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578129 commits

Author SHA1 Message Date
Joonsoo Kim 158e319bba mm/slab: clean up cache type determination
Current cache type determination code is open-code and looks not
understandable.  Following patch will introduce one more cache type and
it would make code more complex.  So, before it happens, this patch
abstracts these codes.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim 832a15d209 mm/slab: align cache size first before determination of OFF_SLAB candidate
Finding suitable OFF_SLAB candidate is more related to aligned cache
size rather than original size.  Same reasoning can be applied to the
debug pagealloc candidate.  So, this patch moves up alignment fixup to
proper position.  From that point, size is aligned so we can remove some
alignment fixups.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim 2e6b360216 mm/slab: put the freelist at the end of slab page
Currently, the freelist is at the front of slab page.  This requires
extra space to meet object alignment requirement.  If we put the
freelist at the end of a slab page, objects could start at page boundary
and will be at correct alignment.  This is possible because freelist has
no alignment constraint itself.

This gives us two benefits: It removes extra memory space for the
freelist alignment and remove complex calculation at cache
initialization step.  I can't think notable drawback here.

I mentioned that this would reduce extra memory space, but, this benefit
is rather theoretical because it can be applied to very few cases.
Following is the example cache type that can get benefit from this
change.

  size align num before after
    32    8  124  4100  4092
    64    8   63  4103  4095
    88    8   46  4102  4094
   272    8   15  4103  4095
   408    8   10  4098  4090
    32   16  124  4108  4092
    64   16   63  4111  4095
    32   32  124  4124  4092
    64   32   63  4127  4095
    96   32   42  4106  4074

before means whole size for objects and aligned freelist before applying
patch and after shows the result of this patch.

Since before is more than 4096, number of object should decrease and
memory waste happens.

Anyway, this patch removes complex calculation so looks beneficial to
me.

[akpm@linux-foundation.org: fix kerneldoc]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim 249247b6f8 mm/slab: remove object status buffer for DEBUG_SLAB_LEAK
Now, we don't use object status buffer in any setup. Remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim d31676dfde mm/slab: alternative implementation for DEBUG_SLAB_LEAK
DEBUG_SLAB_LEAK is a debug option.  It's current implementation requires
status buffer so we need more memory to use it.  And, it cause
kmem_cache initialization step more complex.

To remove this extra memory usage and to simplify initialization step,
this patch implement this feature with another way.

When user requests to get slab object owner information, it marks that
getting information is started.  And then, all free objects in caches
are flushed to corresponding slab page.  Now, we can distinguish all
freed object so we can know all allocated objects, too.  After
collecting slab object owner information on allocated objects, mark is
checked that there is no free during the processing.  If true, we can be
sure that our information is correct so information is returned to user.

Although this way is rather complex, it has two important benefits
mentioned above.  So, I think it is worth changing.

There is one drawback that it takes more time to get slab object owner
information but it is just a debug option so it doesn't matter at all.

To help review, this patch implements new way only.  Following patch
will remove useless code.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim 40b4413797 mm/slab: clean up DEBUG_PAGEALLOC processing code
Currently, open code for checking DEBUG_PAGEALLOC cache is spread to
some sites.  It makes code unreadable and hard to change.

This patch cleans up this code.  The following patch will change the
criteria for DEBUG_PAGEALLOC cache so this clean-up will help it, too.

[akpm@linux-foundation.org: fix build with CONFIG_DEBUG_PAGEALLOC=n]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim 40323278b5 mm/slab: use more appropriate condition check for debug_pagealloc
debug_pagealloc debugging is related to SLAB_POISON flag rather than
FORCED_DEBUG option, although FORCED_DEBUG option will enable
SLAB_POISON.  Fix it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim a307ebd468 mm/slab: activate debug_pagealloc in SLAB when it is actually enabled
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim 260b61dd46 mm/slab: remove the checks for slab implementation bug
Some of "#if DEBUG" are for reporting slab implementation bug rather
than user usecase bug.  It's not really needed because slab is stable
for a quite long time and it makes code too dirty.  This patch remove
it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim 6fb924304a mm/slab: remove useless structure define
It is obsolete so remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joonsoo Kim 12c61fe9b7 mm/slab: fix stale code comment
This patchset implements a new freed object management way, that is,
OBJFREELIST_SLAB.  Purpose of it is to reduce memory overhead in SLAB.

SLAB needs a array to manage freed objects in a slab.  If there is
leftover after objects are packed into a slab, we can use it as a
management array, and, in this case, there is no memory waste.  But, in
the other cases, we need to allocate extra memory for a management array
or utilize dedicated internal memory in a slab for it.  Both cases
causes memory waste so it's not good.

With this patchset, freed object itself can be used for a management
array.  So, memory waste could be reduced.  Detailed idea and numbers
are described in last patch's commit description.  Please refer it.

In fact, I tested another idea implementing OBJFREELIST_SLAB with
extendable linked array through another freed object.  It can remove
memory waste completely but it causes more computational overhead in
critical lock path and it seems that overhead outweigh benefit.  So,
this patchset doesn't include it.  I will attach prototype just for a
reference.

This patch (of 16):

We use freelist_idx_t type for free object management whose size would be
smaller than size of unsigned int.  Fix it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer 9f706d6820 mm: fix some spelling
Fix up trivial spelling errors, noticed while reading the code.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer ca25719551 mm: new API kfree_bulk() for SLAB+SLUB allocators
This patch introduce a new API call kfree_bulk() for bulk freeing memory
objects not bound to a single kmem_cache.

Christoph pointed out that it is possible to implement freeing of
objects, without knowing the kmem_cache pointer as that information is
available from the object's page->slab_cache.  Proposing to remove the
kmem_cache argument from the bulk free API.

Jesper demonstrated that these extra steps per object comes at a
performance cost.  It is only in the case CONFIG_MEMCG_KMEM is compiled
in and activated runtime that these steps are done anyhow.  The extra
cost is most visible for SLAB allocator, because the SLUB allocator does
the page lookup (virt_to_head_page()) anyhow.

Thus, the conclusion was to keep the kmem_cache free bulk API with a
kmem_cache pointer, but we can still implement a kfree_bulk() API fairly
easily.  Simply by handling if kmem_cache_free_bulk() gets called with a
kmem_cache NULL pointer.

This does increase the code size a bit, but implementing a separate
kfree_bulk() call would likely increase code size even more.

Below benchmarks cost of alloc+free (obj size 256 bytes) on CPU i7-4790K
@ 4.00GHz, no PREEMPT and CONFIG_MEMCG_KMEM=y.

Code size increase for SLAB:

 add/remove: 0/0 grow/shrink: 1/0 up/down: 74/0 (74)
 function                                     old     new   delta
 kmem_cache_free_bulk                         660     734     +74

SLAB fastpath: 87 cycles(tsc) 21.814
  sz - fallback             - kmem_cache_free_bulk - kfree_bulk
   1 - 103 cycles 25.878 ns -  41 cycles 10.498 ns - 81 cycles 20.312 ns
   2 -  94 cycles 23.673 ns -  26 cycles  6.682 ns - 42 cycles 10.649 ns
   3 -  92 cycles 23.181 ns -  21 cycles  5.325 ns - 39 cycles 9.950 ns
   4 -  90 cycles 22.727 ns -  18 cycles  4.673 ns - 26 cycles 6.693 ns
   8 -  89 cycles 22.270 ns -  14 cycles  3.664 ns - 23 cycles 5.835 ns
  16 -  88 cycles 22.038 ns -  14 cycles  3.503 ns - 22 cycles 5.543 ns
  30 -  89 cycles 22.284 ns -  13 cycles  3.310 ns - 20 cycles 5.197 ns
  32 -  88 cycles 22.249 ns -  13 cycles  3.420 ns - 20 cycles 5.166 ns
  34 -  88 cycles 22.224 ns -  14 cycles  3.643 ns - 20 cycles 5.170 ns
  48 -  88 cycles 22.088 ns -  14 cycles  3.507 ns - 20 cycles 5.203 ns
  64 -  88 cycles 22.063 ns -  13 cycles  3.428 ns - 20 cycles 5.152 ns
 128 -  89 cycles 22.483 ns -  15 cycles  3.891 ns - 23 cycles 5.885 ns
 158 -  89 cycles 22.381 ns -  15 cycles  3.779 ns - 22 cycles 5.548 ns
 250 -  91 cycles 22.798 ns -  16 cycles  4.152 ns - 23 cycles 5.967 ns

SLAB when enabling MEMCG_KMEM runtime:
 - kmemcg fastpath: 130 cycles(tsc) 32.684 ns (step:0)
 1 - 148 cycles 37.220 ns -  66 cycles 16.622 ns - 66 cycles 16.583 ns
 2 - 141 cycles 35.510 ns -  51 cycles 12.820 ns - 58 cycles 14.625 ns
 3 - 140 cycles 35.017 ns -  37 cycles 9.326 ns - 33 cycles 8.474 ns
 4 - 137 cycles 34.507 ns -  31 cycles 7.888 ns - 33 cycles 8.300 ns
 8 - 140 cycles 35.069 ns -  25 cycles 6.461 ns - 25 cycles 6.436 ns
 16 - 138 cycles 34.542 ns -  23 cycles 5.945 ns - 22 cycles 5.670 ns
 30 - 136 cycles 34.227 ns -  22 cycles 5.502 ns - 22 cycles 5.587 ns
 32 - 136 cycles 34.253 ns -  21 cycles 5.475 ns - 21 cycles 5.324 ns
 34 - 136 cycles 34.254 ns -  21 cycles 5.448 ns - 20 cycles 5.194 ns
 48 - 136 cycles 34.075 ns -  21 cycles 5.458 ns - 21 cycles 5.367 ns
 64 - 135 cycles 33.994 ns -  21 cycles 5.350 ns - 21 cycles 5.259 ns
 128 - 137 cycles 34.446 ns -  23 cycles 5.816 ns - 22 cycles 5.688 ns
 158 - 137 cycles 34.379 ns -  22 cycles 5.727 ns - 22 cycles 5.602 ns
 250 - 138 cycles 34.755 ns -  24 cycles 6.093 ns - 23 cycles 5.986 ns

Code size increase for SLUB:
 function                                     old     new   delta
 kmem_cache_free_bulk                         717     799     +82

SLUB benchmark:
 SLUB fastpath: 46 cycles(tsc) 11.691 ns (step:0)
  sz - fallback             - kmem_cache_free_bulk - kfree_bulk
   1 -  61 cycles 15.486 ns -  53 cycles 13.364 ns - 57 cycles 14.464 ns
   2 -  54 cycles 13.703 ns -  32 cycles  8.110 ns - 33 cycles 8.482 ns
   3 -  53 cycles 13.272 ns -  25 cycles  6.362 ns - 27 cycles 6.947 ns
   4 -  51 cycles 12.994 ns -  24 cycles  6.087 ns - 24 cycles 6.078 ns
   8 -  50 cycles 12.576 ns -  21 cycles  5.354 ns - 22 cycles 5.513 ns
  16 -  49 cycles 12.368 ns -  20 cycles  5.054 ns - 20 cycles 5.042 ns
  30 -  49 cycles 12.273 ns -  18 cycles  4.748 ns - 19 cycles 4.758 ns
  32 -  49 cycles 12.401 ns -  19 cycles  4.821 ns - 19 cycles 4.810 ns
  34 -  98 cycles 24.519 ns -  24 cycles  6.154 ns - 24 cycles 6.157 ns
  48 -  83 cycles 20.833 ns -  21 cycles  5.446 ns - 21 cycles 5.429 ns
  64 -  75 cycles 18.891 ns -  20 cycles  5.247 ns - 20 cycles 5.238 ns
 128 -  93 cycles 23.271 ns -  27 cycles  6.856 ns - 27 cycles 6.823 ns
 158 - 102 cycles 25.581 ns -  30 cycles  7.714 ns - 30 cycles 7.695 ns
 250 - 107 cycles 26.917 ns -  38 cycles  9.514 ns - 38 cycles 9.506 ns

SLUB when enabling MEMCG_KMEM runtime:
 - kmemcg fastpath: 71 cycles(tsc) 17.897 ns (step:0)
 1 - 85 cycles 21.484 ns -  78 cycles 19.569 ns - 75 cycles 18.938 ns
 2 - 81 cycles 20.363 ns -  45 cycles 11.258 ns - 44 cycles 11.076 ns
 3 - 78 cycles 19.709 ns -  33 cycles 8.354 ns - 32 cycles 8.044 ns
 4 - 77 cycles 19.430 ns -  28 cycles 7.216 ns - 28 cycles 7.003 ns
 8 - 101 cycles 25.288 ns -  23 cycles 5.849 ns - 23 cycles 5.787 ns
 16 - 76 cycles 19.148 ns -  20 cycles 5.162 ns - 20 cycles 5.081 ns
 30 - 76 cycles 19.067 ns -  19 cycles 4.868 ns - 19 cycles 4.821 ns
 32 - 76 cycles 19.052 ns -  19 cycles 4.857 ns - 19 cycles 4.815 ns
 34 - 121 cycles 30.291 ns -  25 cycles 6.333 ns - 25 cycles 6.268 ns
 48 - 108 cycles 27.111 ns -  21 cycles 5.498 ns - 21 cycles 5.458 ns
 64 - 100 cycles 25.164 ns -  20 cycles 5.242 ns - 20 cycles 5.229 ns
 128 - 155 cycles 38.976 ns -  27 cycles 6.886 ns - 27 cycles 6.892 ns
 158 - 132 cycles 33.034 ns -  30 cycles 7.711 ns - 30 cycles 7.728 ns
 250 - 130 cycles 32.612 ns -  38 cycles 9.560 ns - 38 cycles 9.549 ns

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer e6cdb58d1c slab: implement bulk free in SLAB allocator
This patch implements the free side of bulk API for the SLAB allocator
kmem_cache_free_bulk(), and concludes the implementation of optimized
bulk API for SLAB allocator.

Benchmarked[1] cost of alloc+free (obj size 256 bytes) on CPU i7-4790K @
4.00GHz, with no debug options, no PREEMPT and CONFIG_MEMCG_KMEM=y but
no active user of kmemcg.

SLAB single alloc+free cost: 87 cycles(tsc) 21.814 ns with this
optimized config.

bulk- Current fallback          - optimized SLAB bulk
  1 - 102 cycles(tsc) 25.747 ns - 41 cycles(tsc) 10.490 ns - improved 59.8%
  2 -  94 cycles(tsc) 23.546 ns - 26 cycles(tsc)  6.567 ns - improved 72.3%
  3 -  92 cycles(tsc) 23.127 ns - 20 cycles(tsc)  5.244 ns - improved 78.3%
  4 -  90 cycles(tsc) 22.663 ns - 18 cycles(tsc)  4.588 ns - improved 80.0%
  8 -  88 cycles(tsc) 22.242 ns - 14 cycles(tsc)  3.656 ns - improved 84.1%
 16 -  88 cycles(tsc) 22.010 ns - 13 cycles(tsc)  3.480 ns - improved 85.2%
 30 -  89 cycles(tsc) 22.305 ns - 13 cycles(tsc)  3.303 ns - improved 85.4%
 32 -  89 cycles(tsc) 22.277 ns - 13 cycles(tsc)  3.309 ns - improved 85.4%
 34 -  88 cycles(tsc) 22.246 ns - 13 cycles(tsc)  3.294 ns - improved 85.2%
 48 -  88 cycles(tsc) 22.121 ns - 13 cycles(tsc)  3.492 ns - improved 85.2%
 64 -  88 cycles(tsc) 22.052 ns - 13 cycles(tsc)  3.411 ns - improved 85.2%
128 -  89 cycles(tsc) 22.452 ns - 15 cycles(tsc)  3.841 ns - improved 83.1%
158 -  89 cycles(tsc) 22.403 ns - 14 cycles(tsc)  3.746 ns - improved 84.3%
250 -  91 cycles(tsc) 22.775 ns - 16 cycles(tsc)  4.111 ns - improved 82.4%

Notice it is not recommended to do very large bulk operation with
this bulk API, because local IRQs are disabled in this period.

[1] https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/mm/slab_bulk_test01.c

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer 7b0501dd6b slab: avoid running debug SLAB code with IRQs disabled for alloc_bulk
Move the call to cache_alloc_debugcheck_after() outside the IRQ disabled
section in kmem_cache_alloc_bulk().

When CONFIG_DEBUG_SLAB is disabled the compiler should remove this code.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer 2a777eac17 slab: implement bulk alloc in SLAB allocator
This patch implements the alloc side of bulk API for the SLAB allocator.

Further optimization are still possible by changing the call to
__do_cache_alloc() into something that can return multiple objects.
This optimization is left for later, given end results already show in
the area of 80% speedup.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer d5e3ed66d6 slab: use slab_post_alloc_hook in SLAB allocator shared with SLUB
Reviewers notice that the order in slab_post_alloc_hook() of
kmemcheck_slab_alloc() and kmemleak_alloc_recursive() gets swapped
compared to slab.c / SLAB allocator.

Also notice memset now occurs before calling kmemcheck_slab_alloc() and
kmemleak_alloc_recursive().

I assume this reordering of kmemcheck, kmemleak and memset is okay
because this is the order they are used by the SLUB allocator.

This patch completes the sharing of alloc_hook's between SLUB and SLAB.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer 0142eae3ae mm: kmemcheck skip object if slab allocation failed
In the SLAB allocator kmemcheck_slab_alloc() is guarded against being
called in case the object is NULL.  In SLUB allocator this NULL pointer
invocation can happen, which seems like an oversight.

Move the NULL pointer check into kmemcheck code (kmemcheck_slab_alloc)
so the check gets moved out of the fastpath, when not compiled with
CONFIG_KMEMCHECK.

This is a step towards sharing post_alloc_hook between SLUB and SLAB,
because slab_post_alloc_hook() does not perform this check before
calling kmemcheck_slab_alloc().

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer 011eceaf0a slab: use slab_pre_alloc_hook in SLAB allocator shared with SLUB
Deduplicate code in SLAB allocator functions slab_alloc() and
slab_alloc_node() by using the slab_pre_alloc_hook() call, which is now
shared between SLUB and SLAB.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer fab9963a69 mm: fault-inject take over bootstrap kmem_cache check
Remove the SLAB specific function slab_should_failslab(), by moving the
check against fault-injection for the bootstrap slab, into the shared
function should_failslab() (used by both SLAB and SLUB).

This is a step towards sharing alloc_hook's between SLUB and SLAB.

This bootstrap slab "kmem_cache" is used for allocating struct
kmem_cache objects to the allocator itself.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer 11c7aec2a9 mm/slab: move SLUB alloc hooks to common mm/slab.h
First step towards sharing alloc_hook's between SLUB and SLAB
allocators.  Move the SLUB allocators *_alloc_hook to the common
mm/slab.h for internal slab definitions.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jesper Dangaard Brouer 376bf125ac slub: clean up code for kmem cgroup support to kmem_cache_free_bulk
This change is primarily an attempt to make it easier to realize the
optimizations the compiler performs in-case CONFIG_MEMCG_KMEM is not
enabled.

Performance wise, even when CONFIG_MEMCG_KMEM is compiled in, the
overhead is zero.  This is because, as long as no process have enabled
kmem cgroups accounting, the assignment is replaced by asm-NOP
operations.  This is possible because memcg_kmem_enabled() uses a
static_key_false() construct.

It also helps readability as it avoid accessing the p[] array like:
p[size - 1] which "expose" that the array is processed backwards inside
helper function build_detached_freelist().

Lastly this also makes the code more robust, in error case like passing
NULL pointers in the array.  Which were previously handled before commit
033745189b ("slub: add missing kmem cgroup support to
kmem_cache_free_bulk").

Fixes: 033745189b ("slub: add missing kmem cgroup support to kmem_cache_free_bulk")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Arnd Bergmann dec63a4dec paride: make 'verbose' parameter an 'int' again
gcc-6.0 found an ancient bug in the paride driver, which had a
"module_param(verbose, bool, 0);" since before 2.6.12, but actually uses
it to accept '0', '1' or '2' as arguments:

  drivers/block/paride/pd.c: In function 'pd_init_dev_parms':
  drivers/block/paride/pd.c:298:29: warning: comparison of constant '1' with boolean expression is always false [-Wbool-compare]
   #define DBMSG(msg) ((verbose>1)?(msg):NULL)

In 2012, Rusty did a cleanup patch that also changed the type of the
variable to 'bool', which introduced what is now a gcc warning.

This changes the type back to 'int' and adapts the module_param() line
instead, so it should work as documented in case anyone ever cares about
running the ancient driver with debugging.

Fixes: 90ab5ee941 ("module_param: make bool parameters really bool (drivers & misc)")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Rusty Russell <rusty@rustcorp.com.au>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
San Mehat 0d9c51a6e1 block: partition: add partition specific uevent callbacks for partition info
This patch has been carried in the Android tree for quite some time and
is one of the few patches required to get a mainline kernel up and
running with an exsiting Android userspace.  So I wanted to submit it
for review and consideration if it should be merged.

For partitions, add new uevent parameters 'PARTN' which specifies the
partitions index in the table, and 'PARTNAME', which specifies PARTNAME
specifices the partition name of a partition device.

Android's userspace uses this for creating device node links from the
partition name and number, ie:

    /dev/block/platform/soc/by-name/system
or
    /dev/block/platform/soc/by-num/p1

One can see its usage here:
    https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#355
and
    https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#494

[john.stultz@linaro.org: dropped NPARTS and reworded commit message for context]
Signed-off-by: Dima Zavin <dima@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Rom Lemarchand <romlem@google.com>
Cc: Android Kernel Team <kernel-team@android.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: <harald@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jun Piao 8d67d3c244 ocfs2/dlm: fix a variable overflow problem in dlmdomain.c
In dlm_send_join_cancels(), node is defined with type unsigned int, but
initialized with -1, this will lead variable overflow.  Although this
won't cause any runtime problem, the code looks a little uncoordinated.

Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jiufei Xue 814ce69432 ocfs2: fix a tiny race that leads file system read-only
when o2hb detect a node down, it first set the dead node to recovery map
and create ocfs2rec which will replay journal for dead node.  o2hb
thread then call dlm_do_local_recovery_cleanup() to delete the lock for
dead node.  After the lock of dead node is gone, locks for other nodes
can be granted and may modify the meta data without replaying journal of
the dead node.  The detail is described as follows.

     N1                         N2                   N3(master)
modify the extent tree of
inode, and commit
dirty metadata to journal,
then goes down.
                                                 o2hb thread detects
                                                 N1 goes down, set
                                                 recovery map and
                                                 delete the lock of N1.

                                                 dlm_thread flush ast
                                                 for the lock of N2.
                        do not detect the death
                        of N1, so recovery map is
                        empty.

                        read inode from disk
                        without replaying
                        the journal of N1 and
                        modify the extent tree
                        of the inode that N1
                        had modified.
                                                 ocfs2rec recover the
                                                 journal of N1.
                                                 The modification of N2
                                                 is lost.

The modification of N1 and N2 are not serial, and it will lead to
read-only file system.  We can set recovery_waiting flag to the lock
resource after delete the lock for dead node to prevent other node from
getting the lock before dlm recovery.  After dlm recovery, the recovery
map on N2 is not empty, ocfs2_inode_lock_full_nested() will wait for ocfs2
recovery.

Signed-off-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei d277f33eda ocfs2/dlm: return EINVAL when the lockres on migration target is in DROPPING_REF state
If master migrate this lock resource to node when it happened to purge
it, a new lock resource will be created and inserted into hash list.  If
then master goes down, the lock resource being purged is recovered, so
there exist two lock resource with different owner.  So return error to
master if the lock resource is in DROPPING state, master will retry to
migrate this lock resource.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei 8c03439681 ocfs2/dlm: clear DROPPING_REF flag when the master goes down
If the master goes down after return in-progress for deref message.  The
lock resource on non-master node can not be purged.  Clear the
DROPPING_REF flag and recovery it.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei 842b90b624 ocfs2/dlm: return in progress if master can not clear the refmap bit right now
Master returns in-progress to non-master node when it can not clear the
refmap bit right now.  And non-master node will not purge the lock
resource until receiving deref done message.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei 60d663cb52 ocfs2/dlm: add DEREF_DONE message
This series of patches is to fix the dis-order issue of setting/clearing
refmap bit described below.

Node 1                               Node 2(master)
dlmlock
dlm_do_master_request
                                dlm_master_request_handler
                                -> dlm_lockres_set_refmap_bit
dlmlock succeed
dlmunlock succeed

dlm_purge_lockres
                                dlm_deref_handler
                                -> find lock resource is in
                                   DLM_LOCK_RES_SETREF_INPROG state,
                                   so dispatch a deref work
dlm_purge_lockres succeed.

call dlmlock again
dlm_do_master_request
                                dlm_master_request_handler
                                -> dlm_lockres_set_refmap_bit

                                deref work trigger, call
                                dlm_lockres_clear_refmap_bit
                                to clear Node 1 from refmap

                                dlm_purge_lockres succeed

dlm_send_remote_lock_request
                                return DLM_IVLOCKID because
                                the lockres is not exist
BUG if the lockres is $RECOVERY

This series of patches add a new message to keep the order of set and
clear.  Other nodes can purge the lock resource only after the refmap bit
on master is cleared.

This patch is to add DEREF_DONE message and corresponding handler.  Node
can purge the lock resource after receiving this message.  As a new
message is added, so increase the minor number of dlm protocol version.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joseph Qi 39b29af030 ocfs2/dlm: fix a typo in dlmcommon.h
Refer to cluster/tcp.h, NET_MAX_PAYLOAD_BYTES is a typo for
O2NET_MAX_PAYLOAD_BYTES.

Since currently DLM_MIG_LOCKRES_RESERVED is not actually used, it won't
cause any problem.  But we'd better correct it for further use.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
jiangyiwen bfd97a0320 ocfs2: use spinlock_irqsave() to downconvert lock in ocfs2_osb_dump()
Commit a75e9ccabd ("ocfs2: use spinlock irqsave for downconvert lock")
missed an unmodified place in ocfs2_osb_dump(), so it still exists a
deadlock scenario.

    ocfs2_wake_downconvert_thread
    ocfs2_rw_unlock
    ocfs2_dio_end_io
    dio_complete
    .....
    bio_endio
    req_bio_endio
    ....
    scsi_io_completion
    blk_done_softirq
    __do_softirq
    do_softirq
    irq_exit
    do_IRQ
    ocfs2_osb_dump
    cat /sys/kernel/debug/ocfs2/${uuid}/fs_state

This patch still uses spin_lock_irqsave() - replace spin_lock() to solve
this situation.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
jiangyiwen 4d548f61d6 ocfs2/cluster: replace the interrupt safe spinlocks with common ones
There actually no hardware or software interrupts in the context which
using o2hb_live_lock, so we don't need to worry about race conditions
caused by irq/softirq with spinlock held.  Turning off irq is not good
for system performance after all.  Just replace them with a non
interrupt safe function.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Sudip Mukherjee e928f35061 blackfin: define dummy pgprot_writecombine for !MMU
blackfin allmodconfig build fails with the error:

  ../sound/core/pcm_native.c: In function 'snd_pcm_lib_default_mmap':
  ../sound/core/pcm_native.c:3386:24: error: implicit declaration of function 'pgprot_writecombine' [-Werror=implicit-function-declaration]
     area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
                          ^
  ../sound/core/pcm_native.c:3386:22: error: incompatible types when assigning to type 'pgprot_t {aka struct <anonymous>}' from type 'int'
     area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
                        ^

When !MMU, asm-generic will not define default pgprot_writecombine, so
blackfin needs to define it by itself.

The patch idea is from commit 65b9ab888c ("arch/c6x/include/asm/pgtable.h:
define dummy pgprot_writecombine for !MMU")

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Cc: Steven Miao <realmz6@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Sudip Mukherjee 3701dc8151 m32r: mm: fix build warning
While building we are getting warnings:

  arch/m32r/mm/init.c:63:17: warning: unused variable 'low'
  arch/m32r/mm/init.c:62:17: warning: unused variable 'max_dma'

max_dma and low are only used if CONFIG_MMU is defined.  Lets declare
the variables inside the #ifdef.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Peter Zijlstra 25528213fe tags: Fix DEFINE_PER_CPU expansions
$ make tags
  GEN     tags
ctags: Warning: drivers/acpi/processor_idle.c:64: null expansion of name pattern "\1"
ctags: Warning: drivers/xen/events/events_2l.c:41: null expansion of name pattern "\1"
ctags: Warning: kernel/locking/lockdep.c:151: null expansion of name pattern "\1"
ctags: Warning: kernel/rcu/rcutorture.c:133: null expansion of name pattern "\1"
ctags: Warning: kernel/rcu/rcutorture.c:135: null expansion of name pattern "\1"
ctags: Warning: kernel/workqueue.c:323: null expansion of name pattern "\1"
ctags: Warning: net/ipv4/syncookies.c:53: null expansion of name pattern "\1"
ctags: Warning: net/ipv6/syncookies.c:44: null expansion of name pattern "\1"
ctags: Warning: net/rds/page.c:45: null expansion of name pattern "\1"

Which are all the result of the DEFINE_PER_CPU pattern:

  scripts/tags.sh:200:	'/\<DEFINE_PER_CPU([^,]*, *\([[:alnum:]_]*\)/\1/v/'
  scripts/tags.sh:201:	'/\<DEFINE_PER_CPU_SHARED_ALIGNED([^,]*, *\([[:alnum:]_]*\)/\1/v/'

The below cures them. All except the workqueue one are within reasonable
distance of the 80 char limit. TJ do you have any preference on how to
fix the wq one, or shall we just not care its too long?

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Geliang Tang e6fd1fb3b5 init/main.c: use list_for_each_entry()
Use list_for_each_entry() instead of list_for_each() to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
James Bottomley a7dee8f45f Merge branch 'fixes' into misc 2016-03-15 15:24:44 -07:00
Linus Torvalds 710d60cbf1 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu hotplug updates from Thomas Gleixner:
 "This is the first part of the ongoing cpu hotplug rework:

   - Initial implementation of the state machine

   - Runs all online and prepare down callbacks on the plugged cpu and
     not on some random processor

   - Replaces busy loop waiting with completions

   - Adds tracepoints so the states can be followed"

More detailed commentary on this work from an earlier email:
 "What's wrong with the current cpu hotplug infrastructure?

   - Asymmetry

     The hotplug notifier mechanism is asymmetric versus the bringup and
     teardown.  This is mostly caused by the notifier mechanism.

   - Largely undocumented dependencies

     While some notifiers use explicitely defined notifier priorities,
     we have quite some notifiers which use numerical priorities to
     express dependencies without any documentation why.

   - Control processor driven

     Most of the bringup/teardown of a cpu is driven by a control
     processor.  While it is understandable, that preperatory steps,
     like idle thread creation, memory allocation for and initialization
     of essential facilities needs to be done before a cpu can boot,
     there is no reason why everything else must run on a control
     processor.  Before this patch series, bringup looks like this:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu

       bring the rest up

   - All or nothing approach

     There is no way to do partial bringups.  That's something which is
     really desired because we waste e.g.  at boot substantial amount of
     time just busy waiting that the cpu comes to life.  That's stupid
     as we could very well do preparatory steps and the initial IPI for
     other cpus and then go back and do the necessary low level
     synchronization with the freshly booted cpu.

   - Minimal debuggability

     Due to the notifier based design, it's impossible to switch between
     two stages of the bringup/teardown back and forth in order to test
     the correctness.  So in many hotplug notifiers the cancel
     mechanisms are either not existant or completely untested.

   - Notifier [un]registering is tedious

     To [un]register notifiers we need to protect against hotplug at
     every callsite.  There is no mechanism that bringup/teardown
     callbacks are issued on the online cpus, so every caller needs to
     do it itself.  That also includes error rollback.

  What's the new design?

     The base of the new design is a symmetric state machine, where both
     the control processor and the booting/dying cpu execute a well
     defined set of states.  Each state is symmetric in the end, except
     for some well defined exceptions, and the bringup/teardown can be
     stopped and reversed at almost all states.

     So the bringup of a cpu will look like this in the future:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu

                                       bring itself up

     The synchronization step does not require the control cpu to wait.
     That mechanism can be done asynchronously via a worker or some
     other mechanism.

     The teardown can be made very similar, so that the dying cpu cleans
     up and brings itself down.  Cleanups which need to be done after
     the cpu is gone, can be scheduled asynchronously as well.

  There is a long way to this, as we need to refactor the notion when a
  cpu is available.  Today we set the cpu online right after it comes
  out of the low level bringup, which is not really correct.

  The proper mechanism is to set it to available, i.e. cpu local
  threads, like softirqd, hotplug thread etc. can be scheduled on that
  cpu, and once it finished all booting steps, it's set to online, so
  general workloads can be scheduled on it.  The reverse happens on
  teardown.  First thing to do is to forbid scheduling of general
  workloads, then teardown all the per cpu resources and finally shut it
  off completely.

  This patch series implements the basic infrastructure for this at the
  core level.  This includes the following:

   - Basic state machine implementation with well defined states, so
     ordering and prioritization can be expressed.

   - Interfaces to [un]register state callbacks

     This invokes the bringup/teardown callback on all online cpus with
     the proper protection in place and [un]installs the callbacks in
     the state machine array.

     For callbacks which have no particular ordering requirement we have
     a dynamic state space, so that drivers don't have to register an
     explicit hotplug state.

     If a callback fails, the code automatically does a rollback to the
     previous state.

   - Sysfs interface to drive the state machine to a particular step.

     This is only partially functional today.  Full functionality and
     therefor testability will be achieved once we converted all
     existing hotplug notifiers over to the new scheme.

   - Run all CPU_ONLINE/DOWN_PREPARE notifiers on the booting/dying
     processor:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu
       wait for boot
                                       bring itself up

                                       Signal completion to control cpu

     In a previous step of this work we've done a full tree mechanical
     conversion of all hotplug notifiers to the new scheme.  The balance
     is a net removal of about 4000 lines of code.

     This is not included in this series, as we decided to take a
     different approach.  Instead of mechanically converting everything
     over, we will do a proper overhaul of the usage sites one by one so
     they nicely fit into the symmetric callback scheme.

     I decided to do that after I looked at the ugliness of some of the
     converted sites and figured out that their hotplug mechanism is
     completely buggered anyway.  So there is no point to do a
     mechanical conversion first as we need to go through the usage
     sites one by one again in order to achieve a full symmetric and
     testable behaviour"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  cpu/hotplug: Document states better
  cpu/hotplug: Fix smpboot thread ordering
  cpu/hotplug: Remove redundant state check
  cpu/hotplug: Plug death reporting race
  rcu: Make CPU_DYING_IDLE an explicit call
  cpu/hotplug: Make wait for dead cpu completion based
  cpu/hotplug: Let upcoming cpu bring itself fully up
  arch/hotplug: Call into idle with a proper state
  cpu/hotplug: Move online calls to hotplugged cpu
  cpu/hotplug: Create hotplug threads
  cpu/hotplug: Split out the state walk into functions
  cpu/hotplug: Unpark smpboot threads from the state machine
  cpu/hotplug: Move scheduler cpu_online notifier to hotplug core
  cpu/hotplug: Implement setup/removal interface
  cpu/hotplug: Make target state writeable
  cpu/hotplug: Add sysfs state interface
  cpu/hotplug: Hand in target state to _cpu_up/down
  cpu/hotplug: Convert the hotplugged cpu work to a state machine
  cpu/hotplug: Convert to a state machine for the control processor
  cpu/hotplug: Add tracepoints
  ...
2016-03-15 13:50:29 -07:00
Linus Torvalds df2e37c814 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "The 4.6 pile of irq updates contains:

   - Support for IPI irqdomains to support proper integration of IPIs to
     and from coprocessors.  The first user of this new facility is
     MIPS.  The relevant MIPS patches come with the core to avoid merge
     ordering issues and have been acked by Ralf.

   - A new command line option to set the default interrupt affinity
     mask at boot time.

   - Support for some more new ARM and MIPS interrupt controllers:
     tango, alpine-msix and bcm6345-l1

   - Two small cleanups for x86/apic which we merged into irq/core to
     avoid yet another branch in x86 with two tiny commits.

   - The usual set of updates, cleanups in drivers/irqchip.  Mostly in
     the area of ARM-GIC, arada-37-xp and atmel chips.  Nothing
     outstanding here"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits)
  irqchip/irq-alpine-msi: Release the correct domain on error
  irqchip/mxs: Fix error check of of_io_request_and_map()
  irqchip/sunxi-nmi: Fix error check of of_io_request_and_map()
  genirq: Export IRQ functions for module use
  irqchip/gic/realview: Support more RealView DCC variants
  Documentation/bindings: Document the Alpine MSIX driver
  irqchip: Add the Alpine MSIX interrupt controller
  irqchip/gic-v3: Always return IRQ_SET_MASK_OK_DONE in gic_set_affinity
  irqchip/gic-v3-its: Mark its_init() and its children as __init
  irqchip/gic-v3: Remove gic_root_node variable from the ITS code
  irqchip/gic-v3: ACPI: Add redistributor support via GICC structures
  irqchip/gic-v3: Add ACPI support for GICv3/4 initialization
  irqchip/gic-v3: Refactor gic_of_init() for GICv3 driver
  x86/apic: Deinline _flat_send_IPI_mask, save ~150 bytes
  x86/apic: Deinline __default_send_IPI_*, save ~200 bytes
  dt-bindings: interrupt-controller: Add SoC-specific compatible string to Marvell ODMI
  irqchip/mips-gic: Add new DT property to reserve IPIs
  MIPS: Delete smp-gic.c
  MIPS: Make smp CMP, CPS and MT use the new generic IPI functions
  MIPS: Add generic SMP IPI support
  ...
2016-03-15 12:48:48 -07:00
Linus Torvalds 8a284c062e Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "The timer department delivers this time:

   - Support for cross clock domain timestamps in the core code plus a
     first user.  That allows more precise timestamping for PTP and
     later for audio and other peripherals.

     The ptp/e1000e patches have been acked by the relevant maintainers
     and are carried in the timer tree to avoid merge ordering issues.

   - Support for unregistering the current clocksource watchdog.  That
     lifts a limitation for switching clocksources which has been there
     from day 1

   - The usual pile of fixes and updates to the core and the drivers.
     Nothing outstanding and exciting"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
  time/timekeeping: Work around false positive GCC warning
  e1000e: Adds hardware supported cross timestamp on e1000e nic
  ptp: Add PTP_SYS_OFFSET_PRECISE for driver crosstimestamping
  x86/tsc: Always Running Timer (ART) correlated clocksource
  hrtimer: Revert CLOCK_MONOTONIC_RAW support
  time: Add history to cross timestamp interface supporting slower devices
  time: Add driver cross timestamp interface for higher precision time synchronization
  time: Remove duplicated code in ktime_get_raw_and_real()
  time: Add timekeeping snapshot code capturing system time and counter
  time: Add cycles to nanoseconds translation
  jiffies: Use CLOCKSOURCE_MASK instead of constant
  clocksource: Introduce clocksource_freq2mult()
  clockevents/drivers/exynos_mct: Implement ->set_state_oneshot_stopped()
  clockevents/drivers/arm_global_timer: Implement ->set_state_oneshot_stopped()
  clockevents/drivers/arm_arch_timer: Implement ->set_state_oneshot_stopped()
  clocksource/drivers/arm_global_timer: Register delay timer
  clocksource/drivers/lpc32xx: Support timer-based ARM delay
  clocksource/drivers/lpc32xx: Support periodic mode
  clocksource/drivers/lpc32xx: Don't use the prescaler counter for clockevents
  clocksource/drivers/rockchip: Add err handle for rk_timer_init
  ...
2016-03-15 12:13:56 -07:00
Linus Torvalds 208de21477 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Miscellaneous fixes, cleanups, restructuring.

   - RCU torture-test updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Export rcu_gp_is_normal()
  rcu: Remove rcu_user_hooks_switch
  rcu: Catch up rcu_report_qs_rdp() comment with reality
  rcu: Document unique-name limitation for DEFINE_STATIC_SRCU()
  rcu: Make rcu/tiny_plugin.h explicitly non-modular
  irq: Privatize irq_common_data::state_use_accessors
  RCU: Privatize rcu_node::lock
  sparse: Add __private to privatize members of structs
  rcu: Remove useless rcu_data_p when !PREEMPT_RCU
  rcutorture: Correct no-expedite console messages
  rcu: Set rdp->gpwrap when CPU is idle
  rcu: Stop treating in-kernel CPU-bound workloads as errors
  rcu: Update rcu_report_qs_rsp() comment
  rcu: Assign false instead of 0 for ->core_needs_qs
  rcutorture: Check for self-detected stalls
  rcutorture: Don't keep empty console.log.diags files
  rcutorture: Add checks for rcutorture writer starvation
2016-03-15 11:38:05 -07:00
Linus Torvalds ae465beeff Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 timer update from Ingo Molnar:
 "A single simplification of the x86 TSC code"

* 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsc: Use topology functions
2016-03-15 11:29:24 -07:00
Linus Torvalds 8ab84ef699 Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core platform updates from Ingo Molnar:
 "Intel Quark and Geode SoC platform updates"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform/intel/quark: Drop IMR lock bit support
  x86/platform/intel/mid: Remove dead code
  x86/platform: Make platform/geode/net5501.c explicitly non-modular
  x86/platform: Make platform/geode/alix.c explicitly non-modular
  x86/platform: Make platform/geode/geos.c explicitly non-modular
  x86/platform: Make platform/intel-quark/imr_selftest.c explicitly non-modular
  x86/platform: Make platform/intel-quark/imr.c explicitly non-modular
2016-03-15 11:20:44 -07:00
Linus Torvalds 13c76ad872 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Enable full ASLR randomization for 32-bit programs (Hector
     Marco-Gisbert)

   - Add initial minimal INVPCI support, to flush global mappings (Andy
     Lutomirski)

   - Add KASAN enhancements (Andrey Ryabinin)

   - Fix mmiotrace for huge pages (Karol Herbst)

   - ... misc cleanups and small enhancements"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/32: Enable full randomization on i386 and X86_32
  x86/mm/kmmio: Fix mmiotrace for hugepages
  x86/mm: Avoid premature success when changing page attributes
  x86/mm/ptdump: Remove paravirt_enabled()
  x86/mm: Fix INVPCID asm constraint
  x86/dmi: Switch dmi_remap() from ioremap() [uncached] to ioremap_cache()
  x86/mm: If INVPCID is available, use it to flush global mappings
  x86/mm: Add a 'noinvpcid' boot option to turn off INVPCID
  x86/mm: Add INVPCID helpers
  x86/kasan: Write protect kasan zero shadow
  x86/kasan: Clear kasan_zero_page after TLB flush
  x86/mm/numa: Check for failures in numa_clear_kernel_node_hotplug()
  x86/mm/numa: Clean up numa_clear_kernel_node_hotplug()
  x86/mm: Make kmap_prot into a #define
  x86/mm/32: Set NX in __supported_pte_mask before enabling paging
  x86/mm: Streamline and restore probe_memory_block_size()
2016-03-15 10:45:39 -07:00
Linus Torvalds 9cf8d6360c Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode updates from Ingo Molnar:
 "The biggest change in this cycle was the separation of the microcode
  loading mechanism from the initrd code plus the support of built-in
  microcode images.

  There were also lots cleanups and general restructuring (by Borislav
  Petkov)"

* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  x86/microcode/intel: Drop orig_sum from ext signature checksum
  x86/microcode/intel: Improve microcode sanity-checking error messages
  x86/microcode/intel: Merge two consecutive if-statements
  x86/microcode/intel: Get rid of DWSIZE
  x86/microcode/intel: Change checksum variables to u32
  x86/microcode: Use kmemdup() rather than duplicating its implementation
  x86/microcode: Remove unnecessary paravirt_enabled check
  x86/microcode: Document builtin microcode loading method
  x86/microcode/AMD: Issue microcode updated message later
  x86/microcode/intel: Cleanup get_matching_model_microcode()
  x86/microcode/intel: Remove unused arg of get_matching_model_microcode()
  x86/microcode/intel: Rename mc_saved_in_initrd
  x86/microcode/intel: Use *wrmsrl variants
  x86/microcode/intel: Cleanup apply_microcode_intel()
  x86/microcode/intel: Move the BUG_ON up and turn it into WARN_ON
  x86/microcode/intel: Rename mc_intel variable to mc
  x86/microcode/intel: Rename mc_saved_count to num_saved
  x86/microcode/intel: Rename local variables of type struct mc_saved_data
  x86/microcode/AMD: Drop redundant printk prefix
  x86/microcode: Issue update message only once
  ...
2016-03-15 10:39:22 -07:00
Linus Torvalds ecc026bff6 Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fpu updates from Ingo Molnar:
 "The biggest change in terms of impact is the changing of the FPU
  context switch model to 'eagerfpu' for all CPU types, via: commit
  58122bf1d8: "x86/fpu: Default eagerfpu=on on all CPUs"

  This makes all FPU saves and restores synchronous and makes the FPU
  code a lot more obvious to read.  In the next cycle, if this change is
  problem free, we'll remove the old lazy FPU restore code altogether.

  This change flushed out some old bugs, which should all be fixed by
  now, BYMMV"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Default eagerfpu=on on all CPUs
  x86/fpu: Speed up lazy FPU restores slightly
  x86/fpu: Fold fpu_copy() into fpu__copy()
  x86/fpu: Fix FNSAVE usage in eagerfpu mode
  x86/fpu: Fix math emulation in eager fpu mode
2016-03-15 10:23:56 -07:00
Linus Torvalds fa53c48939 Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 build update from Ingo Molnar:
 "A single adjustment of a defconfig value"

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/defconfigs/32: Set CONFIG_FRAME_WARN to the Kconfig default
2016-03-15 10:16:48 -07:00
Linus Torvalds 42576bee6e Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Ingo Molnar:
 "Early command line options parsing enhancements from Dave Hansen, plus
  minor cleanups and enhancements"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Remove unused 'is_big_kernel' variable
  x86/boot: Use proper array element type in memset() size calculation
  x86/boot: Pass in size to early cmdline parsing
  x86/boot: Simplify early command line parsing
  x86/boot: Fix early command-line parsing when partial word matches
  x86/boot: Fix early command-line parsing when matching at end
  x86/boot: Simplify kernel load address alignment check
  x86/boot: Micro-optimize reset_early_page_tables()
2016-03-15 10:02:25 -07:00
Linus Torvalds ba33ea811e Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
 "This is another big update. Main changes are:

   - lots of x86 system call (and other traps/exceptions) entry code
     enhancements.  In particular the complex parts of the 64-bit entry
     code have been migrated to C code as well, and a number of dusty
     corners have been refreshed.  (Andy Lutomirski)

   - vDSO special mapping robustification and general cleanups (Andy
     Lutomirski)

   - cpufeature refactoring, cleanups and speedups (Borislav Petkov)

   - lots of other changes ..."

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  x86/cpufeature: Enable new AVX-512 features
  x86/entry/traps: Show unhandled signal for i386 in do_trap()
  x86/entry: Call enter_from_user_mode() with IRQs off
  x86/entry/32: Change INT80 to be an interrupt gate
  x86/entry: Improve system call entry comments
  x86/entry: Remove TIF_SINGLESTEP entry work
  x86/entry/32: Add and check a stack canary for the SYSENTER stack
  x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup
  x86/entry: Only allocate space for tss_struct::SYSENTER_stack if needed
  x86/entry: Vastly simplify SYSENTER TF (single-step) handling
  x86/entry/traps: Clear DR6 early in do_debug() and improve the comment
  x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions
  x86/entry/32: Restore FLAGS on SYSEXIT
  x86/entry/32: Filter NT and speed up AC filtering in SYSENTER
  x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test
  selftests/x86: In syscall_nt, test NT|TF as well
  x86/asm-offsets: Remove PARAVIRT_enabled
  x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled
  uprobes: __create_xol_area() must nullify xol_mapping.fault
  x86/cpufeature: Create a new synthetic cpu capability for machine check recovery
  ...
2016-03-15 09:32:27 -07:00