8064 Commits

Author SHA1 Message Date
Linus Torvalds
c1ff84317f Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Peter Anvin:
 "Quite a varied little collection of fixes.  Most of them are
  relatively small or isolated; the biggest one is Mel Gorman's fixes
  for TLB range flushing.

  A couple of AMD-related fixes (including not crashing when given an
  invalid microcode image) and fix a crash when compiled with gcov"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, microcode, AMD: Unify valid container checks
  x86, hweight: Fix BUG when booting with CONFIG_GCOV_PROFILE_ALL=y
  x86/efi: Allow mapping BGRT on x86-32
  x86: Fix the initialization of physnode_map
  x86, cpu hotplug: Fix stack frame warning in check_irq_vectors_for_cpu_disable()
  x86/intel/mid: Fix X86_INTEL_MID dependencies
  arch/x86/mm/srat: Skip NUMA_NO_NODE while parsing SLIT
  mm, x86: Revisit tlb_flushall_shift tuning for page flushes except on IvyBridge
  x86: mm: change tlb_flushall_shift for IvyBridge
  x86/mm: Eliminate redundant page table walk during TLB range flushing
  x86/mm: Clean up inconsistencies when flushing TLB ranges
  mm, x86: Account for TLB flushes only when debugging
  x86/AMD/NB: Fix amd_set_subcaches() parameter type
  x86/quirks: Add workaround for AMD F16h Erratum792
  x86, doc, kconfig: Fix dud URL for Microcode data
2014-02-08 11:54:43 -08:00
Tejun Heo
1a698a4aba Merge branch 'for-3.14-fixes' into for-3.15
Pending kernfs conversion depends on fixes in for-3.14-fixes.  Pull it
into for-3.15.

Signed-off-by: Tejun Heo <tj@kernel.org>
2014-02-08 10:37:14 -05:00
Tejun Heo
073219e995 cgroup: clean up cgroup_subsys names and initialization
cgroup_subsys is a bit messier than it needs to be.

* The name of a subsys can be different from its internal identifier
  defined in cgroup_subsys.h.  Most subsystems use the matching name
  but three - cpu, memory and perf_event - use different ones.

* cgroup_subsys_id enums are postfixed with _subsys_id and each
  cgroup_subsys is postfixed with _subsys.  cgroup.h is widely
  included throughout various subsystems, it doesn't and shouldn't
  have claim on such generic names which don't have any qualifier
  indicating that they belong to cgroup.

* cgroup_subsys->subsys_id should always equal the matching
  cgroup_subsys_id enum; however, we require each controller to
  initialize it and then BUG if they don't match, which is a bit
  silly.

This patch cleans up cgroup_subsys names and initialization by doing
the followings.

* cgroup_subsys_id enums are now postfixed with _cgrp_id, and each
  cgroup_subsys with _cgrp_subsys.

* With the above, renaming subsys identifiers to match the userland
  visible names doesn't cause any naming conflicts.  All non-matching
  identifiers are renamed to match the official names.

  cpu_cgroup -> cpu
  mem_cgroup -> memory
  perf -> perf_event

* controllers no longer need to initialize ->subsys_id and ->name.
  They're generated in cgroup core and set automatically during boot.

* Redundant cgroup_subsys declarations removed.

* While updating BUG_ON()s in cgroup_init_early(), convert them to
  WARN()s.  BUGging that early during boot is stupid - the kernel
  can't print anything, even through serial console and the trap
  handler doesn't even link stack frame properly for back-tracing.

This patch doesn't introduce any behavior changes.

v2: Rebased on top of fe1217c4f3f7 ("net: net_cls: move cgroupfs
    classid handling into core").

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Acked-by: Ingo Molnar <mingo@redhat.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>
2014-02-08 10:36:58 -05:00
Joe Perches
5087c82299 slab: Make allocations with GFP_ZERO slightly more efficient
Use the likely mechanism already around valid
pointer tests to better choose when to memset
to 0 allocations with __GFP_ZERO

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2014-02-08 12:19:02 +02:00
Joonsoo Kim
8fc9cf420b slab: make more slab management structure off the slab
Now, the size of the freelist for the slab management diminish,
so that the on-slab management structure can waste large space
if the object of the slab is large.

Consider a 128 byte sized slab. If on-slab is used, 31 objects can be
in the slab. The size of the freelist for this case would be 31 bytes
so that 97 bytes, that is, more than 75% of object size, are wasted.

In a 64 byte sized slab case, no space is wasted if we use on-slab.
So set off-slab determining constraint to 128 bytes.

Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2014-02-08 12:13:25 +02:00
Joonsoo Kim
a41adfaa23 slab: introduce byte sized index for the freelist of a slab
Currently, the freelist of a slab consist of unsigned int sized indexes.
Since most of slabs have less number of objects than 256, large sized
indexes is needless. For example, consider the minimum kmalloc slab. It's
object size is 32 byte and it would consist of one page, so 256 indexes
through byte sized index are enough to contain all possible indexes.

There can be some slabs whose object size is 8 byte. We cannot handle
this case with byte sized index, so we need to restrict minimum
object size. Since these slabs are not major, wasted memory from these
slabs would be negligible.

Some architectures' page size isn't 4096 bytes and rather larger than
4096 bytes (One example is 64KB page size on PPC or IA64) so that
byte sized index doesn't fit to them. In this case, we will use
two bytes sized index.

Below is some number for this patch.

* Before *
kmalloc-512          525    640    512    8    1 : tunables   54   27    0 : slabdata     80     80      0
kmalloc-256          210    210    256   15    1 : tunables  120   60    0 : slabdata     14     14      0
kmalloc-192         1016   1040    192   20    1 : tunables  120   60    0 : slabdata     52     52      0
kmalloc-96           560    620    128   31    1 : tunables  120   60    0 : slabdata     20     20      0
kmalloc-64          2148   2280     64   60    1 : tunables  120   60    0 : slabdata     38     38      0
kmalloc-128          647    682    128   31    1 : tunables  120   60    0 : slabdata     22     22      0
kmalloc-32         11360  11413     32  113    1 : tunables  120   60    0 : slabdata    101    101      0
kmem_cache           197    200    192   20    1 : tunables  120   60    0 : slabdata     10     10      0

* After *
kmalloc-512          521    648    512    8    1 : tunables   54   27    0 : slabdata     81     81      0
kmalloc-256          208    208    256   16    1 : tunables  120   60    0 : slabdata     13     13      0
kmalloc-192         1029   1029    192   21    1 : tunables  120   60    0 : slabdata     49     49      0
kmalloc-96           529    589    128   31    1 : tunables  120   60    0 : slabdata     19     19      0
kmalloc-64          2142   2142     64   63    1 : tunables  120   60    0 : slabdata     34     34      0
kmalloc-128          660    682    128   31    1 : tunables  120   60    0 : slabdata     22     22      0
kmalloc-32         11716  11780     32  124    1 : tunables  120   60    0 : slabdata     95     95      0
kmem_cache           197    210    192   21    1 : tunables  120   60    0 : slabdata     10     10      0

kmem_caches consisting of objects less than or equal to 256 byte have
one or more objects than before. In the case of kmalloc-32, we have 11 more
objects, so 352 bytes (11 * 32) are saved and this is roughly 9% saving of
memory. Of couse, this percentage decreases as the number of objects
in a slab decreases.

Here are the performance results on my 4 cpus machine.

* Before *

 Performance counter stats for 'perf bench sched messaging -g 50 -l 1000' (10 runs):

       229,945,138 cache-misses                                                  ( +-  0.23% )

      11.627897174 seconds time elapsed                                          ( +-  0.14% )

* After *

 Performance counter stats for 'perf bench sched messaging -g 50 -l 1000' (10 runs):

       218,640,472 cache-misses                                                  ( +-  0.42% )

      11.504999837 seconds time elapsed                                          ( +-  0.21% )

cache-misses are reduced by this patchset, roughly 5%.
And elapsed times are improved by 1%.

Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2014-02-08 12:12:38 +02:00
Joonsoo Kim
f315e3fa1c slab: restrict the number of objects in a slab
To prepare to implement byte sized index for managing the freelist
of a slab, we should restrict the number of objects in a slab to be less
or equal to 256, since byte only represent 256 different values.
Setting the size of object to value equal or more than newly introduced
SLAB_OBJ_MIN_SIZE ensures that the number of objects in a slab is less or
equal to 256 for a slab with 1 page.

If page size is rather larger than 4096, above assumption would be wrong.
In this case, we would fall back on 2 bytes sized index.

If minimum size of kmalloc is less than 16, we use it as minimum object
size and give up this optimization.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2014-02-08 12:12:06 +02:00
Joonsoo Kim
e5c58dfdcb slab: introduce helper functions to get/set free object
In the following patches, to get/set free objects from the freelist
is changed so that simple casting doesn't work for it. Therefore,
introduce helper functions.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2014-02-08 12:10:35 +02:00
Joonsoo Kim
9cef2e2b65 slab: factor out calculate nr objects in cache_estimate
This logic is not simple to understand so that making separate function
helping readability. Additionally, we can use this change in the
following patch which implement for freelist to have another sized index
in according to nr objects.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2014-02-08 12:10:32 +02:00
H. Peter Anvin
a3b072cd18 * Avoid WARN_ON() when mapping BGRT on Baytrail (EFI 32-bit).
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Merge tag 'efi-urgent' into x86/urgent

 * Avoid WARN_ON() when mapping BGRT on Baytrail (EFI 32-bit).

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-02-07 11:27:30 -08:00
KOSAKI Motohiro
a85d9df1ea mm: __set_page_dirty_nobuffers() uses spin_lock_irqsave() instead of spin_lock_irq()
During aio stress test, we observed the following lockdep warning.  This
mean AIO+numa_balancing is currently deadlockable.

The problem is, aio_migratepage disable interrupt, but
__set_page_dirty_nobuffers unintentionally enable it again.

Generally, all helper function should use spin_lock_irqsave() instead of
spin_lock_irq() because they don't know caller at all.

   other info that might help us debug this:
    Possible unsafe locking scenario:

          CPU0
          ----
     lock(&(&ctx->completion_lock)->rlock);
     <Interrupt>
       lock(&(&ctx->completion_lock)->rlock);

    *** DEADLOCK ***

      dump_stack+0x19/0x1b
      print_usage_bug+0x1f7/0x208
      mark_lock+0x21d/0x2a0
      mark_held_locks+0xb9/0x140
      trace_hardirqs_on_caller+0x105/0x1d0
      trace_hardirqs_on+0xd/0x10
      _raw_spin_unlock_irq+0x2c/0x50
      __set_page_dirty_nobuffers+0x8c/0xf0
      migrate_page_copy+0x434/0x540
      aio_migratepage+0xb1/0x140
      move_to_new_page+0x7d/0x230
      migrate_pages+0x5e5/0x700
      migrate_misplaced_page+0xbc/0xf0
      do_numa_page+0x102/0x190
      handle_pte_fault+0x241/0x970
      handle_mm_fault+0x265/0x370
      __do_page_fault+0x172/0x5a0
      do_page_fault+0x1a/0x70
      page_fault+0x28/0x30

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-06 13:48:51 -08:00
Weijie Yang
f893ab41e4 mm/swap: fix race on swap_info reuse between swapoff and swapon
swapoff clear swap_info's SWP_USED flag prematurely and free its
resources after that.  A concurrent swapon will reuse this swap_info
while its previous resources are not cleared completely.

These late freed resources are:
 - p->percpu_cluster
 - swap_cgroup_ctrl[type]
 - block_device setting
 - inode->i_flags &= ~S_SWAPFILE

This patch clears the SWP_USED flag after all its resources are freed,
so that swapon can reuse this swap_info by alloc_swap_info() safely.

[akpm@linux-foundation.org: tidy up code comment]
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-06 13:48:51 -08:00
Shaohua Li
579f82901f swap: add a simple detector for inappropriate swapin readahead
This is a patch to improve swap readahead algorithm.  It's from Hugh and
I slightly changed it.

Hugh's original changelog:

swapin readahead does a blind readahead, whether or not the swapin is
sequential.  This may be ok on harddisk, because large reads have
relatively small costs, and if the readahead pages are unneeded they can
be reclaimed easily - though, what if their allocation forced reclaim of
useful pages? But on SSD devices large reads are more expensive than
small ones: if the readahead pages are unneeded, reading them in caused
significant overhead.

This patch adds very simplistic random read detection.  Stealing the
PageReadahead technique from Konstantin Khlebnikov's patch, avoiding the
vma/anon_vma sophistications of Shaohua Li's patch, swapin_nr_pages()
simply looks at readahead's current success rate, and narrows or widens
its readahead window accordingly.  There is little science to its
heuristic: it's about as stupid as can be whilst remaining effective.

The table below shows elapsed times (in centiseconds) when running a
single repetitive swapping load across a 1000MB mapping in 900MB ram
with 1GB swap (the harddisk tests had taken painfully too long when I
used mem=500M, but SSD shows similar results for that).

Vanilla is the 3.6-rc7 kernel on which I started; Shaohua denotes his
Sep 3 patch in mmotm and linux-next; HughOld denotes my Oct 1 patch
which Shaohua showed to be defective; HughNew this Nov 14 patch, with
page_cluster as usual at default of 3 (8-page reads); HughPC4 this same
patch with page_cluster 4 (16-page reads); HughPC0 with page_cluster 0
(1-page reads: no readahead).

HDD for swapping to harddisk, SSD for swapping to VertexII SSD.  Seq for
sequential access to the mapping, cycling five times around; Rand for
the same number of random touches.  Anon for a MAP_PRIVATE anon mapping;
Shmem for a MAP_SHARED anon mapping, equivalent to tmpfs.

One weakness of Shaohua's vma/anon_vma approach was that it did not
optimize Shmem: seen below.  Konstantin's approach was perhaps mistuned,
50% slower on Seq: did not compete and is not shown below.

HDD        Vanilla Shaohua HughOld HughNew HughPC4 HughPC0
Seq Anon     73921   76210   75611   76904   78191  121542
Seq Shmem    73601   73176   73855   72947   74543  118322
Rand Anon   895392  831243  871569  845197  846496  841680
Rand Shmem 1058375 1053486  827935  764955  764376  756489

SSD        Vanilla Shaohua HughOld HughNew HughPC4 HughPC0
Seq Anon     24634   24198   24673   25107   21614   70018
Seq Shmem    24959   24932   25052   25703   22030   69678
Rand Anon    43014   26146   28075   25989   26935   25901
Rand Shmem   45349   45215   28249   24268   24138   24332

These tests are, of course, two extremes of a very simple case: under
heavier mixed loads I've not yet observed any consistent improvement or
degradation, and wider testing would be welcome.

Shaohua Li:

Test shows Vanilla is slightly better in sequential workload than Hugh's
patch.  I observed with Hugh's patch sometimes the readahead size is
shrinked too fast (from 8 to 1 immediately) in sequential workload if
there is no hit.  And in such case, continuing doing readahead is good
actually.

I don't prepare a sophisticated algorithm for the sequential workload
because so far we can't guarantee sequential accessed pages are swap out
sequentially.  So I slightly change Hugh's heuristic - don't shrink
readahead size too fast.

Here is my test result (unit second, 3 runs average):
	Vanilla		Hugh		New
Seq	356		370		360
Random	4525		2447		2444

Attached graph is the swapin/swapout throughput I collected with 'vmstat
2'.  The first part is running a random workload (till around 1200 of
the x-axis) and the second part is running a sequential workload.
swapin and swapout throughput are almost identical in steady state in
both workloads.  These are expected behavior.  while in Vanilla, swapin
is much bigger than swapout especially in random workload (because wrong
readahead).

Original patches by: Shaohua Li and Konstantin Khlebnikov.

[fengguang.wu@intel.com: swapin_nr_pages() can be static]
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-06 13:48:51 -08:00
Tejun Heo
1ff6bbfd13 arm, pm, vmpressure: add missing slab.h includes
arch/arm/mach-tegra/pm.c, kernel/power/console.c and mm/vmpressure.c
were somehow getting slab.h indirectly through cgroup.h which in turn
was getting it indirectly through xattr.h.  A scheduled cgroup change
drops xattr.h inclusion from cgroup.h and breaks compilation of these
three files.  Add explicit slab.h includes to the three files.

A pending cgroup patch depends on this change and it'd be great if
this can be routed through cgroup/for-3.14-fixes branch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-tegra@vger.kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: cgroups@vger.kernel.org
2014-02-03 13:24:01 -05:00
Linus Torvalds
7b383bef25 Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
Pull SLAB changes from Pekka Enberg:
 "Random bug fixes that have accumulated in my inbox over the past few
  months"

* 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
  mm: Fix warning on make htmldocs caused by slab.c
  mm: slub: work around unneeded lockdep warning
  mm: sl[uo]b: fix misleading comments
  slub: Fix possible format string bug.
  slub: use lockdep_assert_held
  slub: Fix calculation of cpu slabs
  slab.h: remove duplicate kmalloc declaration and fix kernel-doc warnings
2014-02-02 11:30:08 -08:00
Ingo Molnar
eaa4e4fcf1 Merge branch 'linus' into sched/core, to resolve conflicts
Conflicts:
	kernel/sysctl.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-02 09:45:39 +01:00
Masanari Iida
cb8ee1a3d4 mm: Fix warning on make htmldocs caused by slab.c
This patch fixed following errors while make htmldocs
Warning(/mm/slab.c:1956): No description found for parameter 'page'
Warning(/mm/slab.c:1956): Excess function parameter 'slabp' description in 'slab_destroy'

Incorrect function parameter "slabp" was set instead of "page"

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2014-01-31 13:52:25 +02:00
Dave Hansen
67b6c900dc mm: slub: work around unneeded lockdep warning
The slub code does some setup during early boot in
early_kmem_cache_node_alloc() with some local data.  There is no
possible way that another CPU can see this data, so the slub code
doesn't unnecessarily lock it.  However, some new lockdep asserts
check to make sure that add_partial() _always_ has the list_lock
held.

Just add the locking, even though it is technically unnecessary.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2014-01-31 13:41:26 +02:00
Vladimir Davydov
7c094fd698 memcg: fix mutex not unlocked on memcg_create_kmem_cache fail path
Commit 842e2873697e ("memcg: get rid of kmem_cache_dup()") introduced a
mutex for memcg_create_kmem_cache() to protect the tmp_name buffer that
holds the memcg name.  It failed to unlock the mutex if this buffer
could not be allocated.

This patch fixes the issue by appropriately unlocking the mutex if the
allocation fails.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Glauber Costa <glommer@parallels.com>
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>
2014-01-30 16:56:56 -08:00
David Rientjes
778c14affa mm, oom: base root bonus on current usage
A 3% of system memory bonus is sometimes too excessive in comparison to
other processes.

With commit a63d83f427fb ("oom: badness heuristic rewrite"), the OOM
killer tries to avoid killing privileged tasks by subtracting 3% of
overall memory (system or cgroup) from their per-task consumption.  But
as a result, all root tasks that consume less than 3% of overall memory
are considered equal, and so it only takes 33+ privileged tasks pushing
the system out of memory for the OOM killer to do something stupid and
kill dhclient or other root-owned processes.  For example, on a 32G
machine it can't tell the difference between the 1M agetty and the 10G
fork bomb member.

The changelog describes this 3% boost as the equivalent to the global
overcommit limit being 3% higher for privileged tasks, but this is not
the same as discounting 3% of overall memory from _every privileged task
individually_ during OOM selection.

Replace the 3% of system memory bonus with a 3% of current memory usage
bonus.

By giving root tasks a bonus that is proportional to their actual size,
they remain comparable even when relatively small.  In the example
above, the OOM killer will discount the 1M agetty's 256 badness points
down to 179, and the 10G fork bomb's 262144 points down to 183500 points
and make the right choice, instead of discounting both to 0 and killing
agetty because it's first in the task list.

Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30 16:56:56 -08:00
Dave Hansen
a03208652d mm/slub.c: fix page->_count corruption (again)
Commit abca7c496584 ("mm: fix slab->page _count corruption when using
slub") notes that we can not _set_ a page->counters directly, except
when using a real double-cmpxchg.  Doing so can lose updates to
->_count.

That is an absolute rule:

        You may not *set* page->counters except via a cmpxchg.

Commit abca7c496584 fixed this for the folks who have the slub
cmpxchg_double code turned off at compile time, but it left the bad case
alone.  It can still be reached, and the same bug triggered in two
cases:

1. Turning on slub debugging at runtime, which is available on
   the distro kernels that I looked at.
2. On 64-bit CPUs with no CMPXCHG16B (some early AMD x86-64
   cpus, evidently)

There are at least 3 ways we could fix this:

1. Take all of the exising calls to cmpxchg_double_slab() and
   __cmpxchg_double_slab() and convert them to take an old, new
   and target 'struct page'.
2. Do (1), but with the newly-introduced 'slub_data'.
3. Do some magic inside the two cmpxchg...slab() functions to
   pull the counters out of new_counters and only set those
   fields in page->{inuse,frozen,objects}.

I've done (2) as well, but it's a bunch more code.  This patch is an
attempt at (3).  This was the most straightforward and foolproof way
that I could think to do this.

This would also technically allow us to get rid of the ugly

#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
       defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)

in 'struct page', but leaving it alone has the added benefit that
'counters' stays 'unsigned' instead of 'unsigned long', so all the
copies that the slub code does stay a bit smaller.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30 16:56:56 -08:00
David Rientjes
8790c71a18 mm/mempolicy.c: fix mempolicy printing in numa_maps
As a result of commit 5606e3877ad8 ("mm: numa: Migrate on reference
policy"), /proc/<pid>/numa_maps prints the mempolicy for any <pid> as
"prefer:N" for the local node, N, of the process reading the file.

This should only be printed when the mempolicy of <pid> is
MPOL_PREFERRED for node N.

If the process is actually only using the default mempolicy for local
node allocation, make sure "default" is printed as expected.

Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Robert Lippert <rlippert@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>	[3.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30 16:56:56 -08:00
Minchan Kim
31fc00bb78 zsmalloc: add copyright
Add my copyright to the zsmalloc source code which I maintain.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30 16:56:55 -08:00
Minchan Kim
bcf1647d08 zsmalloc: move it under mm
This patch moves zsmalloc under mm directory.

Before that, description will explain why we have needed custom
allocator.

Zsmalloc is a new slab-based memory allocator for storing compressed
pages.  It is designed for low fragmentation and high allocation success
rate on large object, but <= PAGE_SIZE allocations.

zsmalloc differs from the kernel slab allocator in two primary ways to
achieve these design goals.

zsmalloc never requires high order page allocations to back slabs, or
"size classes" in zsmalloc terms.  Instead it allows multiple
single-order pages to be stitched together into a "zspage" which backs
the slab.  This allows for higher allocation success rate under memory
pressure.

Also, zsmalloc allows objects to span page boundaries within the zspage.
This allows for lower fragmentation than could be had with the kernel
slab allocator for objects between PAGE_SIZE/2 and PAGE_SIZE.  With the
kernel slab allocator, if a page compresses to 60% of it original size,
the memory savings gained through compression is lost in fragmentation
because another object of the same size can't be stored in the leftover
space.

This ability to span pages results in zsmalloc allocations not being
directly addressable by the user.  The user is given an
non-dereferencable handle in response to an allocation request.  That
handle must be mapped, using zs_map_object(), which returns a pointer to
the mapped region that can be used.  The mapping is necessary since the
object data may reside in two different noncontigious pages.

The zsmalloc fulfills the allocation needs for zram perfectly

[sjenning@linux.vnet.ibm.com: borrow Seth's quote]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30 16:56:55 -08:00
Linus Torvalds
f568849eda Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block
Pull core block IO changes from Jens Axboe:
 "The major piece in here is the immutable bio_ve series from Kent, the
  rest is fairly minor.  It was supposed to go in last round, but
  various issues pushed it to this release instead.  The pull request
  contains:

   - Various smaller blk-mq fixes from different folks.  Nothing major
     here, just minor fixes and cleanups.

   - Fix for a memory leak in the error path in the block ioctl code
     from Christian Engelmayer.

   - Header export fix from CaiZhiyong.

   - Finally the immutable biovec changes from Kent Overstreet.  This
     enables some nice future work on making arbitrarily sized bios
     possible, and splitting more efficient.  Related fixes to immutable
     bio_vecs:

        - dm-cache immutable fixup from Mike Snitzer.
        - btrfs immutable fixup from Muthu Kumar.

  - bio-integrity fix from Nic Bellinger, which is also going to stable"

* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
  xtensa: fixup simdisk driver to work with immutable bio_vecs
  block/blk-mq-cpu.c: use hotcpu_notifier()
  blk-mq: for_each_* macro correctness
  block: Fix memory leak in rw_copy_check_uvector() handling
  bio-integrity: Fix bio_integrity_verify segment start bug
  block: remove unrelated header files and export symbol
  blk-mq: uses page->list incorrectly
  blk-mq: use __smp_call_function_single directly
  btrfs: fix missing increment of bi_remaining
  Revert "block: Warn and free bio if bi_end_io is not set"
  block: Warn and free bio if bi_end_io is not set
  blk-mq: fix initializing request's start time
  block: blk-mq: don't export blk_mq_free_queue()
  block: blk-mq: make blk_sync_queue support mq
  block: blk-mq: support draining mq queue
  dm cache: increment bi_remaining when bi_end_io is restored
  block: fixup for generic bio chaining
  block: Really silence spurious compiler warnings
  block: Silence spurious compiler warnings
  block: Kill bio_pair_split()
  ...
2014-01-30 11:19:05 -08:00
Yinghai Lu
f544e14f3e memblock: add limit checking to memblock_virt_alloc
In original bootmem wrapper for memblock, we have limit checking.

Add it to memblock_virt_alloc, to address arm and x86 booting crash.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Reported-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Reported-by: Olof Johansson <olof@lixom.net>
Tested-by: Olof Johansson <olof@lixom.net>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: "Strashko, Grygorii" <grygorii.strashko@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29 16:22:40 -08:00
Mark Rutland
58d5640ebd mm/readahead.c: fix do_readahead() for no readpage(s)
Commit 63d0f0a3c7e1 ("mm/readahead.c:do_readhead(): don't check for
->readpage") unintentionally made do_readahead return 0 for all valid
files regardless of whether readahead was supported, rather than the
expected -EINVAL.  This gets forwarded on to userspace, and results in
sys_readahead appearing to succeed in cases that don't make sense (e.g.
when called on pipes or sockets).  This issue is detected by the LTP
readahead01 testcase.

As the exact return value of force_page_cache_readahead is currently
never used, we can simplify it to return only 0 or -EINVAL (when
readpage or readpages is missing).  With that in place we can simply
forward on the return value of force_page_cache_readahead in
do_readahead.

This patch performs said change, restoring the expected semantics.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29 16:22:40 -08:00
Dave Hansen
a0132ac0f2 mm/slub.c: do not VM_BUG_ON_PAGE() for temporary on-stack pages
Commit 309381feaee5 ("mm: dump page when hitting a VM_BUG_ON using
VM_BUG_ON_PAGE") added a bunch of VM_BUG_ON_PAGE() calls.

But, most of the ones in the slub code are for _temporary_ 'struct
page's which are declared on the stack and likely have lots of gunk in
them.  Dumping their contents out will just confuse folks looking at
bad_page() output.  Plus, if we try to page_to_pfn() on them or
soemthing, we'll probably oops anyway.

Turn them back in to VM_BUG_ON()s.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29 16:22:40 -08:00
Dave Jones
ba3253c78d slab: fix wrong retval on kmem_cache_create_memcg error path
On kmem_cache_create_memcg() error path we set 'err', but leave 's' (the
new cache ptr) undefined.  The latter can be NULL if we could not
allocate the cache, or pointing to a freed area if we failed somewhere
later while trying to initialize it.  Initially we checked 'err'
immediately before exiting the function and returned NULL if it was set
ignoring the value of 's':

    out_unlock:
        ...
        if (err) {
            /* report error */
            return NULL;
        }
        return s;

Recently this check was, in fact, broken by commit f717eb3abb5e ("slab:
do not panic if we fail to create memcg cache"), which turned it to:

    out_unlock:
        ...
        if (err && !memcg) {
            /* report error */
            return NULL;
        }
        return s;

As a result, if we are failing creating a cache for a memcg, we will
skip the check and return 's' that can contain crap.  Obviously, commit
f717eb3abb5e intended not to return crap on error allocating a cache for
a memcg, but only to remove the error reporting in this case, so the
check should look like this:

    out_unlock:
        ...
        if (err) {
            if (!memcg)
                return NULL;
            /* report error */
            return NULL;
        }
        return s;

[rientjes@google.com: despaghettification]
[vdavydov@parallels.com: patch monkeying]
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29 16:22:40 -08:00
Andrew Morton
4a404bea94 mm/mempolicy.c: convert to pr_foo()
A few printk(KERN_*'s have snuck in there.

Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29 16:22:39 -08:00
Mel Gorman
c297663c0b mm: numa: initialise numa balancing after jump label initialisation
The command line parsing takes place before jump labels are initialised
which generates a warning if numa_balancing= is specified and
CONFIG_JUMP_LABEL is set.

On older kernels before commit c4b2c0c5f647 ("static_key: WARN on usage
before jump_label_init was called") the kernel would have crashed.  This
patch enables automatic numa balancing later in the initialisation
process if numa_balancing= is specified.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29 16:22:39 -08:00
Johannes Weiner
a1c3bfb2f6 mm/page-writeback.c: do not count anon pages as dirtyable memory
The VM is currently heavily tuned to avoid swapping.  Whether that is
good or bad is a separate discussion, but as long as the VM won't swap
to make room for dirty cache, we can not consider anonymous pages when
calculating the amount of dirtyable memory, the baseline to which
dirty_background_ratio and dirty_ratio are applied.

A simple workload that occupies a significant size (40+%, depending on
memory layout, storage speeds etc.) of memory with anon/tmpfs pages and
uses the remainder for a streaming writer demonstrates this problem.  In
that case, the actual cache pages are a small fraction of what is
considered dirtyable overall, which results in an relatively large
portion of the cache pages to be dirtied.  As kswapd starts rotating
these, random tasks enter direct reclaim and stall on IO.

Only consider free pages and file pages dirtyable.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Tejun Heo <tj@kernel.org>
Tested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29 16:22:39 -08:00
Johannes Weiner
a804552b9a mm/page-writeback.c: fix dirty_balance_reserve subtraction from dirtyable memory
Tejun reported stuttering and latency spikes on a system where random
tasks would enter direct reclaim and get stuck on dirty pages.  Around
50% of memory was occupied by tmpfs backed by an SSD, and another disk
(rotating) was reading and writing at max speed to shrink a partition.

: The problem was pretty ridiculous.  It's a 8gig machine w/ one ssd and 10k
: rpm harddrive and I could reliably reproduce constant stuttering every
: several seconds for as long as buffered IO was going on on the hard drive
: either with tmpfs occupying somewhere above 4gig or a test program which
: allocates about the same amount of anon memory.  Although swap usage was
: zero, turning off swap also made the problem go away too.
:
: The trigger conditions seem quite plausible - high anon memory usage w/
: heavy buffered IO and swap configured - and it's highly likely that this
: is happening in the wild too.  (this can happen with copying large files
: to usb sticks too, right?)

This patch (of 2):

The dirty_balance_reserve is an approximation of the fraction of free
pages that the page allocator does not make available for page cache
allocations.  As a result, it has to be taken into account when
calculating the amount of "dirtyable memory", the baseline to which
dirty_background_ratio and dirty_ratio are applied.

However, currently the reserve is subtracted from the sum of free and
reclaimable pages, which is non-sensical and leads to erroneous results
when the system is dominated by unreclaimable pages and the
dirty_balance_reserve is bigger than free+reclaimable.  In that case, at
least the already allocated cache should be considered dirtyable.

Fix the calculation by subtracting the reserve from the amount of free
pages, then adding the reclaimable pages on top.

[akpm@linux-foundation.org: fix CONFIG_HIGHMEM build]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Tejun Heo <tj@kernel.org>
Tested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-29 16:22:39 -08:00
Linus Torvalds
bf3d846b78 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "Assorted stuff; the biggest pile here is Christoph's ACL series.  Plus
  assorted cleanups and fixes all over the place...

  There will be another pile later this week"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (43 commits)
  __dentry_path() fixes
  vfs: Remove second variable named error in __dentry_path
  vfs: Is mounted should be testing mnt_ns for NULL or error.
  Fix race when checking i_size on direct i/o read
  hfsplus: remove can_set_xattr
  nfsd: use get_acl and ->set_acl
  fs: remove generic_acl
  nfs: use generic posix ACL infrastructure for v3 Posix ACLs
  gfs2: use generic posix ACL infrastructure
  jfs: use generic posix ACL infrastructure
  xfs: use generic posix ACL infrastructure
  reiserfs: use generic posix ACL infrastructure
  ocfs2: use generic posix ACL infrastructure
  jffs2: use generic posix ACL infrastructure
  hfsplus: use generic posix ACL infrastructure
  f2fs: use generic posix ACL infrastructure
  ext2/3/4: use generic posix ACL infrastructure
  btrfs: use generic posix ACL infrastructure
  fs: make posix_acl_create more useful
  fs: make posix_acl_chmod more useful
  ...
2014-01-28 08:38:04 -08:00
Rik van Riel
10f3904271 sched/numa, mm: Use active_nodes nodemask to limit numa migrations
Use the active_nodes nodemask to make smarter decisions on NUMA migrations.

In order to maximize performance of workloads that do not fit in one NUMA
node, we want to satisfy the following criteria:

  1) keep private memory local to each thread

  2) avoid excessive NUMA migration of pages

  3) distribute shared memory across the active nodes, to
     maximize memory bandwidth available to the workload

This patch accomplishes that by implementing the following policy for
NUMA migrations:

  1) always migrate on a private fault

  2) never migrate to a node that is not in the set of active nodes
     for the numa_group

  3) always migrate from a node outside of the set of active nodes,
     to a node that is in that set

  4) within the set of active nodes in the numa_group, only migrate
     from a node with more NUMA page faults, to a node with fewer
     NUMA page faults, with a 25% margin to avoid ping-ponging

This results in most pages of a workload ending up on the actively
used nodes, with reduced ping-ponging of pages between those nodes.

Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-6-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-28 13:17:07 +01:00
Rik van Riel
52bf84aa20 sched/numa, mm: Remove p->numa_migrate_deferred
Excessive migration of pages can hurt the performance of workloads
that span multiple NUMA nodes.  However, it turns out that the
p->numa_migrate_deferred knob is a really big hammer, which does
reduce migration rates, but does not actually help performance.

Now that the second stage of the automatic numa balancing code
has stabilized, it is time to replace the simplistic migration
deferral code with something smarter.

Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-2-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-28 13:17:04 +01:00
Linus Torvalds
54c0a4b461 Merge branch 'akpm' (incoming from Andrew)
Merge misc updates from Andrew Morton:

 - a few hotfixes

 - dynamic-debug updates

 - ipc updates

 - various other sweepings off the factory floor

* akpm: (31 commits)
  firmware/google: drop 'select EFI' to avoid recursive dependency
  compat: fix sys_fanotify_mark
  checkpatch.pl: check for function declarations without arguments
  mm/migrate.c: fix setting of cpupid on page migration twice against normal page
  softirq: use const char * const for softirq_to_name, whitespace neatening
  softirq: convert printks to pr_<level>
  softirq: use ffs() in __do_softirq()
  kernel/kexec.c: use vscnprintf() instead of vsnprintf() in vmcoreinfo_append_str()
  splice: fix unexpected size truncation
  ipc: fix compat msgrcv with negative msgtyp
  ipc,msg: document barriers
  ipc: delete seq_max field in struct ipc_ids
  ipc: simplify sysvipc_proc_open() return
  ipc: remove useless return statement
  ipc: remove braces for single statements
  ipc: standardize code comments
  ipc: whitespace cleanup
  ipc: change kern_ipc_perm.deleted type to bool
  ipc: introduce ipc_valid_object() helper to sort out IPC_RMID races
  ipc/sem.c: avoid overflow of semop undo (semadj) value
  ...
2014-01-27 21:17:55 -08:00
Linus Torvalds
1b17366d69 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Ben Herrenschmidt:
 "So here's my next branch for powerpc.  A bit late as I was on vacation
  last week.  It's mostly the same stuff that was in next already, I
  just added two patches today which are the wiring up of lockref for
  powerpc, which for some reason fell through the cracks last time and
  is trivial.

  The highlights are, in addition to a bunch of bug fixes:

   - Reworked Machine Check handling on kernels running without a
     hypervisor (or acting as a hypervisor).  Provides hooks to handle
     some errors in real mode such as TLB errors, handle SLB errors,
     etc...

   - Support for retrieving memory error information from the service
     processor on IBM servers running without a hypervisor and routing
     them to the memory poison infrastructure.

   - _PAGE_NUMA support on server processors

   - 32-bit BookE relocatable kernel support

   - FSL e6500 hardware tablewalk support

   - A bunch of new/revived board support

   - FSL e6500 deeper idle states and altivec powerdown support

  You'll notice a generic mm change here, it has been acked by the
  relevant authorities and is a pre-req for our _PAGE_NUMA support"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (121 commits)
  powerpc: Implement arch_spin_is_locked() using arch_spin_value_unlocked()
  powerpc: Add support for the optimised lockref implementation
  powerpc/powernv: Call OPAL sync before kexec'ing
  powerpc/eeh: Escalate error on non-existing PE
  powerpc/eeh: Handle multiple EEH errors
  powerpc: Fix transactional FP/VMX/VSX unavailable handlers
  powerpc: Don't corrupt transactional state when using FP/VMX in kernel
  powerpc: Reclaim two unused thread_info flag bits
  powerpc: Fix races with irq_work
  Move precessing of MCE queued event out from syscall exit path.
  pseries/cpuidle: Remove redundant call to ppc64_runlatch_off() in cpu idle routines
  powerpc: Make add_system_ram_resources() __init
  powerpc: add SATA_MV to ppc64_defconfig
  powerpc/powernv: Increase candidate fw image size
  powerpc: Add debug checks to catch invalid cpu-to-node mappings
  powerpc: Fix the setup of CPU-to-Node mappings during CPU online
  powerpc/iommu: Don't detach device without IOMMU group
  powerpc/eeh: Hotplug improvement
  powerpc/eeh: Call opal_pci_reinit() on powernv for restoring config space
  powerpc/eeh: Add restore_config operation
  ...
2014-01-27 21:11:26 -08:00
Linus Torvalds
d12de1ef5e Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc mremap fix from Ben Herrenschmidt:
 "This is the patch that I had sent after -rc8 and which we decided to
  wait before merging.  It's based on a different tree than my -next
  branch (it needs some pre-reqs that were in -rc4 or so while my -next
  is based on -rc1) so I left it as a separate branch for your to pull.
  It's identical to the request I did 2 or 3 weeks back.

  This fixes crashes in mremap with THP on powerpc.

  The fix however requires a small change in the generic code.  It moves
  a condition into a helper we can override from the arch which is
  harmless, but it *also* slightly changes the order of the set_pmd and
  the withdraw & deposit, which should be fine according to Kirill (who
  wrote that code) but I agree -rc8 is a bit late...

  It was acked by Kirill and Andrew told me to just merge it via powerpc"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/thp: Fix crash on mremap
2014-01-27 21:03:39 -08:00
Wanpeng Li
a3978a5194 mm/migrate.c: fix setting of cpupid on page migration twice against normal page
Commit 7851a45cd3f6 ("mm: numa: Copy cpupid on page migration") copies
over the cpupid at page migration time.  It is unnecessary to set it
again in alloc_misplaced_dst_page().

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-27 21:02:40 -08:00
Hugh Dickins
e82cb95d62 mm: bring back /sys/kernel/mm
Commit da29bd36224b ("mm/mm_init.c: make creation of the mm_kobj happen
earlier than device_initcall") changed to pure_initcall(mm_sysfs_init).

That's too early: mm_sysfs_init() depends on core_initcall(ksysfs_init)
to have made the kernel_kobj directory "kernel" in which to create "mm".

Make it postcore_initcall(mm_sysfs_init).  We could use core_initcall(),
and depend upon Makefile link order kernel/ mm/ fs/ ipc/ security/ ...
as core_initcall(debugfs_init) and core_initcall(securityfs_init) do;
but better not.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-27 21:02:39 -08:00
malc
add688fbd3 Revert "mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page}"
Revert commit ece86e222db4, which was intended as a small performance
improvement.

Despite the claim that the patch doesn't introduce any functional
changes in fact it does.

The "no page" path behaves different now.  Originally, vmalloc_to_page
might return NULL under some conditions, with new implementation it
returns pfn_to_page(0) which is not the same as NULL.

Simple test shows the difference.

test.c

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>

int __init myi(void)
{
	struct page *p;
	void *v;

	v = vmalloc(PAGE_SIZE);
	/* trigger the "no page" path in vmalloc_to_page*/
	vfree(v);

	p = vmalloc_to_page(v);

	pr_err("expected val = NULL, returned val = %p", p);

	return -EBUSY;
}

void __exit mye(void)
{

}
module_init(myi)
module_exit(mye)

Before interchange:
expected val = NULL, returned val =   (null)

After interchange:
expected val = NULL, returned val = c7ebe000

Signed-off-by: Vladimir Murzin <murzin.v@gmail.com>
Cc: Jianyu Zhan <nasa4836@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-27 21:02:39 -08:00
Yinghai Lu
fb5bb60cd0 memblock: don't silently align size in memblock_virt_alloc()
In original __alloc_memory_core_early() for bootmem wrapper, we do not
align size silently.

We should not do that, as later free with old size will leave some range
not freed.

It's obvious that code is copied from memblock_base_nid(), and that code
is wrong for the same reason.

Also remove that in memblock_alloc_base.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-27 21:02:39 -08:00
Steven Whitehouse
9fe55eea7e Fix race when checking i_size on direct i/o read
So far I've had one ACK for this, and no other comments. So I think it
is probably time to send this via some suitable tree. I'm guessing that
the vfs tree would be the most appropriate route, but not sure that
there is one at the moment (don't see anything recent at kernel.org)
so in that case I think -mm is the "back up plan". Al, please let me
know if you will take this?

Steve.

---------------------

Following on from the "Re: [PATCH v3] vfs: fix a bug when we do some dio
reads with append dio writes" thread on linux-fsdevel, this patch is my
current version of the fix proposed as option (b) in that thread.

Removing the i_size test from the direct i/o read path at vfs level
means that filesystems now have to deal with requests which are beyond
i_size themselves. These I've divided into three sets:

 a) Those with "no op" ->direct_IO (9p, cifs, ceph)
These are obviously not going to be an issue

 b) Those with "home brew" ->direct_IO (nfs, fuse)
I've been told that NFS should not have any problem with the larger
i_size, however I've added an extra test to FUSE to duplicate the
original behaviour just to be on the safe side.

 c) Those using __blockdev_direct_IO()
These call through to ->get_block() which should deal with the EOF
condition correctly. I've verified that with GFS2 and I believe that
Zheng has verified it for ext4. I've also run the test on XFS and it
passes both before and after this change.

The part of the patch in filemap.c looks a lot larger than it really is
- there are only two lines of real change. The rest is just indentation
of the contained code.

There remains a test of i_size though, which was added for btrfs. It
doesn't cause the other filesystems a problem as the test is performed
after ->direct_IO has been called. It is possible that there is a race
that does matter to btrfs, however this patch doesn't change that, so
its still an overall improvement.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reported-by: Zheng Liu <gnehzuil.liu@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-26 08:26:42 -05:00
Christoph Hellwig
feda821e76 fs: remove generic_acl
And instead convert tmpfs to use the new generic ACL code, with two stub
methods provided for in-memory filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-26 08:26:40 -05:00
Ingo Molnar
2b45e0f9f3 Merge branch 'linus' into x86/urgent
Merge in the x86 changes to apply a fix.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-25 09:16:14 +01:00
Mel Gorman
ec65993443 mm, x86: Account for TLB flushes only when debugging
Bisection between 3.11 and 3.12 fingered commit 9824cf97 ("mm:
vmstats: tlb flush counters") to cause overhead problems.

The counters are undeniably useful but how often do we really
need to debug TLB flush related issues?  It does not justify
taking the penalty everywhere so make it a debugging option.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-XzxjntugxuwpxXhcrxqqh53b@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-25 09:10:41 +01:00
Cyrill Gorcunov
34228d473e mm: ignore VM_SOFTDIRTY on VMA merging
The VM_SOFTDIRTY bit affects vma merge routine: if two VMAs has all bits
in vm_flags matched except dirty bit the kernel can't longer merge them
and this forces the kernel to generate new VMAs instead.

It finally may lead to the situation when userspace application reaches
vm.max_map_count limit and get crashed in worse case

 | (gimp:11768): GLib-ERROR **: gmem.c:110: failed to allocate 4096 bytes
 |
 | (file-tiff-load:12038): LibGimpBase-WARNING **: file-tiff-load: gimp_wire_read(): error
 | xinit: connection to X server lost
 |
 | waiting for X server to shut down
 | /usr/lib64/gimp/2.0/plug-ins/file-tiff-load terminated: Hangup
 | /usr/lib64/gimp/2.0/plug-ins/script-fu terminated: Hangup
 | /usr/lib64/gimp/2.0/plug-ins/script-fu terminated: Hangup

  https://bugzilla.kernel.org/show_bug.cgi?id=67651
  https://bugzilla.gnome.org/show_bug.cgi?id=719619#c0

Initial problem came from missed VM_SOFTDIRTY in do_brk() routine but
even if we would set up VM_SOFTDIRTY here, there is still a way to
prevent VMAs from merging: one can call

 | echo 4 > /proc/$PID/clear_refs

and clear all VM_SOFTDIRTY over all VMAs presented in memory map, then
new do_brk() will try to extend old VMA and finds that dirty bit doesn't
match thus new VMA will be generated.

As discussed with Pavel, the right approach should be to ignore
VM_SOFTDIRTY bit when we're trying to merge VMAs and if merge successed
we mark extended VMA with dirty bit where needed.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reported-by: Bastian Hougaard <gnome@rvzt.net>
Reported-by: Mel Gorman <mgorman@suse.de>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:53 -08:00
Fengguang Wu
871beb8c31 mm/rmap: fix coccinelle warnings
mm/rmap.c:851:9-10: WARNING: return of 0/1 in function 'invalid_mkclean_vma' with return type bool

 Return statements in functions returning bool should use
 true/false instead of 1/0.

Generated by: coccinelle/misc/boolreturn.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:53 -08:00
Jamie Liu
a5998061da mm/swapfile.c: do not skip lowest_bit in scan_swap_map() scan loop
In the second half of scan_swap_map()'s scan loop, offset is set to
si->lowest_bit and then incremented before entering the loop for the
first time, causing si->swap_map[si->lowest_bit] to be skipped.

Signed-off-by: Jamie Liu <jamieliu@google.com>
Cc: Shaohua Li <shli@fusionio.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23 16:36:53 -08:00