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Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux

Browse Source 
Pull slab update from Pekka Enberg:
 "Highlights:

  - Fix for boot-time problems on some architectures due to
    init_lock_keys() not respecting kmalloc_caches boundaries
    (Christoph Lameter)

  - CONFIG_SLUB_CPU_PARTIAL requested by RT folks (Joonsoo Kim)

  - Fix for excessive slab freelist draining (Wanpeng Li)

  - SLUB and SLOB cleanups and fixes (various people)"

I ended up editing the branch, and this avoids two commits at the end
that were immediately reverted, and I instead just applied the oneliner
fix in between myself.

* 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
  slub: Check for page NULL before doing the node_match check
  mm/slab: Give s_next and s_stop slab-specific names
  slob: Check for NULL pointer before calling ctor()
  slub: Make cpu partial slab support configurable
  slab: add kmalloc() to kernel API documentation
  slab: fix init_lock_keys
  slob: use DIV_ROUND_UP where possible
  slub: do not put a slab to cpu partial list when cpu_partial is 0
  mm/slub: Use node_nr_slabs and node_nr_objs in get_slabinfo
  mm/slub: Drop unnecessary nr_partials
  mm/slab: Fix /proc/slabinfo unwriteable for slab
  mm/slab: Sharing s_next and s_stop between slab and slub
  mm/slab: Fix drain freelist excessively
  slob: Rework #ifdeffery in slab.h
  mm, slab: moved kmem_cache_alloc_node comment to correct place
This commit is contained in:
Linus Torvalds 2013-07-14 15:14:29 -07:00
commit 54be820019
8 changed files with 121 additions and 69 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
include/linux/slab.h
View File

@ -169,11 +169,7 @@ struct kmem_cache {
struct list_head list; /* List of all slab caches on the system */
};
#define KMALLOC_MAX_SIZE (1UL << 30)
#include <linux/slob_def.h>
#else /* CONFIG_SLOB */
#endif /* CONFIG_SLOB */
/*
* Kmalloc array related definitions
@ -195,7 +191,9 @@ struct kmem_cache {
#ifndef KMALLOC_SHIFT_LOW
#define KMALLOC_SHIFT_LOW 5
#endif
#else
#endif
#ifdef CONFIG_SLUB
/*
* SLUB allocates up to order 2 pages directly and otherwise
* passes the request to the page allocator.
@ -207,6 +205,19 @@ struct kmem_cache {
#endif
#endif
#ifdef CONFIG_SLOB
/*
* SLOB passes all page size and larger requests to the page allocator.
* No kmalloc array is necessary since objects of different sizes can
* be allocated from the same page.
*/
#define KMALLOC_SHIFT_MAX 30
#define KMALLOC_SHIFT_HIGH PAGE_SHIFT
#ifndef KMALLOC_SHIFT_LOW
#define KMALLOC_SHIFT_LOW 3
#endif
#endif
/* Maximum allocatable size */
#define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
/* Maximum size for which we actually use a slab cache */
@ -221,6 +232,7 @@ struct kmem_cache {
#define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
#endif
#ifndef CONFIG_SLOB
extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
#ifdef CONFIG_ZONE_DMA
extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
@ -275,13 +287,18 @@ static __always_inline int kmalloc_index(size_t size)
/* Will never be reached. Needed because the compiler may complain */
return -1;
}
#endif /* !CONFIG_SLOB */
#ifdef CONFIG_SLAB
#include <linux/slab_def.h>
#elif defined(CONFIG_SLUB)
#endif
#ifdef CONFIG_SLUB
#include <linux/slub_def.h>
#else
#error "Unknown slab allocator"
#endif
#ifdef CONFIG_SLOB
#include <linux/slob_def.h>
#endif
/*
@ -291,6 +308,7 @@ static __always_inline int kmalloc_index(size_t size)
*/
static __always_inline int kmalloc_size(int n)
{
#ifndef CONFIG_SLOB
if (n > 2)
return 1 << n;
@ -299,10 +317,9 @@ static __always_inline int kmalloc_size(int n)
if (n == 2 && KMALLOC_MIN_SIZE <= 64)
return 192;
#endif
return 0;
}
#endif /* !CONFIG_SLOB */
/*
* Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
@ -356,9 +373,8 @@ int cache_show(struct kmem_cache *s, struct seq_file *m);
void print_slabinfo_header(struct seq_file *m);
/**
* kmalloc_array - allocate memory for an array.
* @n: number of elements.
* @size: element size.
* kmalloc - allocate memory
* @size: how many bytes of memory are required.
* @flags: the type of memory to allocate.
*
* The @flags argument may be one of:
@ -405,6 +421,17 @@ void print_slabinfo_header(struct seq_file *m);
* There are other flags available as well, but these are not intended
* for general use, and so are not documented here. For a full list of
* potential flags, always refer to linux/gfp.h.
*
* kmalloc is the normal method of allocating memory
* in the kernel.
*/
static __always_inline void *kmalloc(size_t size, gfp_t flags);
/**
* kmalloc_array - allocate memory for an array.
* @n: number of elements.
* @size: element size.
* @flags: the type of memory to allocate (see kmalloc).
*/
static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
{
@ -428,7 +455,7 @@ static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
/**
* kmalloc_node - allocate memory from a specific node
* @size: how many bytes of memory are required.
* @flags: the type of memory to allocate (see kcalloc).
* @flags: the type of memory to allocate (see kmalloc).
* @node: node to allocate from.
*
* kmalloc() for non-local nodes, used to allocate from a specific node

8
include/linux/slob_def.h
View File

@ -18,14 +18,6 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
return __kmalloc_node(size, flags, node);
}
/**
* kmalloc - allocate memory
* @size: how many bytes of memory are required.
* @flags: the type of memory to allocate (see kcalloc).
*
* kmalloc is the normal method of allocating memory
* in the kernel.
*/
static __always_inline void *kmalloc(size_t size, gfp_t flags)
{
return __kmalloc_node(size, flags, NUMA_NO_NODE);

11
init/Kconfig
View File

@ -1596,6 +1596,17 @@ config SLOB
endchoice
config SLUB_CPU_PARTIAL
default y
depends on SLUB
bool "SLUB per cpu partial cache"
help
Per cpu partial caches accellerate objects allocation and freeing
that is local to a processor at the price of more indeterminism
in the latency of the free. On overflow these caches will be cleared
which requires the taking of locks that may cause latency spikes.
Typically one would choose no for a realtime system.
config MMAP_ALLOW_UNINITIALIZED
bool "Allow mmapped anonymous memory to be uninitialized"
depends on EXPERT && !MMU

51
mm/slab.c
View File

@ -565,7 +565,7 @@ static void init_node_lock_keys(int q)
if (slab_state < UP)
return;
for (i = 1; i < PAGE_SHIFT + MAX_ORDER; i++) {
for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) {
struct kmem_cache_node *n;
struct kmem_cache *cache = kmalloc_caches[i];
@ -1180,6 +1180,12 @@ static int init_cache_node_node(int node)
return 0;
}
static inline int slabs_tofree(struct kmem_cache *cachep,
struct kmem_cache_node *n)
{
return (n->free_objects + cachep->num - 1) / cachep->num;
}
static void __cpuinit cpuup_canceled(long cpu)
{
struct kmem_cache *cachep;
@ -1241,7 +1247,7 @@ free_array_cache:
n = cachep->node[node];
if (!n)
continue;
drain_freelist(cachep, n, n->free_objects);
drain_freelist(cachep, n, slabs_tofree(cachep, n));
}
}
@ -1408,7 +1414,7 @@ static int __meminit drain_cache_node_node(int node)
if (!n)
continue;
drain_freelist(cachep, n, n->free_objects);
drain_freelist(cachep, n, slabs_tofree(cachep, n));
if (!list_empty(&n->slabs_full) ||
!list_empty(&n->slabs_partial)) {
@ -2532,7 +2538,7 @@ static int __cache_shrink(struct kmem_cache *cachep)
if (!n)
continue;
drain_freelist(cachep, n, n->free_objects);
drain_freelist(cachep, n, slabs_tofree(cachep, n));
ret += !list_empty(&n->slabs_full) ||
!list_empty(&n->slabs_partial);
@ -3338,18 +3344,6 @@ done:
return obj;
}
/**
* kmem_cache_alloc_node - Allocate an object on the specified node
* @cachep: The cache to allocate from.
* @flags: See kmalloc().
* @nodeid: node number of the target node.
* @caller: return address of caller, used for debug information
*
* Identical to kmem_cache_alloc but it will allocate memory on the given
* node, which can improve the performance for cpu bound structures.
*
* Fallback to other node is possible if __GFP_THISNODE is not set.
*/
static __always_inline void *
slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
unsigned long caller)
@ -3643,6 +3637,17 @@ EXPORT_SYMBOL(kmem_cache_alloc_trace);
#endif
#ifdef CONFIG_NUMA
/**
* kmem_cache_alloc_node - Allocate an object on the specified node
* @cachep: The cache to allocate from.
* @flags: See kmalloc().
* @nodeid: node number of the target node.
*
* Identical to kmem_cache_alloc but it will allocate memory on the given
* node, which can improve the performance for cpu bound structures.
*
* Fallback to other node is possible if __GFP_THISNODE is not set.
*/
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
{
void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
@ -4431,20 +4436,10 @@ static int leaks_show(struct seq_file *m, void *p)
return 0;
}
static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
return seq_list_next(p, &slab_caches, pos);
}
static void s_stop(struct seq_file *m, void *p)
{
mutex_unlock(&slab_mutex);
}
static const struct seq_operations slabstats_op = {
.start = leaks_start,
.next = s_next,
.stop = s_stop,
.next = slab_next,
.stop = slab_stop,
.show = leaks_show,
};

3
mm/slab.h
View File

@ -271,3 +271,6 @@ struct kmem_cache_node {
#endif
};
void *slab_next(struct seq_file *m, void *p, loff_t *pos);
void slab_stop(struct seq_file *m, void *p);

18
mm/slab_common.c
View File

@ -497,6 +497,13 @@ void __init create_kmalloc_caches(unsigned long flags)
#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)
{
/*
@ -531,12 +538,12 @@ static void *s_start(struct seq_file *m, loff_t *pos)
return seq_list_start(&slab_caches, *pos);
}
static void *s_next(struct seq_file *m, void *p, loff_t *pos)
void *slab_next(struct seq_file *m, void *p, loff_t *pos)
{
return seq_list_next(p, &slab_caches, pos);
}
static void s_stop(struct seq_file *m, void *p)
void slab_stop(struct seq_file *m, void *p)
{
mutex_unlock(&slab_mutex);
}
@ -613,8 +620,8 @@ static int s_show(struct seq_file *m, void *p)
*/
static const struct seq_operations slabinfo_op = {
.start = s_start,
.next = s_next,
.stop = s_stop,
.next = slab_next,
.stop = slab_stop,
.show = s_show,
};
@ -633,7 +640,8 @@ static const struct file_operations proc_slabinfo_operations = {
static int __init slab_proc_init(void)
{
proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations);
proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
&proc_slabinfo_operations);
return 0;
}
module_init(slab_proc_init);

4
mm/slob.c
View File

@ -122,7 +122,7 @@ static inline void clear_slob_page_free(struct page *sp)
}
#define SLOB_UNIT sizeof(slob_t)
#define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT)
#define SLOB_UNITS(size) DIV_ROUND_UP(size, SLOB_UNIT)
/*
* struct slob_rcu is inserted at the tail of allocated slob blocks, which
@ -554,7 +554,7 @@ void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
flags, node);
}
if (c->ctor)
if (b && c->ctor)
c->ctor(b);
kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags);

38
mm/slub.c
View File

@ -123,6 +123,15 @@ static inline int kmem_cache_debug(struct kmem_cache *s)
#endif
}
static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
{
#ifdef CONFIG_SLUB_CPU_PARTIAL
return !kmem_cache_debug(s);
#else
return false;
#endif
}
/*
* Issues still to be resolved:
*
@ -1573,7 +1582,8 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
put_cpu_partial(s, page, 0);
stat(s, CPU_PARTIAL_NODE);
}
if (kmem_cache_debug(s) || available > s->cpu_partial / 2)
if (!kmem_cache_has_cpu_partial(s)
|| available > s->cpu_partial / 2)
break;
}
@ -1884,6 +1894,7 @@ redo:
static void unfreeze_partials(struct kmem_cache *s,
struct kmem_cache_cpu *c)
{
#ifdef CONFIG_SLUB_CPU_PARTIAL
struct kmem_cache_node *n = NULL, *n2 = NULL;
struct page *page, *discard_page = NULL;
@ -1938,6 +1949,7 @@ static void unfreeze_partials(struct kmem_cache *s,
discard_slab(s, page);
stat(s, FREE_SLAB);
}
#endif
}
/*
@ -1951,10 +1963,14 @@ static void unfreeze_partials(struct kmem_cache *s,
*/
static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
{
#ifdef CONFIG_SLUB_CPU_PARTIAL
struct page *oldpage;
int pages;
int pobjects;
if (!s->cpu_partial)
return;
do {
pages = 0;
pobjects = 0;
@ -1987,6 +2003,7 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
page->next = oldpage;
} while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
#endif
}
static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
@ -2358,7 +2375,7 @@ redo:
object = c->freelist;
page = c->page;
if (unlikely(!object || !node_match(page, node)))
if (unlikely(!object || !page || !node_match(page, node)))
object = __slab_alloc(s, gfpflags, node, addr, c);
else {
@ -2495,7 +2512,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
new.inuse--;
if ((!new.inuse || !prior) && !was_frozen) {
if (!kmem_cache_debug(s) && !prior)
if (kmem_cache_has_cpu_partial(s) && !prior)
/*
* Slab was on no list before and will be partially empty
@ -2550,8 +2567,9 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
* Objects left in the slab. If it was not on the partial list before
* then add it.
*/
if (kmem_cache_debug(s) && unlikely(!prior)) {
remove_full(s, page);
if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) {
if (kmem_cache_debug(s))
remove_full(s, page);
add_partial(n, page, DEACTIVATE_TO_TAIL);
stat(s, FREE_ADD_PARTIAL);
}
@ -3059,7 +3077,7 @@ static int kmem_cache_open(struct kmem_cache *s, unsigned long flags)
* per node list when we run out of per cpu objects. We only fetch 50%
* to keep some capacity around for frees.
*/
if (kmem_cache_debug(s))
if (!kmem_cache_has_cpu_partial(s))
s->cpu_partial = 0;
else if (s->size >= PAGE_SIZE)
s->cpu_partial = 2;
@ -4456,7 +4474,7 @@ static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
err = strict_strtoul(buf, 10, &objects);
if (err)
return err;
if (objects && kmem_cache_debug(s))
if (objects && !kmem_cache_has_cpu_partial(s))
return -EINVAL;
s->cpu_partial = objects;
@ -5269,7 +5287,6 @@ __initcall(slab_sysfs_init);
#ifdef CONFIG_SLABINFO
void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
{
unsigned long nr_partials = 0;
unsigned long nr_slabs = 0;
unsigned long nr_objs = 0;
unsigned long nr_free = 0;
@ -5281,9 +5298,8 @@ void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
if (!n)
continue;
nr_partials += n->nr_partial;
nr_slabs += atomic_long_read(&n->nr_slabs);
nr_objs += atomic_long_read(&n->total_objects);
nr_slabs += node_nr_slabs(n);
nr_objs += node_nr_objs(n);
nr_free += count_partial(n, count_free);
}