fix is to make it harder for kswapd to force
scan small targets by taking zone->all_unreclaimable into account. This
patch is the closest equivalent available based on what is backported.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpusets: avoid looping when storing to mems_allowed if one node remains set

commit 89e8a244b97e48f1f30e898b6f32acca477f2a13 upstream.

Stable note: Not tracked in Bugzilla. [get|put]_mems_allowed() is
	extremely expensive and severely impacted page allocator performance.
	This is part of a series of patches that reduce page allocator
	overhead.

{get,put}_mems_allowed() exist so that general kernel code may locklessly
access a task's set of allowable nodes without having the chance that a
concurrent write will cause the nodemask to be empty on configurations
where MAX_NUMNODES > BITS_PER_LONG.

This could incur a significant delay, however, especially in low memory
conditions because the page allocator is blocking and reclaim requires
get_mems_allowed() itself.  It is not atypical to see writes to
cpuset.mems take over 2 seconds to complete, for example.  In low memory
conditions, this is problematic because it's one of the most imporant
times to change cpuset.mems in the first place!

The only way a task's set of allowable nodes may change is through cpusets
by writing to cpuset.mems and when attaching a task to a generic code is
not reading the nodemask with get_mems_allowed() at the same time, and
then clearing all the old nodes.  This prevents the possibility that a
reader will see an empty nodemask at the same time the writer is storing a
new nodemask.

If at least one node remains unchanged, though, it's possible to simply
set all new nodes and then clear all the old nodes.  Changing a task's
nodemask is protected by cgroup_mutex so it's guaranteed that two threads
are not changing the same task's nodemask at the same time, so the
nodemask is guaranteed to be stored before another thread changes it and
determines whether a node remains set or not.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Paul Menage <paul@paulmenage.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpusets: stall when updating mems_allowed for mempolicy or disjoint nodemask

commit b246272ecc5ac68c743b15c9e41a2275f7ce70e2 upstream.

Stable note: Not tracked in Bugzilla. [get|put]_mems_allowed() is extremely
	expensive and severely impacted page allocator performance. This is
	part of a series of patches that reduce page allocator overhead.

Kernels where MAX_NUMNODES > BITS_PER_LONG may temporarily see an empty
nodemask in a tsk's mempolicy if its previous nodemask is remapped onto a
new set of allowed cpuset nodes where the two nodemasks, as a result of
the remap, are now disjoint.

c0ff7453bb5c ("cpuset,mm: fix no node to alloc memory when changing
cpuset's mems") adds get_mems_allowed() to prevent the set of allowed
nodes from changing for a thread.  This causes any update to a set of
allowed nodes to stall until put_mems_allowed() is called.

This stall is unncessary, however, if at least one node remains unchanged
in the update to the set of allowed nodes.  This was addressed by
89e8a244b97e ("cpusets: avoid looping when storing to mems_allowed if one
node remains set"), but it's still possible that an empty nodemask may be
read from a mempolicy because the old nodemask may be remapped to the new
nodemask during rebind.  To prevent this, only avoid the stall if there is
no mempolicy for the thread being changed.

This is a temporary solution until all reads from mempolicy nodemasks can
be guaranteed to not be empty without the get_mems_allowed()
synchronization.

Also moves the check for nodemask intersection inside task_lock() so that
tsk->mems_allowed cannot change.  This ensures that nothing can set this
tsk's mems_allowed out from under us and also protects tsk->mempolicy.

Reported-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpuset: mm: reduce large amounts of memory barrier related damage v3

commit cc9a6c8776615f9c194ccf0b63a0aa5628235545 upstream.

Stable note:  Not tracked in Bugzilla. [get|put]_mems_allowed() is extremely
	expensive and severely impacted page allocator performance. This
	is part of a series of patches that reduce page allocator overhead.

Commit c0ff7453bb5c ("cpuset,mm: fix no node to alloc memory when
changing cpuset's mems") wins a super prize for the largest number of
memory barriers entered into fast paths for one commit.

[get|put]_mems_allowed is incredibly heavy with pairs of full memory
barriers inserted into a number of hot paths.  This was detected while
investigating at large page allocator slowdown introduced some time
after 2.6.32.  The largest portion of this overhead was shown by
oprofile to be at an mfence introduced by this commit into the page
allocator hot path.

For extra style points, the commit introduced the use of yield() in an
implementation of what looks like a spinning mutex.

This patch replaces the full memory barriers on both read and write
sides with a sequence counter with just read barriers on the fast path
side.  This is much cheaper on some architectures, including x86.  The
main bulk of the patch is the retry logic if the nodemask changes in a
manner that can cause a false failure.

While updating the nodemask, a check is made to see if a false failure
is a risk.  If it is, the sequence number gets bumped and parallel
allocators will briefly stall while the nodemask update takes place.

In a page fault test microbenchmark, oprofile samples from
__alloc_pages_nodemask went from 4.53% of all samples to 1.15%.  The
actual results were

                             3.3.0-rc3          3.3.0-rc3
                             rc3-vanilla        nobarrier-v2r1
    Clients   1 UserTime       0.07 (  0.00%)   0.08 (-14.19%)
    Clients   2 UserTime       0.07 (  0.00%)   0.07 (  2.72%)
    Clients   4 UserTime       0.08 (  0.00%)   0.07 (  3.29%)
    Clients   1 SysTime        0.70 (  0.00%)   0.65 (  6.65%)
    Clients   2 SysTime        0.85 (  0.00%)   0.82 (  3.65%)
    Clients   4 SysTime        1.41 (  0.00%)   1.41 (  0.32%)
    Clients   1 WallTime       0.77 (  0.00%)   0.74 (  4.19%)
    Clients   2 WallTime       0.47 (  0.00%)   0.45 (  3.73%)
    Clients   4 WallTime       0.38 (  0.00%)   0.37 (  1.58%)
    Clients   1 Flt/sec/cpu  497620.28 (  0.00%) 520294.53 (  4.56%)
    Clients   2 Flt/sec/cpu  414639.05 (  0.00%) 429882.01 (  3.68%)
    Clients   4 Flt/sec/cpu  257959.16 (  0.00%) 258761.48 (  0.31%)
    Clients   1 Flt/sec      495161.39 (  0.00%) 517292.87 (  4.47%)
    Clients   2 Flt/sec      820325.95 (  0.00%) 850289.77 (  3.65%)
    Clients   4 Flt/sec      1020068.93 (  0.00%) 1022674.06 (  0.26%)
    MMTests Statistics: duration
    Sys Time Running Test (seconds)             135.68    132.17
    User+Sys Time Running Test (seconds)         164.2    160.13
    Total Elapsed Time (seconds)                123.46    120.87

The overall improvement is small but the System CPU time is much
improved and roughly in correlation to what oprofile reported (these
performance figures are without profiling so skew is expected).  The
actual number of page faults is noticeably improved.

For benchmarks like kernel builds, the overall benefit is marginal but
the system CPU time is slightly reduced.

To test the actual bug the commit fixed I opened two terminals.  The
first ran within a cpuset and continually ran a small program that
faulted 100M of anonymous data.  In a second window, the nodemask of the
cpuset was continually randomised in a loop.

Without the commit, the program would fail every so often (usually
within 10 seconds) and obviously with the commit everything worked fine.
With this patch applied, it also worked fine so the fix should be
functionally equivalent.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/hugetlb: fix warning in alloc_huge_page/dequeue_huge_page_vma

commit b1c12cbcd0a02527c180a862e8971e249d3b347d upstream.

Stable note: Not tracked in Bugzilla. [get|put]_mems_allowed() is extremely
	expensive and severely impacted page allocator performance. This
	is part of a series of patches that reduce page allocator overhead.

Fix a gcc warning (and bug?) introduced in cc9a6c877 ("cpuset: mm: reduce
large amounts of memory barrier related damage v3")

Local variable "page" can be uninitialized if the nodemask from vma policy
does not intersects with nodemask from cpuset.  Even if it doesn't happens
it is better to initialize this variable explicitly than to introduce
a kernel oops in a weird corner case.

mm/hugetlb.c: In function `alloc_huge_page':
mm/hugetlb.c:1135:5: warning: `page' may be used uninitialized in this function

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vmscan: fix initial shrinker size handling

commit 635697c663f38106063d5659f0cf2e45afcd4bb5 upstream.

Stable note: The commit [acf92b48: vmscan: shrinker->nr updates race and
	go wrong] aimed to reduce excessive reclaim of slab objects but
	had bug in how it treated shrinker functions that returned -1.

A shrinker function can return -1, means that it cannot do anything
without a risk of deadlock.  For example prune_super() does this if it
cannot grab a superblock refrence, even if nr_to_scan=0.  Currently we
interpret this -1 as a ULONG_MAX size shrinker and evaluate `total_scan'
according to this.  So the next time around this shrinker can cause
really big pressure.  Let's skip such shrinkers instead.

Also make total_scan signed, otherwise the check (total_scan < 0) below
never works.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux 3.0.39
scripts/Kbuild.include: Fix portability problem of "echo -e"

"echo -e" is a GNU extension. When cross-compiling the kernel on a
BSD-like operating system (Mac OS X in my case), this doesn't work.

One could install a GNU version of echo, put that in the $PATH before
the system echo and use "/usr/bin/env echo", but the solution with
printf is simpler.

Since it is no disadvantage on Linux, I hope that gets accepted even if
cross-compiling the Linux kernel on another Unix operating system is
quite a rare use case.

Signed-off-by: Bernhard Walle <bernhard@bwalle.de>
Andreas Bießmann <andreas@biessmann.de>
Signed-off-by: Michal Marek <mmarek@suse.cz>
usbdevfs: Correct amount of data copied to user in processcompl_compat

commit 2102e06a5f2e414694921f23591f072a5ba7db9f upstream.

iso data buffers may have holes in them if some packets were short, so for
iso urbs we should always copy the entire buffer, just like the regular
processcompl does.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
locks: fix checking of fcntl_setlease argument

commit 0ec4f431eb56d633da3a55da67d5c4b88886ccc7 upstream.

The only checks of the long argument passed to fcntl(fd,F_SETLEASE,.)
are done after converting the long to an int.  Thus some illegal values
may be let through and cause problems in later code.

[ They actually *don't* cause problems in mainline, as of Dave Jones's
  commit 8d657eb3b438 "Remove easily user-triggerable BUG from
  generic_setlease", but we should fix this anyway.  And this patch will
  be necessary to fix real bugs on earlier kernels. ]

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Disable function tracing during suspend/resume and hibernation, again

commit 443772d408a25af62498793f6f805ce3c559309a upstream.

If function tracing is enabled for some of the low-level suspend/resume
functions, it leads to triple fault during resume from suspend, ultimately
ending up in a reboot instead of a resume (or a total refusal to come out
of suspended state, on some machines).

This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace:
disable tracing for suspend to ram). However, the changes made by that commit
got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of
suspend/resume & hibernation code again). So, unfortunately since things are
not yet robust enough to allow tracing of low-level suspend/resume functions,
suspend/resume is still broken when ftrace is enabled.

So fix this by disabling function tracing during suspend/resume & hibernation.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
stable: update references to older 2.6 versions for 3.x

commit 2584f5212d97b664be250ad5700a2d0fee31a10d upstream.

Also add information on where the respective trees are.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	Documentation/stable_kernel_rules.txt
workqueue: perform cpu down operations from low priority cpu_notifier()

commit 6575820221f7a4dd6eadecf7bf83cdd154335eda upstream.

Currently, all workqueue cpu hotplug operations run off
CPU_PRI_WORKQUEUE which is higher than normal notifiers.  This is to
ensure that workqueue is up and running while bringing up a CPU before
other notifiers try to use workqueue on the CPU.

Per-cpu workqueues are supposed to remain working and bound to the CPU
for normal CPU_DOWN_PREPARE notifiers.  This holds mostly true even
with workqueue offlining running with higher priority because
workqueue CPU_DOWN_PREPARE only creates a bound trustee thread which
runs the per-cpu workqueue without concurrency management without
explicitly detaching the existing workers.

However, if the trustee needs to create new workers, it creates
unbound workers which may wander off to other CPUs while
CPU_DOWN_PREPARE notifiers are in progress.  Furthermore, if the CPU
down is cancelled, the per-CPU workqueue may end up with workers which
aren't bound to the CPU.

While reliably reproducible with a convoluted artificial test-case
involving scheduling and flushing CPU burning work items from CPU down
notifiers, this isn't very likely to happen in the wild, and, even
when it happens, the effects are likely to be hidden by the following
successful CPU down.

Fix it by using different priorities for up and down notifiers - high
priority for up operations and low priority for down operations.

Workqueue cpu hotplug operations will soon go through further cleanup.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>