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  1. 23 11月, 2015 1 次提交
    • J
      slab/slub: adjust kmem_cache_alloc_bulk API · 865762a8
      由 Jesper Dangaard Brouer 提交于 
      Adjust kmem_cache_alloc_bulk API before we have any real users.

Adjust API to return type 'int' instead of previously type 'bool'.  This
is done to allow future extension of the bulk alloc API.

A future extension could be to allow SLUB to stop at a page boundary, when
specified by a flag, and then return the number of objects.

The advantage of this approach, would make it easier to make bulk alloc
run without local IRQs disabled.  With an approach of cmpxchg "stealing"
the entire c->freelist or page->freelist.  To avoid overshooting we would
stop processing at a slab-page boundary.  Else we always end up returning
some objects at the cost of another cmpxchg.

To keep compatible with future users of this API linking against an older
kernel when using the new flag, we need to return the number of allocated
objects with this API change.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      865762a8
  3. 09 9月, 2015 1 次提交
    • V
      mm: rename alloc_pages_exact_node() to __alloc_pages_node() · 96db800f
      由 Vlastimil Babka 提交于 
      alloc_pages_exact_node() was introduced in commit 6484eb3e ("page
allocator: do not check NUMA node ID when the caller knows the node is
valid") as an optimized variant of alloc_pages_node(), that doesn't
fallback to current node for nid == NUMA_NO_NODE.  Unfortunately the
name of the function can easily suggest that the allocation is
restricted to the given node and fails otherwise.  In truth, the node is
only preferred, unless __GFP_THISNODE is passed among the gfp flags.

The misleading name has lead to mistakes in the past, see for example
commits 5265047a ("mm, thp: really limit transparent hugepage
allocation to local node") and b360edb4 ("mm, mempolicy:
migrate_to_node should only migrate to node").

Another issue with the name is that there's a family of
alloc_pages_exact*() functions where 'exact' means exact size (instead
of page order), which leads to more confusion.

To prevent further mistakes, this patch effectively renames
alloc_pages_exact_node() to __alloc_pages_node() to better convey that
it's an optimized variant of alloc_pages_node() not intended for general
usage.  Both functions get described in comments.

It has been also considered to really provide a convenience function for
allocations restricted to a node, but the major opinion seems to be that
__GFP_THISNODE already provides that functionality and we shouldn't
duplicate the API needlessly.  The number of users would be small
anyway.

Existing callers of alloc_pages_exact_node() are simply converted to
call __alloc_pages_node(), with the exception of sba_alloc_coherent()
which open-codes the check for NUMA_NO_NODE, so it is converted to use
alloc_pages_node() instead.  This means it no longer performs some
VM_BUG_ON checks, and since the current check for nid in
alloc_pages_node() uses a 'nid < 0' comparison (which includes
NUMA_NO_NODE), it may hide wrong values which would be previously
exposed.

Both differences will be rectified by the next patch.

To sum up, this patch makes no functional changes, except temporarily
hiding potentially buggy callers.  Restricting the checks in
alloc_pages_node() is left for the next patch which can in turn expose
more existing buggy callers.
Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NRobin Holt <robinmholt@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Cliff Whickman <cpw@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      96db800f
  5. 05 9月, 2015 1 次提交
    • C
      slab: infrastructure for bulk object allocation and freeing · 484748f0
      由 Christoph Lameter 提交于 
      Add the basic infrastructure for alloc/free operations on pointer arrays.
It includes a generic function in the common slab code that is used in
this infrastructure patch to create the unoptimized functionality for slab
bulk operations.

Allocators can then provide optimized allocation functions for situations
in which large numbers of objects are needed.  These optimization may
avoid taking locks repeatedly and bypass metadata creation if all objects
in slab pages can be used to provide the objects required.

Allocators can extend the skeletons provided and add their own code to the
bulk alloc and free functions.  They can keep the generic allocation and
freeing and just fall back to those if optimizations would not work (like
for example when debugging is on).
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      484748f0
  7. 15 4月, 2015 1 次提交
  9. 13 2月, 2015 1 次提交
    • V
      slub: make dead caches discard free slabs immediately · d6e0b7fa
      由 Vladimir Davydov 提交于 
      To speed up further allocations SLUB may store empty slabs in per cpu/node
partial lists instead of freeing them immediately.  This prevents per
memcg caches destruction, because kmem caches created for a memory cgroup
are only destroyed after the last page charged to the cgroup is freed.

To fix this issue, this patch resurrects approach first proposed in [1].
It forbids SLUB to cache empty slabs after the memory cgroup that the
cache belongs to was destroyed.  It is achieved by setting kmem_cache's
cpu_partial and min_partial constants to 0 and tuning put_cpu_partial() so
that it would drop frozen empty slabs immediately if cpu_partial = 0.

The runtime overhead is minimal.  From all the hot functions, we only
touch relatively cold put_cpu_partial(): we make it call
unfreeze_partials() after freezing a slab that belongs to an offline
memory cgroup.  Since slab freezing exists to avoid moving slabs from/to a
partial list on free/alloc, and there can't be allocations from dead
caches, it shouldn't cause any overhead.  We do have to disable preemption
for put_cpu_partial() to achieve that though.

The original patch was accepted well and even merged to the mm tree.
However, I decided to withdraw it due to changes happening to the memcg
core at that time.  I had an idea of introducing per-memcg shrinkers for
kmem caches, but now, as memcg has finally settled down, I do not see it
as an option, because SLUB shrinker would be too costly to call since SLUB
does not keep free slabs on a separate list.  Besides, we currently do not
even call per-memcg shrinkers for offline memcgs.  Overall, it would
introduce much more complexity to both SLUB and memcg than this small
patch.

Regarding to SLAB, there's no problem with it, because it shrinks
per-cpu/node caches periodically.  Thanks to list_lru reparenting, we no
longer keep entries for offline cgroups in per-memcg arrays (such as
memcg_cache_params->memcg_caches), so we do not have to bother if a
per-memcg cache will be shrunk a bit later than it could be.

[1] http://thread.gmane.org/gmane.linux.kernel.mm/118649/focus=118650Signed-off-by: NVladimir Davydov <vdavydov@parallels.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>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d6e0b7fa
  11. 10 10月, 2014 1 次提交
  13. 05 6月, 2014 1 次提交
    • V
      slab: get_online_mems for kmem_cache_{create,destroy,shrink} · 03afc0e2
      由 Vladimir Davydov 提交于 
      When we create a sl[au]b cache, we allocate kmem_cache_node structures
for each online NUMA node.  To handle nodes taken online/offline, we
register memory hotplug notifier and allocate/free kmem_cache_node
corresponding to the node that changes its state for each kmem cache.

To synchronize between the two paths we hold the slab_mutex during both
the cache creationg/destruction path and while tuning per-node parts of
kmem caches in memory hotplug handler, but that's not quite right,
because it does not guarantee that a newly created cache will have all
kmem_cache_nodes initialized in case it races with memory hotplug.  For
instance, in case of slub:

    CPU0                            CPU1
    ----                            ----
    kmem_cache_create:              online_pages:
     __kmem_cache_create:            slab_memory_callback:
                                      slab_mem_going_online_callback:
                                       lock slab_mutex
                                       for each slab_caches list entry
                                           allocate kmem_cache node
                                       unlock slab_mutex
      lock slab_mutex
      init_kmem_cache_nodes:
       for_each_node_state(node, N_NORMAL_MEMORY)
           allocate kmem_cache node
      add kmem_cache to slab_caches list
      unlock slab_mutex
                                    online_pages (continued):
                                     node_states_set_node

As a result we'll get a kmem cache with not all kmem_cache_nodes
allocated.

To avoid issues like that we should hold get/put_online_mems() during
the whole kmem cache creation/destruction/shrink paths, just like we
deal with cpu hotplug.  This patch does the trick.

Note, that after it's applied, there is no need in taking the slab_mutex
for kmem_cache_shrink any more, so it is removed from there.
Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      03afc0e2
  15. 11 4月, 2014 1 次提交
  17. 05 9月, 2013 1 次提交
    • C
      mm/sl[aou]b: Move kmallocXXX functions to common code · f1b6eb6e
      由 Christoph Lameter 提交于 
      The kmalloc* functions of all slab allcoators are similar now so
lets move them into slab.h. This requires some function naming changes
in slob.

As a results of this patch there is a common set of functions for
all allocators. Also means that kmalloc_large() is now available
in general to perform large order allocations that go directly
via the page allocator. kmalloc_large() can be substituted if
kmalloc() throws warnings because of too large allocations.

kmalloc_large() has exactly the same semantics as kmalloc but
can only used for allocations > PAGE_SIZE.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>
      f1b6eb6e
  19. 08 7月, 2013 1 次提交
    • S
      slob: Check for NULL pointer before calling ctor() · c1e854e9
      由 Steven Rostedt 提交于 
      While doing some code inspection, I noticed that the slob constructor
method can be called with a NULL pointer. If memory is tight and slob
fails to allocate with slob_alloc() or slob_new_pages() it still calls
the ctor() method with a NULL pointer. Looking at the first ctor()
method I found, I noticed that it can not handle a NULL pointer (I'm
sure others probably can't either):

static void sighand_ctor(void *data)
{
        struct sighand_struct *sighand = data;

        spin_lock_init(&sighand->siglock);
        init_waitqueue_head(&sighand->signalfd_wqh);
}

The solution is to only call the ctor() method if allocation succeeded.
Acked-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>
      c1e854e9
  21. 07 7月, 2013 1 次提交
  23. 24 2月, 2013 1 次提交
  25. 19 12月, 2012 1 次提交
  27. 11 12月, 2012 1 次提交
  29. 31 10月, 2012 5 次提交
  31. 10 10月, 2012 1 次提交
    • A
      mm/slob: use min_t() to compare ARCH_SLAB_MINALIGN · baaf1dd4
      由 Arnd Bergmann 提交于 
      The definition of ARCH_SLAB_MINALIGN is architecture dependent
and can be either of type size_t or int. Comparing that value
with ARCH_KMALLOC_MINALIGN can cause harmless warnings on
platforms where they are different. Since both are always
small positive integer numbers, using the size_t type to compare
them is safe and gets rid of the warning.

Without this patch, building ARM collie_defconfig results in:

mm/slob.c: In function '__kmalloc_node':
mm/slob.c:431:152: warning: comparison of distinct pointer types lacks a cast [enabled by default]
mm/slob.c: In function 'kfree':
mm/slob.c:484:153: warning: comparison of distinct pointer types lacks a cast [enabled by default]
mm/slob.c: In function 'ksize':
mm/slob.c:503:153: warning: comparison of distinct pointer types lacks a cast [enabled by default]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NChristoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
      baaf1dd4
  33. 26 9月, 2012 1 次提交
    • D
      mm, slob: fix build breakage in __kmalloc_node_track_caller · 82bd5508
      由 David Rientjes 提交于 
      On Sat, 8 Sep 2012, Ezequiel Garcia wrote:

> @@ -454,15 +455,35 @@ void *__kmalloc_node(size_t size, gfp_t gfp, int node)
>  			gfp |= __GFP_COMP;
>  		ret = slob_new_pages(gfp, order, node);
>
> -		trace_kmalloc_node(_RET_IP_, ret,
> +		trace_kmalloc_node(caller, ret,
>  				   size, PAGE_SIZE << order, gfp, node);
>  	}
>
>  	kmemleak_alloc(ret, size, 1, gfp);
>  	return ret;
>  }
> +
> +void *__kmalloc_node(size_t size, gfp_t gfp, int node)
> +{
> +	return __do_kmalloc_node(size, gfp, node, _RET_IP_);
> +}
>  EXPORT_SYMBOL(__kmalloc_node);
>
> +#ifdef CONFIG_TRACING
> +void *__kmalloc_track_caller(size_t size, gfp_t gfp, unsigned long caller)
> +{
> +	return __do_kmalloc_node(size, gfp, NUMA_NO_NODE, caller);
> +}
> +
> +#ifdef CONFIG_NUMA
> +void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
> +					int node, unsigned long caller)
> +{
> +	return __do_kmalloc_node(size, gfp, node, caller);
> +}
> +#endif

This breaks Pekka's slab/next tree with this:

mm/slob.c: In function '__kmalloc_node_track_caller':
mm/slob.c:488: error: 'gfp' undeclared (first use in this function)
mm/slob.c:488: error: (Each undeclared identifier is reported only once
mm/slob.c:488: error: for each function it appears in.)

mm, slob: fix build breakage in __kmalloc_node_track_caller

"mm, slob: Add support for kmalloc_track_caller()" breaks the build
because gfp is undeclared.  Fix it.
Acked-by: NEzequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>
      82bd5508
  35. 25 9月, 2012 2 次提交
  37. 05 9月, 2012 8 次提交
  39. 12 7月, 2012 1 次提交
  41. 09 7月, 2012 2 次提交
  43. 14 6月, 2012 4 次提交
  45. 31 10月, 2011 1 次提交
  47. 27 7月, 2011 1 次提交