2012-07-06 22:25:10 +02:00
|
|
|
/*
|
|
|
|
* Slab allocator functions that are independent of the allocator strategy
|
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|
|
*
|
|
|
|
* (C) 2012 Christoph Lameter <cl@linux.com>
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|
|
|
*/
|
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|
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#include <linux/slab.h>
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|
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#include <linux/mm.h>
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#include <linux/poison.h>
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#include <linux/interrupt.h>
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#include <linux/memory.h>
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#include <linux/compiler.h>
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#include <linux/module.h>
|
2012-07-06 22:25:13 +02:00
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|
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#include <linux/cpu.h>
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#include <linux/uaccess.h>
|
2012-10-19 16:20:25 +02:00
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|
#include <linux/seq_file.h>
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#include <linux/proc_fs.h>
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2012-07-06 22:25:10 +02:00
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|
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/page.h>
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2012-12-18 23:22:34 +01:00
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|
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#include <linux/memcontrol.h>
|
2013-09-04 18:35:34 +02:00
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#include <trace/events/kmem.h>
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2012-07-06 22:25:10 +02:00
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2012-07-06 22:25:11 +02:00
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|
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#include "slab.h"
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enum slab_state slab_state;
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2012-07-06 22:25:12 +02:00
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|
LIST_HEAD(slab_caches);
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|
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DEFINE_MUTEX(slab_mutex);
|
2012-09-05 02:20:33 +02:00
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|
|
struct kmem_cache *kmem_cache;
|
2012-07-06 22:25:11 +02:00
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|
|
2012-08-16 09:09:46 +02:00
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|
|
#ifdef CONFIG_DEBUG_VM
|
2012-12-18 23:22:34 +01:00
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|
static int kmem_cache_sanity_check(struct mem_cgroup *memcg, const char *name,
|
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|
|
size_t size)
|
2012-07-06 22:25:10 +02:00
|
|
|
{
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|
|
|
struct kmem_cache *s = NULL;
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|
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|
|
if (!name || in_interrupt() || size < sizeof(void *) ||
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|
|
size > KMALLOC_MAX_SIZE) {
|
2012-08-16 09:09:46 +02:00
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|
|
pr_err("kmem_cache_create(%s) integrity check failed\n", name);
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|
|
return -EINVAL;
|
2012-07-06 22:25:10 +02:00
|
|
|
}
|
2012-08-16 09:12:18 +02:00
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|
|
2012-07-06 22:25:13 +02:00
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list_for_each_entry(s, &slab_caches, list) {
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|
char tmp;
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|
|
|
int res;
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|
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|
|
|
|
|
/*
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|
|
|
* This happens when the module gets unloaded and doesn't
|
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|
|
* destroy its slab cache and no-one else reuses the vmalloc
|
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|
|
* area of the module. Print a warning.
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|
|
|
*/
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|
res = probe_kernel_address(s->name, tmp);
|
|
|
|
if (res) {
|
2012-08-16 09:09:46 +02:00
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|
|
pr_err("Slab cache with size %d has lost its name\n",
|
2012-07-06 22:25:13 +02:00
|
|
|
s->object_size);
|
|
|
|
continue;
|
|
|
|
}
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|
|
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|
2014-03-04 23:13:47 +01:00
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|
|
#if !defined(CONFIG_SLUB)
|
2012-12-18 23:22:34 +01:00
|
|
|
/*
|
|
|
|
* For simplicity, we won't check this in the list of memcg
|
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|
|
* caches. We have control over memcg naming, and if there
|
|
|
|
* aren't duplicates in the global list, there won't be any
|
|
|
|
* duplicates in the memcg lists as well.
|
|
|
|
*/
|
|
|
|
if (!memcg && !strcmp(s->name, name)) {
|
2012-08-16 09:09:46 +02:00
|
|
|
pr_err("%s (%s): Cache name already exists.\n",
|
|
|
|
__func__, name);
|
2012-07-06 22:25:13 +02:00
|
|
|
dump_stack();
|
|
|
|
s = NULL;
|
2012-08-16 09:09:46 +02:00
|
|
|
return -EINVAL;
|
2012-07-06 22:25:13 +02:00
|
|
|
}
|
2013-09-21 23:56:34 +02:00
|
|
|
#endif
|
2012-07-06 22:25:13 +02:00
|
|
|
}
|
|
|
|
|
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|
|
WARN_ON(strchr(name, ' ')); /* It confuses parsers */
|
2012-08-16 09:09:46 +02:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
#else
|
2012-12-18 23:22:34 +01:00
|
|
|
static inline int kmem_cache_sanity_check(struct mem_cgroup *memcg,
|
|
|
|
const char *name, size_t size)
|
2012-08-16 09:09:46 +02:00
|
|
|
{
|
|
|
|
return 0;
|
|
|
|
}
|
2012-07-06 22:25:13 +02:00
|
|
|
#endif
|
|
|
|
|
memcg: allocate memory for memcg caches whenever a new memcg appears
Every cache that is considered a root cache (basically the "original"
caches, tied to the root memcg/no-memcg) will have an array that should be
large enough to store a cache pointer per each memcg in the system.
Theoreticaly, this is as high as 1 << sizeof(css_id), which is currently
in the 64k pointers range. Most of the time, we won't be using that much.
What goes in this patch, is a simple scheme to dynamically allocate such
an array, in order to minimize memory usage for memcg caches. Because we
would also like to avoid allocations all the time, at least for now, the
array will only grow. It will tend to be big enough to hold the maximum
number of kmem-limited memcgs ever achieved.
We'll allocate it to be a minimum of 64 kmem-limited memcgs. When we have
more than that, we'll start doubling the size of this array every time the
limit is reached.
Because we are only considering kmem limited memcgs, a natural point for
this to happen is when we write to the limit. At that point, we already
have set_limit_mutex held, so that will become our natural synchronization
mechanism.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 23:22:38 +01:00
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
|
|
int memcg_update_all_caches(int num_memcgs)
|
|
|
|
{
|
|
|
|
struct kmem_cache *s;
|
|
|
|
int ret = 0;
|
|
|
|
mutex_lock(&slab_mutex);
|
|
|
|
|
|
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
|
|
if (!is_root_cache(s))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
ret = memcg_update_cache_size(s, num_memcgs);
|
|
|
|
/*
|
|
|
|
* See comment in memcontrol.c, memcg_update_cache_size:
|
|
|
|
* Instead of freeing the memory, we'll just leave the caches
|
|
|
|
* up to this point in an updated state.
|
|
|
|
*/
|
|
|
|
if (ret)
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
memcg_update_array_size(num_memcgs);
|
|
|
|
out:
|
|
|
|
mutex_unlock(&slab_mutex);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
2012-11-28 17:23:16 +01:00
|
|
|
/*
|
|
|
|
* Figure out what the alignment of the objects will be given a set of
|
|
|
|
* flags, a user specified alignment and the size of the objects.
|
|
|
|
*/
|
|
|
|
unsigned long calculate_alignment(unsigned long flags,
|
|
|
|
unsigned long align, unsigned long size)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* If the user wants hardware cache aligned objects then follow that
|
|
|
|
* suggestion if the object is sufficiently large.
|
|
|
|
*
|
|
|
|
* The hardware cache alignment cannot override the specified
|
|
|
|
* alignment though. If that is greater then use it.
|
|
|
|
*/
|
|
|
|
if (flags & SLAB_HWCACHE_ALIGN) {
|
|
|
|
unsigned long ralign = cache_line_size();
|
|
|
|
while (size <= ralign / 2)
|
|
|
|
ralign /= 2;
|
|
|
|
align = max(align, ralign);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (align < ARCH_SLAB_MINALIGN)
|
|
|
|
align = ARCH_SLAB_MINALIGN;
|
|
|
|
|
|
|
|
return ALIGN(align, sizeof(void *));
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2012-08-16 09:09:46 +02:00
|
|
|
/*
|
|
|
|
* kmem_cache_create - Create a cache.
|
|
|
|
* @name: A string which is used in /proc/slabinfo to identify this cache.
|
|
|
|
* @size: The size of objects to be created in this cache.
|
|
|
|
* @align: The required alignment for the objects.
|
|
|
|
* @flags: SLAB flags
|
|
|
|
* @ctor: A constructor for the objects.
|
|
|
|
*
|
|
|
|
* Returns a ptr to the cache on success, NULL on failure.
|
|
|
|
* Cannot be called within a interrupt, but can be interrupted.
|
|
|
|
* The @ctor is run when new pages are allocated by the cache.
|
|
|
|
*
|
|
|
|
* The flags are
|
|
|
|
*
|
|
|
|
* %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
|
|
|
|
* to catch references to uninitialised memory.
|
|
|
|
*
|
|
|
|
* %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
|
|
|
|
* for buffer overruns.
|
|
|
|
*
|
|
|
|
* %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
|
|
|
|
* cacheline. This can be beneficial if you're counting cycles as closely
|
|
|
|
* as davem.
|
|
|
|
*/
|
|
|
|
|
2012-12-18 23:22:34 +01:00
|
|
|
struct kmem_cache *
|
|
|
|
kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size,
|
2012-12-18 23:23:03 +01:00
|
|
|
size_t align, unsigned long flags, void (*ctor)(void *),
|
|
|
|
struct kmem_cache *parent_cache)
|
2012-08-16 09:09:46 +02:00
|
|
|
{
|
|
|
|
struct kmem_cache *s = NULL;
|
2014-01-24 00:52:55 +01:00
|
|
|
int err;
|
2012-07-06 22:25:10 +02:00
|
|
|
|
2012-08-16 09:09:46 +02:00
|
|
|
get_online_cpus();
|
|
|
|
mutex_lock(&slab_mutex);
|
2012-09-05 02:20:33 +02:00
|
|
|
|
2014-01-24 00:52:55 +01:00
|
|
|
err = kmem_cache_sanity_check(memcg, name, size);
|
|
|
|
if (err)
|
|
|
|
goto out_unlock;
|
2012-09-05 02:20:33 +02:00
|
|
|
|
memcg, slab: fix races in per-memcg cache creation/destruction
We obtain a per-memcg cache from a root kmem_cache by dereferencing an
entry of the root cache's memcg_params::memcg_caches array. If we find
no cache for a memcg there on allocation, we initiate the memcg cache
creation (see memcg_kmem_get_cache()). The cache creation proceeds
asynchronously in memcg_create_kmem_cache() in order to avoid lock
clashes, so there can be several threads trying to create the same
kmem_cache concurrently, but only one of them may succeed. However, due
to a race in the code, it is not always true. The point is that the
memcg_caches array can be relocated when we activate kmem accounting for
a memcg (see memcg_update_all_caches(), memcg_update_cache_size()). If
memcg_update_cache_size() and memcg_create_kmem_cache() proceed
concurrently as described below, we can leak a kmem_cache.
Asume two threads schedule creation of the same kmem_cache. One of them
successfully creates it. Another one should fail then, but if
memcg_create_kmem_cache() interleaves with memcg_update_cache_size() as
follows, it won't:
memcg_create_kmem_cache() memcg_update_cache_size()
(called w/o mutexes held) (called with slab_mutex,
set_limit_mutex held)
------------------------- -------------------------
mutex_lock(&memcg_cache_mutex)
s->memcg_params=kzalloc(...)
new_cachep=cache_from_memcg_idx(cachep,idx)
// new_cachep==NULL => proceed to creation
s->memcg_params->memcg_caches[i]
=cur_params->memcg_caches[i]
// kmem_cache_create_memcg takes slab_mutex
// so we will hang around until
// memcg_update_cache_size finishes, but
// nothing will prevent it from succeeding so
// memcg_caches[idx] will be overwritten in
// memcg_register_cache!
new_cachep = kmem_cache_create_memcg(...)
mutex_unlock(&memcg_cache_mutex)
Let's fix this by moving the check for existence of the memcg cache to
kmem_cache_create_memcg() to be called under the slab_mutex and make it
return NULL if so.
A similar race is possible when destroying a memcg cache (see
kmem_cache_destroy()). Since memcg_unregister_cache(), which clears the
pointer in the memcg_caches array, is called w/o protection, we can race
with memcg_update_cache_size() and omit clearing the pointer. Therefore
memcg_unregister_cache() should be moved before we release the
slab_mutex.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: 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>
2014-01-24 00:53:02 +01:00
|
|
|
if (memcg) {
|
|
|
|
/*
|
|
|
|
* Since per-memcg caches are created asynchronously on first
|
|
|
|
* allocation (see memcg_kmem_get_cache()), several threads can
|
|
|
|
* try to create the same cache, but only one of them may
|
|
|
|
* succeed. Therefore if we get here and see the cache has
|
|
|
|
* already been created, we silently return NULL.
|
|
|
|
*/
|
|
|
|
if (cache_from_memcg_idx(parent_cache, memcg_cache_id(memcg)))
|
|
|
|
goto out_unlock;
|
|
|
|
}
|
|
|
|
|
2012-10-17 13:36:51 +02:00
|
|
|
/*
|
|
|
|
* Some allocators will constraint the set of valid flags to a subset
|
|
|
|
* of all flags. We expect them to define CACHE_CREATE_MASK in this
|
|
|
|
* case, and we'll just provide them with a sanitized version of the
|
|
|
|
* passed flags.
|
|
|
|
*/
|
|
|
|
flags &= CACHE_CREATE_MASK;
|
2012-09-05 02:20:33 +02:00
|
|
|
|
2012-12-18 23:22:34 +01:00
|
|
|
s = __kmem_cache_alias(memcg, name, size, align, flags, ctor);
|
2012-09-05 02:18:32 +02:00
|
|
|
if (s)
|
2014-01-24 00:52:55 +01:00
|
|
|
goto out_unlock;
|
2012-09-05 02:18:32 +02:00
|
|
|
|
2014-01-24 00:52:55 +01:00
|
|
|
err = -ENOMEM;
|
2012-09-05 02:20:34 +02:00
|
|
|
s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
|
2014-01-24 00:52:55 +01:00
|
|
|
if (!s)
|
|
|
|
goto out_unlock;
|
2012-12-18 23:22:34 +01:00
|
|
|
|
2014-01-24 00:52:55 +01:00
|
|
|
s->object_size = s->size = size;
|
|
|
|
s->align = calculate_alignment(flags, align, size);
|
|
|
|
s->ctor = ctor;
|
2012-09-05 01:18:33 +02:00
|
|
|
|
2014-01-24 00:52:55 +01:00
|
|
|
s->name = kstrdup(name, GFP_KERNEL);
|
|
|
|
if (!s->name)
|
|
|
|
goto out_free_cache;
|
|
|
|
|
2014-01-24 00:52:56 +01:00
|
|
|
err = memcg_alloc_cache_params(memcg, s, parent_cache);
|
2014-01-24 00:52:55 +01:00
|
|
|
if (err)
|
|
|
|
goto out_free_cache;
|
|
|
|
|
|
|
|
err = __kmem_cache_create(s, flags);
|
|
|
|
if (err)
|
|
|
|
goto out_free_cache;
|
2012-09-05 01:38:33 +02:00
|
|
|
|
2014-01-24 00:52:55 +01:00
|
|
|
s->refcount = 1;
|
|
|
|
list_add(&s->list, &slab_caches);
|
memcg, slab: clean up memcg cache initialization/destruction
Currently, we have rather a messy function set relating to per-memcg
kmem cache initialization/destruction.
Per-memcg caches are created in memcg_create_kmem_cache(). This
function calls kmem_cache_create_memcg() to allocate and initialize a
kmem cache and then "registers" the new cache in the
memcg_params::memcg_caches array of the parent cache.
During its work-flow, kmem_cache_create_memcg() executes the following
memcg-related functions:
- memcg_alloc_cache_params(), to initialize memcg_params of the newly
created cache;
- memcg_cache_list_add(), to add the new cache to the memcg_slab_caches
list.
On the other hand, kmem_cache_destroy() called on a cache destruction
only calls memcg_release_cache(), which does all the work: it cleans the
reference to the cache in its parent's memcg_params::memcg_caches,
removes the cache from the memcg_slab_caches list, and frees
memcg_params.
Such an inconsistency between destruction and initialization paths make
the code difficult to read, so let's clean this up a bit.
This patch moves all the code relating to registration of per-memcg
caches (adding to memcg list, setting the pointer to a cache from its
parent) to the newly created memcg_register_cache() and
memcg_unregister_cache() functions making the initialization and
destruction paths look symmetrical.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: 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>
2014-01-24 00:52:58 +01:00
|
|
|
memcg_register_cache(s);
|
2014-01-24 00:52:55 +01:00
|
|
|
|
|
|
|
out_unlock:
|
2012-07-06 22:25:13 +02:00
|
|
|
mutex_unlock(&slab_mutex);
|
|
|
|
put_online_cpus();
|
|
|
|
|
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 23:05:48 +01:00
|
|
|
if (err) {
|
|
|
|
/*
|
|
|
|
* There is no point in flooding logs with warnings or
|
|
|
|
* especially crashing the system if we fail to create a cache
|
|
|
|
* for a memcg. In this case we will be accounting the memcg
|
|
|
|
* allocation to the root cgroup until we succeed to create its
|
|
|
|
* own cache, but it isn't that critical.
|
|
|
|
*/
|
|
|
|
if (!memcg)
|
|
|
|
return NULL;
|
|
|
|
|
2012-09-05 02:20:33 +02:00
|
|
|
if (flags & SLAB_PANIC)
|
|
|
|
panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
|
|
|
|
name, err);
|
|
|
|
else {
|
|
|
|
printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
|
|
|
|
name, err);
|
|
|
|
dump_stack();
|
|
|
|
}
|
|
|
|
return NULL;
|
|
|
|
}
|
2012-07-06 22:25:10 +02:00
|
|
|
return s;
|
2014-01-24 00:52:55 +01:00
|
|
|
|
|
|
|
out_free_cache:
|
2014-01-24 00:52:56 +01:00
|
|
|
memcg_free_cache_params(s);
|
2014-01-24 00:52:55 +01:00
|
|
|
kfree(s->name);
|
|
|
|
kmem_cache_free(kmem_cache, s);
|
|
|
|
goto out_unlock;
|
2012-07-06 22:25:10 +02:00
|
|
|
}
|
2012-12-18 23:22:34 +01:00
|
|
|
|
|
|
|
struct kmem_cache *
|
|
|
|
kmem_cache_create(const char *name, size_t size, size_t align,
|
|
|
|
unsigned long flags, void (*ctor)(void *))
|
|
|
|
{
|
2012-12-18 23:23:03 +01:00
|
|
|
return kmem_cache_create_memcg(NULL, name, size, align, flags, ctor, NULL);
|
2012-12-18 23:22:34 +01:00
|
|
|
}
|
2012-07-06 22:25:10 +02:00
|
|
|
EXPORT_SYMBOL(kmem_cache_create);
|
2012-07-06 22:25:11 +02:00
|
|
|
|
2012-09-05 01:18:33 +02:00
|
|
|
void kmem_cache_destroy(struct kmem_cache *s)
|
|
|
|
{
|
2012-12-18 23:22:55 +01:00
|
|
|
/* Destroy all the children caches if we aren't a memcg cache */
|
|
|
|
kmem_cache_destroy_memcg_children(s);
|
|
|
|
|
2012-09-05 01:18:33 +02:00
|
|
|
get_online_cpus();
|
|
|
|
mutex_lock(&slab_mutex);
|
|
|
|
s->refcount--;
|
|
|
|
if (!s->refcount) {
|
|
|
|
list_del(&s->list);
|
|
|
|
|
|
|
|
if (!__kmem_cache_shutdown(s)) {
|
memcg, slab: fix races in per-memcg cache creation/destruction
We obtain a per-memcg cache from a root kmem_cache by dereferencing an
entry of the root cache's memcg_params::memcg_caches array. If we find
no cache for a memcg there on allocation, we initiate the memcg cache
creation (see memcg_kmem_get_cache()). The cache creation proceeds
asynchronously in memcg_create_kmem_cache() in order to avoid lock
clashes, so there can be several threads trying to create the same
kmem_cache concurrently, but only one of them may succeed. However, due
to a race in the code, it is not always true. The point is that the
memcg_caches array can be relocated when we activate kmem accounting for
a memcg (see memcg_update_all_caches(), memcg_update_cache_size()). If
memcg_update_cache_size() and memcg_create_kmem_cache() proceed
concurrently as described below, we can leak a kmem_cache.
Asume two threads schedule creation of the same kmem_cache. One of them
successfully creates it. Another one should fail then, but if
memcg_create_kmem_cache() interleaves with memcg_update_cache_size() as
follows, it won't:
memcg_create_kmem_cache() memcg_update_cache_size()
(called w/o mutexes held) (called with slab_mutex,
set_limit_mutex held)
------------------------- -------------------------
mutex_lock(&memcg_cache_mutex)
s->memcg_params=kzalloc(...)
new_cachep=cache_from_memcg_idx(cachep,idx)
// new_cachep==NULL => proceed to creation
s->memcg_params->memcg_caches[i]
=cur_params->memcg_caches[i]
// kmem_cache_create_memcg takes slab_mutex
// so we will hang around until
// memcg_update_cache_size finishes, but
// nothing will prevent it from succeeding so
// memcg_caches[idx] will be overwritten in
// memcg_register_cache!
new_cachep = kmem_cache_create_memcg(...)
mutex_unlock(&memcg_cache_mutex)
Let's fix this by moving the check for existence of the memcg cache to
kmem_cache_create_memcg() to be called under the slab_mutex and make it
return NULL if so.
A similar race is possible when destroying a memcg cache (see
kmem_cache_destroy()). Since memcg_unregister_cache(), which clears the
pointer in the memcg_caches array, is called w/o protection, we can race
with memcg_update_cache_size() and omit clearing the pointer. Therefore
memcg_unregister_cache() should be moved before we release the
slab_mutex.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: 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>
2014-01-24 00:53:02 +01:00
|
|
|
memcg_unregister_cache(s);
|
2012-10-08 09:26:01 +02:00
|
|
|
mutex_unlock(&slab_mutex);
|
2012-09-05 01:18:33 +02:00
|
|
|
if (s->flags & SLAB_DESTROY_BY_RCU)
|
|
|
|
rcu_barrier();
|
|
|
|
|
memcg, slab: clean up memcg cache initialization/destruction
Currently, we have rather a messy function set relating to per-memcg
kmem cache initialization/destruction.
Per-memcg caches are created in memcg_create_kmem_cache(). This
function calls kmem_cache_create_memcg() to allocate and initialize a
kmem cache and then "registers" the new cache in the
memcg_params::memcg_caches array of the parent cache.
During its work-flow, kmem_cache_create_memcg() executes the following
memcg-related functions:
- memcg_alloc_cache_params(), to initialize memcg_params of the newly
created cache;
- memcg_cache_list_add(), to add the new cache to the memcg_slab_caches
list.
On the other hand, kmem_cache_destroy() called on a cache destruction
only calls memcg_release_cache(), which does all the work: it cleans the
reference to the cache in its parent's memcg_params::memcg_caches,
removes the cache from the memcg_slab_caches list, and frees
memcg_params.
Such an inconsistency between destruction and initialization paths make
the code difficult to read, so let's clean this up a bit.
This patch moves all the code relating to registration of per-memcg
caches (adding to memcg list, setting the pointer to a cache from its
parent) to the newly created memcg_register_cache() and
memcg_unregister_cache() functions making the initialization and
destruction paths look symmetrical.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: 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>
2014-01-24 00:52:58 +01:00
|
|
|
memcg_free_cache_params(s);
|
2012-09-05 01:18:33 +02:00
|
|
|
kfree(s->name);
|
2012-09-05 02:18:32 +02:00
|
|
|
kmem_cache_free(kmem_cache, s);
|
2012-09-05 01:18:33 +02:00
|
|
|
} else {
|
|
|
|
list_add(&s->list, &slab_caches);
|
2012-10-08 09:26:01 +02:00
|
|
|
mutex_unlock(&slab_mutex);
|
2012-09-05 01:18:33 +02:00
|
|
|
printk(KERN_ERR "kmem_cache_destroy %s: Slab cache still has objects\n",
|
|
|
|
s->name);
|
|
|
|
dump_stack();
|
|
|
|
}
|
2012-10-08 09:26:01 +02:00
|
|
|
} else {
|
|
|
|
mutex_unlock(&slab_mutex);
|
2012-09-05 01:18:33 +02:00
|
|
|
}
|
|
|
|
put_online_cpus();
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(kmem_cache_destroy);
|
|
|
|
|
2012-07-06 22:25:11 +02:00
|
|
|
int slab_is_available(void)
|
|
|
|
{
|
|
|
|
return slab_state >= UP;
|
|
|
|
}
|
2012-10-19 16:20:25 +02:00
|
|
|
|
2012-11-28 17:23:07 +01:00
|
|
|
#ifndef CONFIG_SLOB
|
|
|
|
/* Create a cache during boot when no slab services are available yet */
|
|
|
|
void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
|
|
|
|
unsigned long flags)
|
|
|
|
{
|
|
|
|
int err;
|
|
|
|
|
|
|
|
s->name = name;
|
|
|
|
s->size = s->object_size = size;
|
2012-11-28 17:23:16 +01:00
|
|
|
s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
|
2012-11-28 17:23:07 +01:00
|
|
|
err = __kmem_cache_create(s, flags);
|
|
|
|
|
|
|
|
if (err)
|
2013-01-10 20:00:53 +01:00
|
|
|
panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
|
2012-11-28 17:23:07 +01:00
|
|
|
name, size, err);
|
|
|
|
|
|
|
|
s->refcount = -1; /* Exempt from merging for now */
|
|
|
|
}
|
|
|
|
|
|
|
|
struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
|
|
|
|
unsigned long flags)
|
|
|
|
{
|
|
|
|
struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
|
|
|
|
|
|
|
|
if (!s)
|
|
|
|
panic("Out of memory when creating slab %s\n", name);
|
|
|
|
|
|
|
|
create_boot_cache(s, name, size, flags);
|
|
|
|
list_add(&s->list, &slab_caches);
|
|
|
|
s->refcount = 1;
|
|
|
|
return s;
|
|
|
|
}
|
|
|
|
|
2013-01-10 20:12:17 +01:00
|
|
|
struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
|
|
|
|
EXPORT_SYMBOL(kmalloc_caches);
|
|
|
|
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
|
|
struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
|
|
|
|
EXPORT_SYMBOL(kmalloc_dma_caches);
|
|
|
|
#endif
|
|
|
|
|
2013-01-10 20:14:19 +01:00
|
|
|
/*
|
|
|
|
* Conversion table for small slabs sizes / 8 to the index in the
|
|
|
|
* kmalloc array. This is necessary for slabs < 192 since we have non power
|
|
|
|
* of two cache sizes there. The size of larger slabs can be determined using
|
|
|
|
* fls.
|
|
|
|
*/
|
|
|
|
static s8 size_index[24] = {
|
|
|
|
3, /* 8 */
|
|
|
|
4, /* 16 */
|
|
|
|
5, /* 24 */
|
|
|
|
5, /* 32 */
|
|
|
|
6, /* 40 */
|
|
|
|
6, /* 48 */
|
|
|
|
6, /* 56 */
|
|
|
|
6, /* 64 */
|
|
|
|
1, /* 72 */
|
|
|
|
1, /* 80 */
|
|
|
|
1, /* 88 */
|
|
|
|
1, /* 96 */
|
|
|
|
7, /* 104 */
|
|
|
|
7, /* 112 */
|
|
|
|
7, /* 120 */
|
|
|
|
7, /* 128 */
|
|
|
|
2, /* 136 */
|
|
|
|
2, /* 144 */
|
|
|
|
2, /* 152 */
|
|
|
|
2, /* 160 */
|
|
|
|
2, /* 168 */
|
|
|
|
2, /* 176 */
|
|
|
|
2, /* 184 */
|
|
|
|
2 /* 192 */
|
|
|
|
};
|
|
|
|
|
|
|
|
static inline int size_index_elem(size_t bytes)
|
|
|
|
{
|
|
|
|
return (bytes - 1) / 8;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Find the kmem_cache structure that serves a given size of
|
|
|
|
* allocation
|
|
|
|
*/
|
|
|
|
struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
|
|
|
|
{
|
|
|
|
int index;
|
|
|
|
|
2013-08-02 04:02:42 +02:00
|
|
|
if (unlikely(size > KMALLOC_MAX_SIZE)) {
|
2013-06-10 21:18:00 +02:00
|
|
|
WARN_ON_ONCE(!(flags & __GFP_NOWARN));
|
2013-05-03 17:43:18 +02:00
|
|
|
return NULL;
|
2013-06-10 21:18:00 +02:00
|
|
|
}
|
2013-05-03 17:43:18 +02:00
|
|
|
|
2013-01-10 20:14:19 +01:00
|
|
|
if (size <= 192) {
|
|
|
|
if (!size)
|
|
|
|
return ZERO_SIZE_PTR;
|
|
|
|
|
|
|
|
index = size_index[size_index_elem(size)];
|
|
|
|
} else
|
|
|
|
index = fls(size - 1);
|
|
|
|
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
2013-02-04 15:46:46 +01:00
|
|
|
if (unlikely((flags & GFP_DMA)))
|
2013-01-10 20:14:19 +01:00
|
|
|
return kmalloc_dma_caches[index];
|
|
|
|
|
|
|
|
#endif
|
|
|
|
return kmalloc_caches[index];
|
|
|
|
}
|
|
|
|
|
2013-01-10 20:12:17 +01:00
|
|
|
/*
|
|
|
|
* Create the kmalloc array. Some of the regular kmalloc arrays
|
|
|
|
* may already have been created because they were needed to
|
|
|
|
* enable allocations for slab creation.
|
|
|
|
*/
|
|
|
|
void __init create_kmalloc_caches(unsigned long flags)
|
|
|
|
{
|
|
|
|
int i;
|
|
|
|
|
2013-01-10 20:14:19 +01:00
|
|
|
/*
|
|
|
|
* Patch up the size_index table if we have strange large alignment
|
|
|
|
* requirements for the kmalloc array. This is only the case for
|
|
|
|
* MIPS it seems. The standard arches will not generate any code here.
|
|
|
|
*
|
|
|
|
* Largest permitted alignment is 256 bytes due to the way we
|
|
|
|
* handle the index determination for the smaller caches.
|
|
|
|
*
|
|
|
|
* Make sure that nothing crazy happens if someone starts tinkering
|
|
|
|
* around with ARCH_KMALLOC_MINALIGN
|
|
|
|
*/
|
|
|
|
BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
|
|
|
|
(KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
|
|
|
|
|
|
|
|
for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
|
|
|
|
int elem = size_index_elem(i);
|
|
|
|
|
|
|
|
if (elem >= ARRAY_SIZE(size_index))
|
|
|
|
break;
|
|
|
|
size_index[elem] = KMALLOC_SHIFT_LOW;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (KMALLOC_MIN_SIZE >= 64) {
|
|
|
|
/*
|
|
|
|
* The 96 byte size cache is not used if the alignment
|
|
|
|
* is 64 byte.
|
|
|
|
*/
|
|
|
|
for (i = 64 + 8; i <= 96; i += 8)
|
|
|
|
size_index[size_index_elem(i)] = 7;
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
if (KMALLOC_MIN_SIZE >= 128) {
|
|
|
|
/*
|
|
|
|
* The 192 byte sized cache is not used if the alignment
|
|
|
|
* is 128 byte. Redirect kmalloc to use the 256 byte cache
|
|
|
|
* instead.
|
|
|
|
*/
|
|
|
|
for (i = 128 + 8; i <= 192; i += 8)
|
|
|
|
size_index[size_index_elem(i)] = 8;
|
|
|
|
}
|
2013-05-03 20:04:18 +02:00
|
|
|
for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
|
|
|
|
if (!kmalloc_caches[i]) {
|
2013-01-10 20:12:17 +01:00
|
|
|
kmalloc_caches[i] = create_kmalloc_cache(NULL,
|
|
|
|
1 << i, flags);
|
2013-05-08 21:56:28 +02:00
|
|
|
}
|
2013-01-10 20:12:17 +01:00
|
|
|
|
2013-05-08 21:56:28 +02:00
|
|
|
/*
|
|
|
|
* Caches that are not of the two-to-the-power-of size.
|
|
|
|
* These have to be created immediately after the
|
|
|
|
* earlier power of two caches
|
|
|
|
*/
|
|
|
|
if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
|
|
|
|
kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags);
|
2013-05-03 20:04:18 +02:00
|
|
|
|
2013-05-08 21:56:28 +02:00
|
|
|
if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
|
|
|
|
kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
|
2013-05-03 20:04:18 +02:00
|
|
|
}
|
|
|
|
|
2013-01-10 20:12:17 +01:00
|
|
|
/* Kmalloc array is now usable */
|
|
|
|
slab_state = UP;
|
|
|
|
|
|
|
|
for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
|
|
|
|
struct kmem_cache *s = kmalloc_caches[i];
|
|
|
|
char *n;
|
|
|
|
|
|
|
|
if (s) {
|
|
|
|
n = kasprintf(GFP_NOWAIT, "kmalloc-%d", kmalloc_size(i));
|
|
|
|
|
|
|
|
BUG_ON(!n);
|
|
|
|
s->name = n;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
|
|
for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
|
|
|
|
struct kmem_cache *s = kmalloc_caches[i];
|
|
|
|
|
|
|
|
if (s) {
|
|
|
|
int size = kmalloc_size(i);
|
|
|
|
char *n = kasprintf(GFP_NOWAIT,
|
|
|
|
"dma-kmalloc-%d", size);
|
|
|
|
|
|
|
|
BUG_ON(!n);
|
|
|
|
kmalloc_dma_caches[i] = create_kmalloc_cache(n,
|
|
|
|
size, SLAB_CACHE_DMA | flags);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
}
|
2012-11-28 17:23:07 +01:00
|
|
|
#endif /* !CONFIG_SLOB */
|
|
|
|
|
2013-09-04 18:35:34 +02:00
|
|
|
#ifdef CONFIG_TRACING
|
|
|
|
void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
|
|
|
|
{
|
|
|
|
void *ret = kmalloc_order(size, flags, order);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(kmalloc_order_trace);
|
|
|
|
#endif
|
2012-11-28 17:23:07 +01:00
|
|
|
|
2012-10-19 16:20:25 +02:00
|
|
|
#ifdef CONFIG_SLABINFO
|
2013-07-04 02:33:24 +02:00
|
|
|
|
|
|
|
#ifdef CONFIG_SLAB
|
|
|
|
#define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
|
|
|
|
#else
|
|
|
|
#define SLABINFO_RIGHTS S_IRUSR
|
|
|
|
#endif
|
|
|
|
|
2012-12-18 23:23:01 +01:00
|
|
|
void print_slabinfo_header(struct seq_file *m)
|
2012-10-19 16:20:26 +02:00
|
|
|
{
|
|
|
|
/*
|
|
|
|
* Output format version, so at least we can change it
|
|
|
|
* without _too_ many complaints.
|
|
|
|
*/
|
|
|
|
#ifdef CONFIG_DEBUG_SLAB
|
|
|
|
seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
|
|
|
|
#else
|
|
|
|
seq_puts(m, "slabinfo - version: 2.1\n");
|
|
|
|
#endif
|
|
|
|
seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
|
|
|
|
"<objperslab> <pagesperslab>");
|
|
|
|
seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
|
|
|
|
seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
|
|
|
|
#ifdef CONFIG_DEBUG_SLAB
|
|
|
|
seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
|
|
|
|
"<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
|
|
|
|
seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
|
|
|
|
#endif
|
|
|
|
seq_putc(m, '\n');
|
|
|
|
}
|
|
|
|
|
2012-10-19 16:20:25 +02:00
|
|
|
static void *s_start(struct seq_file *m, loff_t *pos)
|
|
|
|
{
|
|
|
|
loff_t n = *pos;
|
|
|
|
|
|
|
|
mutex_lock(&slab_mutex);
|
|
|
|
if (!n)
|
|
|
|
print_slabinfo_header(m);
|
|
|
|
|
|
|
|
return seq_list_start(&slab_caches, *pos);
|
|
|
|
}
|
|
|
|
|
2013-07-08 02:08:28 +02:00
|
|
|
void *slab_next(struct seq_file *m, void *p, loff_t *pos)
|
2012-10-19 16:20:25 +02:00
|
|
|
{
|
|
|
|
return seq_list_next(p, &slab_caches, pos);
|
|
|
|
}
|
|
|
|
|
2013-07-08 02:08:28 +02:00
|
|
|
void slab_stop(struct seq_file *m, void *p)
|
2012-10-19 16:20:25 +02:00
|
|
|
{
|
|
|
|
mutex_unlock(&slab_mutex);
|
|
|
|
}
|
|
|
|
|
2012-12-18 23:23:01 +01:00
|
|
|
static void
|
|
|
|
memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
|
|
|
|
{
|
|
|
|
struct kmem_cache *c;
|
|
|
|
struct slabinfo sinfo;
|
|
|
|
int i;
|
|
|
|
|
|
|
|
if (!is_root_cache(s))
|
|
|
|
return;
|
|
|
|
|
|
|
|
for_each_memcg_cache_index(i) {
|
2013-11-13 00:08:23 +01:00
|
|
|
c = cache_from_memcg_idx(s, i);
|
2012-12-18 23:23:01 +01:00
|
|
|
if (!c)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
memset(&sinfo, 0, sizeof(sinfo));
|
|
|
|
get_slabinfo(c, &sinfo);
|
|
|
|
|
|
|
|
info->active_slabs += sinfo.active_slabs;
|
|
|
|
info->num_slabs += sinfo.num_slabs;
|
|
|
|
info->shared_avail += sinfo.shared_avail;
|
|
|
|
info->active_objs += sinfo.active_objs;
|
|
|
|
info->num_objs += sinfo.num_objs;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
int cache_show(struct kmem_cache *s, struct seq_file *m)
|
2012-10-19 16:20:25 +02:00
|
|
|
{
|
2012-10-19 16:20:27 +02:00
|
|
|
struct slabinfo sinfo;
|
|
|
|
|
|
|
|
memset(&sinfo, 0, sizeof(sinfo));
|
|
|
|
get_slabinfo(s, &sinfo);
|
|
|
|
|
2012-12-18 23:23:01 +01:00
|
|
|
memcg_accumulate_slabinfo(s, &sinfo);
|
|
|
|
|
2012-10-19 16:20:27 +02:00
|
|
|
seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
|
2012-12-18 23:23:01 +01:00
|
|
|
cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
|
2012-10-19 16:20:27 +02:00
|
|
|
sinfo.objects_per_slab, (1 << sinfo.cache_order));
|
|
|
|
|
|
|
|
seq_printf(m, " : tunables %4u %4u %4u",
|
|
|
|
sinfo.limit, sinfo.batchcount, sinfo.shared);
|
|
|
|
seq_printf(m, " : slabdata %6lu %6lu %6lu",
|
|
|
|
sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
|
|
|
|
slabinfo_show_stats(m, s);
|
|
|
|
seq_putc(m, '\n');
|
|
|
|
return 0;
|
2012-10-19 16:20:25 +02:00
|
|
|
}
|
|
|
|
|
2012-12-18 23:23:01 +01:00
|
|
|
static int s_show(struct seq_file *m, void *p)
|
|
|
|
{
|
|
|
|
struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
|
|
|
|
|
|
|
|
if (!is_root_cache(s))
|
|
|
|
return 0;
|
|
|
|
return cache_show(s, m);
|
|
|
|
}
|
|
|
|
|
2012-10-19 16:20:25 +02:00
|
|
|
/*
|
|
|
|
* slabinfo_op - iterator that generates /proc/slabinfo
|
|
|
|
*
|
|
|
|
* Output layout:
|
|
|
|
* cache-name
|
|
|
|
* num-active-objs
|
|
|
|
* total-objs
|
|
|
|
* object size
|
|
|
|
* num-active-slabs
|
|
|
|
* total-slabs
|
|
|
|
* num-pages-per-slab
|
|
|
|
* + further values on SMP and with statistics enabled
|
|
|
|
*/
|
|
|
|
static const struct seq_operations slabinfo_op = {
|
|
|
|
.start = s_start,
|
2013-07-08 02:08:28 +02:00
|
|
|
.next = slab_next,
|
|
|
|
.stop = slab_stop,
|
2012-10-19 16:20:25 +02:00
|
|
|
.show = s_show,
|
|
|
|
};
|
|
|
|
|
|
|
|
static int slabinfo_open(struct inode *inode, struct file *file)
|
|
|
|
{
|
|
|
|
return seq_open(file, &slabinfo_op);
|
|
|
|
}
|
|
|
|
|
|
|
|
static const struct file_operations proc_slabinfo_operations = {
|
|
|
|
.open = slabinfo_open,
|
|
|
|
.read = seq_read,
|
|
|
|
.write = slabinfo_write,
|
|
|
|
.llseek = seq_lseek,
|
|
|
|
.release = seq_release,
|
|
|
|
};
|
|
|
|
|
|
|
|
static int __init slab_proc_init(void)
|
|
|
|
{
|
2013-07-04 02:33:24 +02:00
|
|
|
proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
|
|
|
|
&proc_slabinfo_operations);
|
2012-10-19 16:20:25 +02:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
module_init(slab_proc_init);
|
|
|
|
#endif /* CONFIG_SLABINFO */
|