linux/mm/slab_common.c
Joonsoo Kim 95069ac8da mm/slab: fix unalignment problem on Malta with EVA due to slab merge
Unlike SLUB, sometimes, object isn't started at the beginning of the
slab in SLAB.  This causes the unalignment problem after slab merging is
supported by commit 12220dea07 ("mm/slab: support slab merge").

Following is the report from Markos that fail to boot on Malta with EVA.

    Calibrating delay loop... 19.86 BogoMIPS (lpj=99328)
    pid_max: default: 32768 minimum: 301
    Mount-cache hash table entries: 4096 (order: 0, 16384 bytes)
    Mountpoint-cache hash table entries: 4096 (order: 0, 16384 bytes)
    Kernel bug detected[#1]:
    CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.0-05639-g12220dea07f1 #1631
    task: 1f04f5d8 ti: 1f050000 task.ti: 1f050000
    epc   : 80141190 alloc_unbound_pwq+0x234/0x304
        Not tainted
    ra    : 80141184 alloc_unbound_pwq+0x228/0x304
    Process swapper/0 (pid: 1, threadinfo=1f050000, task=1f04f5d8, tls=00000000)
    Call Trace:
      alloc_unbound_pwq+0x234/0x304
      apply_workqueue_attrs+0x11c/0x294
      __alloc_workqueue_key+0x23c/0x470
      init_workqueues+0x320/0x400
      do_one_initcall+0xe8/0x23c
      kernel_init_freeable+0x9c/0x224
      kernel_init+0x10/0x100
      ret_from_kernel_thread+0x14/0x1c
    [ end trace cb88537fdc8fa200 ]
    Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

alloc_unbound_pwq() allocates slab object from pool_workqueue.  This
kmem_cache requires 256 bytes alignment, but, current merging code
doesn't honor that, and merge it with kmalloc-256.  kmalloc-256 requires
only cacheline size alignment so that above failure occurs.  However, in
x86, kmalloc-256 is luckily aligned in 256 bytes, so the problem didn't
happen on it.

To fix this problem, this patch introduces alignment mismatch check in
find_mergeable().  This will fix the problem.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reported-by: Markos Chandras <Markos.Chandras@imgtec.com>
Tested-by: Markos Chandras <Markos.Chandras@imgtec.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-13 16:17:05 -08:00

1055 lines
24 KiB
C

/*
* Slab allocator functions that are independent of the allocator strategy
*
* (C) 2012 Christoph Lameter <cl@linux.com>
*/
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/poison.h>
#include <linux/interrupt.h>
#include <linux/memory.h>
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/uaccess.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
#include <linux/memcontrol.h>
#define CREATE_TRACE_POINTS
#include <trace/events/kmem.h>
#include "slab.h"
enum slab_state slab_state;
LIST_HEAD(slab_caches);
DEFINE_MUTEX(slab_mutex);
struct kmem_cache *kmem_cache;
/*
* Set of flags that will prevent slab merging
*/
#define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
SLAB_FAILSLAB)
#define SLAB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
SLAB_CACHE_DMA | SLAB_NOTRACK)
/*
* Merge control. If this is set then no merging of slab caches will occur.
* (Could be removed. This was introduced to pacify the merge skeptics.)
*/
static int slab_nomerge;
static int __init setup_slab_nomerge(char *str)
{
slab_nomerge = 1;
return 1;
}
#ifdef CONFIG_SLUB
__setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
#endif
__setup("slab_nomerge", setup_slab_nomerge);
/*
* Determine the size of a slab object
*/
unsigned int kmem_cache_size(struct kmem_cache *s)
{
return s->object_size;
}
EXPORT_SYMBOL(kmem_cache_size);
#ifdef CONFIG_DEBUG_VM
static int kmem_cache_sanity_check(const char *name, size_t size)
{
struct kmem_cache *s = NULL;
if (!name || in_interrupt() || size < sizeof(void *) ||
size > KMALLOC_MAX_SIZE) {
pr_err("kmem_cache_create(%s) integrity check failed\n", name);
return -EINVAL;
}
list_for_each_entry(s, &slab_caches, list) {
char tmp;
int res;
/*
* This happens when the module gets unloaded and doesn't
* destroy its slab cache and no-one else reuses the vmalloc
* area of the module. Print a warning.
*/
res = probe_kernel_address(s->name, tmp);
if (res) {
pr_err("Slab cache with size %d has lost its name\n",
s->object_size);
continue;
}
}
WARN_ON(strchr(name, ' ')); /* It confuses parsers */
return 0;
}
#else
static inline int kmem_cache_sanity_check(const char *name, size_t size)
{
return 0;
}
#endif
#ifdef CONFIG_MEMCG_KMEM
static int memcg_alloc_cache_params(struct mem_cgroup *memcg,
struct kmem_cache *s, struct kmem_cache *root_cache)
{
size_t size;
if (!memcg_kmem_enabled())
return 0;
if (!memcg) {
size = offsetof(struct memcg_cache_params, memcg_caches);
size += memcg_limited_groups_array_size * sizeof(void *);
} else
size = sizeof(struct memcg_cache_params);
s->memcg_params = kzalloc(size, GFP_KERNEL);
if (!s->memcg_params)
return -ENOMEM;
if (memcg) {
s->memcg_params->memcg = memcg;
s->memcg_params->root_cache = root_cache;
} else
s->memcg_params->is_root_cache = true;
return 0;
}
static void memcg_free_cache_params(struct kmem_cache *s)
{
kfree(s->memcg_params);
}
static int memcg_update_cache_params(struct kmem_cache *s, int num_memcgs)
{
int size;
struct memcg_cache_params *new_params, *cur_params;
BUG_ON(!is_root_cache(s));
size = offsetof(struct memcg_cache_params, memcg_caches);
size += num_memcgs * sizeof(void *);
new_params = kzalloc(size, GFP_KERNEL);
if (!new_params)
return -ENOMEM;
cur_params = s->memcg_params;
memcpy(new_params->memcg_caches, cur_params->memcg_caches,
memcg_limited_groups_array_size * sizeof(void *));
new_params->is_root_cache = true;
rcu_assign_pointer(s->memcg_params, new_params);
if (cur_params)
kfree_rcu(cur_params, rcu_head);
return 0;
}
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_params(s, num_memcgs);
/*
* 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;
}
#else
static inline int memcg_alloc_cache_params(struct mem_cgroup *memcg,
struct kmem_cache *s, struct kmem_cache *root_cache)
{
return 0;
}
static inline void memcg_free_cache_params(struct kmem_cache *s)
{
}
#endif /* CONFIG_MEMCG_KMEM */
/*
* Find a mergeable slab cache
*/
int slab_unmergeable(struct kmem_cache *s)
{
if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
return 1;
if (!is_root_cache(s))
return 1;
if (s->ctor)
return 1;
/*
* We may have set a slab to be unmergeable during bootstrap.
*/
if (s->refcount < 0)
return 1;
return 0;
}
struct kmem_cache *find_mergeable(size_t size, size_t align,
unsigned long flags, const char *name, void (*ctor)(void *))
{
struct kmem_cache *s;
if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
return NULL;
if (ctor)
return NULL;
size = ALIGN(size, sizeof(void *));
align = calculate_alignment(flags, align, size);
size = ALIGN(size, align);
flags = kmem_cache_flags(size, flags, name, NULL);
list_for_each_entry(s, &slab_caches, list) {
if (slab_unmergeable(s))
continue;
if (size > s->size)
continue;
if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
continue;
/*
* Check if alignment is compatible.
* Courtesy of Adrian Drzewiecki
*/
if ((s->size & ~(align - 1)) != s->size)
continue;
if (s->size - size >= sizeof(void *))
continue;
if (IS_ENABLED(CONFIG_SLAB) && align &&
(align > s->align || s->align % align))
continue;
return s;
}
return NULL;
}
/*
* 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 *));
}
static struct kmem_cache *
do_kmem_cache_create(char *name, size_t object_size, size_t size, size_t align,
unsigned long flags, void (*ctor)(void *),
struct mem_cgroup *memcg, struct kmem_cache *root_cache)
{
struct kmem_cache *s;
int err;
err = -ENOMEM;
s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
if (!s)
goto out;
s->name = name;
s->object_size = object_size;
s->size = size;
s->align = align;
s->ctor = ctor;
err = memcg_alloc_cache_params(memcg, s, root_cache);
if (err)
goto out_free_cache;
err = __kmem_cache_create(s, flags);
if (err)
goto out_free_cache;
s->refcount = 1;
list_add(&s->list, &slab_caches);
out:
if (err)
return ERR_PTR(err);
return s;
out_free_cache:
memcg_free_cache_params(s);
kfree(s);
goto out;
}
/*
* 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.
*/
struct kmem_cache *
kmem_cache_create(const char *name, size_t size, size_t align,
unsigned long flags, void (*ctor)(void *))
{
struct kmem_cache *s;
char *cache_name;
int err;
get_online_cpus();
get_online_mems();
mutex_lock(&slab_mutex);
err = kmem_cache_sanity_check(name, size);
if (err) {
s = NULL; /* suppress uninit var warning */
goto out_unlock;
}
/*
* 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;
s = __kmem_cache_alias(name, size, align, flags, ctor);
if (s)
goto out_unlock;
cache_name = kstrdup(name, GFP_KERNEL);
if (!cache_name) {
err = -ENOMEM;
goto out_unlock;
}
s = do_kmem_cache_create(cache_name, size, size,
calculate_alignment(flags, align, size),
flags, ctor, NULL, NULL);
if (IS_ERR(s)) {
err = PTR_ERR(s);
kfree(cache_name);
}
out_unlock:
mutex_unlock(&slab_mutex);
put_online_mems();
put_online_cpus();
if (err) {
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;
}
return s;
}
EXPORT_SYMBOL(kmem_cache_create);
#ifdef CONFIG_MEMCG_KMEM
/*
* memcg_create_kmem_cache - Create a cache for a memory cgroup.
* @memcg: The memory cgroup the new cache is for.
* @root_cache: The parent of the new cache.
* @memcg_name: The name of the memory cgroup (used for naming the new cache).
*
* This function attempts to create a kmem cache that will serve allocation
* requests going from @memcg to @root_cache. The new cache inherits properties
* from its parent.
*/
struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
struct kmem_cache *root_cache,
const char *memcg_name)
{
struct kmem_cache *s = NULL;
char *cache_name;
get_online_cpus();
get_online_mems();
mutex_lock(&slab_mutex);
cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
memcg_cache_id(memcg), memcg_name);
if (!cache_name)
goto out_unlock;
s = do_kmem_cache_create(cache_name, root_cache->object_size,
root_cache->size, root_cache->align,
root_cache->flags, root_cache->ctor,
memcg, root_cache);
if (IS_ERR(s)) {
kfree(cache_name);
s = NULL;
}
out_unlock:
mutex_unlock(&slab_mutex);
put_online_mems();
put_online_cpus();
return s;
}
static int memcg_cleanup_cache_params(struct kmem_cache *s)
{
int rc;
if (!s->memcg_params ||
!s->memcg_params->is_root_cache)
return 0;
mutex_unlock(&slab_mutex);
rc = __memcg_cleanup_cache_params(s);
mutex_lock(&slab_mutex);
return rc;
}
#else
static int memcg_cleanup_cache_params(struct kmem_cache *s)
{
return 0;
}
#endif /* CONFIG_MEMCG_KMEM */
void slab_kmem_cache_release(struct kmem_cache *s)
{
kfree(s->name);
kmem_cache_free(kmem_cache, s);
}
void kmem_cache_destroy(struct kmem_cache *s)
{
get_online_cpus();
get_online_mems();
mutex_lock(&slab_mutex);
s->refcount--;
if (s->refcount)
goto out_unlock;
if (memcg_cleanup_cache_params(s) != 0)
goto out_unlock;
if (__kmem_cache_shutdown(s) != 0) {
printk(KERN_ERR "kmem_cache_destroy %s: "
"Slab cache still has objects\n", s->name);
dump_stack();
goto out_unlock;
}
list_del(&s->list);
mutex_unlock(&slab_mutex);
if (s->flags & SLAB_DESTROY_BY_RCU)
rcu_barrier();
memcg_free_cache_params(s);
#ifdef SLAB_SUPPORTS_SYSFS
sysfs_slab_remove(s);
#else
slab_kmem_cache_release(s);
#endif
goto out;
out_unlock:
mutex_unlock(&slab_mutex);
out:
put_online_mems();
put_online_cpus();
}
EXPORT_SYMBOL(kmem_cache_destroy);
/**
* kmem_cache_shrink - Shrink a cache.
* @cachep: The cache to shrink.
*
* Releases as many slabs as possible for a cache.
* To help debugging, a zero exit status indicates all slabs were released.
*/
int kmem_cache_shrink(struct kmem_cache *cachep)
{
int ret;
get_online_cpus();
get_online_mems();
ret = __kmem_cache_shrink(cachep);
put_online_mems();
put_online_cpus();
return ret;
}
EXPORT_SYMBOL(kmem_cache_shrink);
int slab_is_available(void)
{
return slab_state >= UP;
}
#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;
s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
err = __kmem_cache_create(s, flags);
if (err)
panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
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;
}
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
/*
* 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;
if (unlikely(size > KMALLOC_MAX_SIZE)) {
WARN_ON_ONCE(!(flags & __GFP_NOWARN));
return NULL;
}
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
if (unlikely((flags & GFP_DMA)))
return kmalloc_dma_caches[index];
#endif
return kmalloc_caches[index];
}
/*
* 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;
/*
* 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;
}
for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
if (!kmalloc_caches[i]) {
kmalloc_caches[i] = create_kmalloc_cache(NULL,
1 << i, flags);
}
/*
* 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);
if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
}
/* 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
}
#endif /* !CONFIG_SLOB */
/*
* To avoid unnecessary overhead, we pass through large allocation requests
* directly to the page allocator. We use __GFP_COMP, because we will need to
* know the allocation order to free the pages properly in kfree.
*/
void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
{
void *ret;
struct page *page;
flags |= __GFP_COMP;
page = alloc_kmem_pages(flags, order);
ret = page ? page_address(page) : NULL;
kmemleak_alloc(ret, size, 1, flags);
return ret;
}
EXPORT_SYMBOL(kmalloc_order);
#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
#ifdef CONFIG_SLABINFO
#ifdef CONFIG_SLAB
#define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
#else
#define SLABINFO_RIGHTS S_IRUSR
#endif
void print_slabinfo_header(struct seq_file *m)
{
/*
* 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');
}
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);
}
void *slab_next(struct seq_file *m, void *p, loff_t *pos)
{
return seq_list_next(p, &slab_caches, pos);
}
void slab_stop(struct seq_file *m, void *p)
{
mutex_unlock(&slab_mutex);
}
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) {
c = cache_from_memcg_idx(s, i);
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)
{
struct slabinfo sinfo;
memset(&sinfo, 0, sizeof(sinfo));
get_slabinfo(s, &sinfo);
memcg_accumulate_slabinfo(s, &sinfo);
seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
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;
}
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);
}
/*
* 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,
.next = slab_next,
.stop = slab_stop,
.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)
{
proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
&proc_slabinfo_operations);
return 0;
}
module_init(slab_proc_init);
#endif /* CONFIG_SLABINFO */
static __always_inline void *__do_krealloc(const void *p, size_t new_size,
gfp_t flags)
{
void *ret;
size_t ks = 0;
if (p)
ks = ksize(p);
if (ks >= new_size)
return (void *)p;
ret = kmalloc_track_caller(new_size, flags);
if (ret && p)
memcpy(ret, p, ks);
return ret;
}
/**
* __krealloc - like krealloc() but don't free @p.
* @p: object to reallocate memory for.
* @new_size: how many bytes of memory are required.
* @flags: the type of memory to allocate.
*
* This function is like krealloc() except it never frees the originally
* allocated buffer. Use this if you don't want to free the buffer immediately
* like, for example, with RCU.
*/
void *__krealloc(const void *p, size_t new_size, gfp_t flags)
{
if (unlikely(!new_size))
return ZERO_SIZE_PTR;
return __do_krealloc(p, new_size, flags);
}
EXPORT_SYMBOL(__krealloc);
/**
* krealloc - reallocate memory. The contents will remain unchanged.
* @p: object to reallocate memory for.
* @new_size: how many bytes of memory are required.
* @flags: the type of memory to allocate.
*
* The contents of the object pointed to are preserved up to the
* lesser of the new and old sizes. If @p is %NULL, krealloc()
* behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
* %NULL pointer, the object pointed to is freed.
*/
void *krealloc(const void *p, size_t new_size, gfp_t flags)
{
void *ret;
if (unlikely(!new_size)) {
kfree(p);
return ZERO_SIZE_PTR;
}
ret = __do_krealloc(p, new_size, flags);
if (ret && p != ret)
kfree(p);
return ret;
}
EXPORT_SYMBOL(krealloc);
/**
* kzfree - like kfree but zero memory
* @p: object to free memory of
*
* The memory of the object @p points to is zeroed before freed.
* If @p is %NULL, kzfree() does nothing.
*
* Note: this function zeroes the whole allocated buffer which can be a good
* deal bigger than the requested buffer size passed to kmalloc(). So be
* careful when using this function in performance sensitive code.
*/
void kzfree(const void *p)
{
size_t ks;
void *mem = (void *)p;
if (unlikely(ZERO_OR_NULL_PTR(mem)))
return;
ks = ksize(mem);
memset(mem, 0, ks);
kfree(mem);
}
EXPORT_SYMBOL(kzfree);
/* Tracepoints definitions. */
EXPORT_TRACEPOINT_SYMBOL(kmalloc);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
EXPORT_TRACEPOINT_SYMBOL(kfree);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);