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Merge branches 'slab/next' and 'slub/partial' into slab/for-linus

This commit is contained in:
Pekka Enberg 2011-10-26 18:09:12 +03:00
parent 3cfef95246 fe35317865 dcc3be6a54
commit e182a345d4
6 changed files with 425 additions and 182 deletions
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2
Documentation/vm/00-INDEX
View File

@ -30,8 +30,6 @@ page_migration
- description of page migration in NUMA systems.
pagemap.txt
- pagemap, from the userspace perspective
slabinfo.c
- source code for a tool to get reports about slabs.
slub.txt
- a short users guide for SLUB.
unevictable-lru.txt

14
include/linux/mm_types.h
View File

@ -79,9 +79,21 @@ struct page {
};
/* Third double word block */
struct list_head lru; /* Pageout list, eg. active_list
union {
struct list_head lru; /* Pageout list, eg. active_list
* protected by zone->lru_lock !
*/
struct { /* slub per cpu partial pages */
struct page *next; /* Next partial slab */
#ifdef CONFIG_64BIT
int pages; /* Nr of partial slabs left */
int pobjects; /* Approximate # of objects */
#else
short int pages;
short int pobjects;
#endif
};
};
/* Remainder is not double word aligned */
union {

4
include/linux/slub_def.h
View File

@ -36,12 +36,15 @@ enum stat_item {
ORDER_FALLBACK, /* Number of times fallback was necessary */
CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */
CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
CPU_PARTIAL_FREE, /* USed cpu partial on free */
NR_SLUB_STAT_ITEMS };
struct kmem_cache_cpu {
void **freelist; /* Pointer to next available object */
unsigned long tid; /* Globally unique transaction id */
struct page *page; /* The slab from which we are allocating */
struct page *partial; /* Partially allocated frozen slabs */
int node; /* The node of the page (or -1 for debug) */
#ifdef CONFIG_SLUB_STATS
unsigned stat[NR_SLUB_STAT_ITEMS];
@ -79,6 +82,7 @@ struct kmem_cache {
int size; /* The size of an object including meta data */
int objsize; /* The size of an object without meta data */
int offset; /* Free pointer offset. */
int cpu_partial; /* Number of per cpu partial objects to keep around */
struct kmem_cache_order_objects oo;
/* Allocation and freeing of slabs */

19
mm/slab.c
View File

@ -1851,15 +1851,15 @@ static void dump_line(char *data, int offset, int limit)
unsigned char error = 0;
int bad_count = 0;
printk(KERN_ERR "%03x:", offset);
printk(KERN_ERR "%03x: ", offset);
for (i = 0; i < limit; i++) {
if (data[offset + i] != POISON_FREE) {
error = data[offset + i];
bad_count++;
}
printk(" %02x", (unsigned char)data[offset + i]);
}
printk("\n");
print_hex_dump(KERN_CONT, "", 0, 16, 1,
&data[offset], limit, 1);
if (bad_count == 1) {
error ^= POISON_FREE;
@ -3039,14 +3039,9 @@ bad:
printk(KERN_ERR "slab: Internal list corruption detected in "
"cache '%s'(%d), slabp %p(%d). Hexdump:\n",
cachep->name, cachep->num, slabp, slabp->inuse);
for (i = 0;
i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
i++) {
if (i % 16 == 0)
printk("\n%03x:", i);
printk(" %02x", ((unsigned char *)slabp)[i]);
}
printk("\n");
print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp,
sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t),
1);
BUG();
}
}
@ -4584,7 +4579,7 @@ static const struct file_operations proc_slabstats_operations = {
static int __init slab_proc_init(void)
{
proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
proc_create("slabinfo",S_IWUSR|S_IRUSR,NULL,&proc_slabinfo_operations);
#ifdef CONFIG_DEBUG_SLAB_LEAK
proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations);
#endif

558
mm/slub.c
View File

@ -467,34 +467,8 @@ static int disable_higher_order_debug;
*/
static void print_section(char *text, u8 *addr, unsigned int length)
{
int i, offset;
int newline = 1;
char ascii[17];
ascii[16] = 0;
for (i = 0; i < length; i++) {
if (newline) {
printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
newline = 0;
}
printk(KERN_CONT " %02x", addr[i]);
offset = i % 16;
ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
if (offset == 15) {
printk(KERN_CONT " %s\n", ascii);
newline = 1;
}
}
if (!newline) {
i %= 16;
while (i < 16) {
printk(KERN_CONT " ");
ascii[i] = ' ';
i++;
}
printk(KERN_CONT " %s\n", ascii);
}
print_hex_dump(KERN_ERR, text, DUMP_PREFIX_ADDRESS, 16, 1, addr,
length, 1);
}
static struct track *get_track(struct kmem_cache *s, void *object,
@ -625,12 +599,12 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
p, p - addr, get_freepointer(s, p));
if (p > addr + 16)
print_section("Bytes b4", p - 16, 16);
print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE));
print_section("Bytes b4 ", p - 16, 16);
print_section("Object ", p, min_t(unsigned long, s->objsize,
PAGE_SIZE));
if (s->flags & SLAB_RED_ZONE)
print_section("Redzone", p + s->objsize,
print_section("Redzone ", p + s->objsize,
s->inuse - s->objsize);
if (s->offset)
@ -643,7 +617,7 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
if (off != s->size)
/* Beginning of the filler is the free pointer */
print_section("Padding", p + off, s->size - off);
print_section("Padding ", p + off, s->size - off);
dump_stack();
}
@ -838,7 +812,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page)
end--;
slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
print_section("Padding", end - remainder, remainder);
print_section("Padding ", end - remainder, remainder);
restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
return 0;
@ -987,7 +961,7 @@ static void trace(struct kmem_cache *s, struct page *page, void *object,
page->freelist);
if (!alloc)
print_section("Object", (void *)object, s->objsize);
print_section("Object ", (void *)object, s->objsize);
dump_stack();
}
@ -1447,7 +1421,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
set_freepointer(s, last, NULL);
page->freelist = start;
page->inuse = 0;
page->inuse = page->objects;
page->frozen = 1;
out:
return page;
@ -1534,7 +1508,7 @@ static inline void add_partial(struct kmem_cache_node *n,
struct page *page, int tail)
{
n->nr_partial++;
if (tail)
if (tail == DEACTIVATE_TO_TAIL)
list_add_tail(&page->lru, &n->partial);
else
list_add(&page->lru, &n->partial);
@ -1554,10 +1528,13 @@ static inline void remove_partial(struct kmem_cache_node *n,
* Lock slab, remove from the partial list and put the object into the
* per cpu freelist.
*
* Returns a list of objects or NULL if it fails.
*
* Must hold list_lock.
*/
static inline int acquire_slab(struct kmem_cache *s,
struct kmem_cache_node *n, struct page *page)
static inline void *acquire_slab(struct kmem_cache *s,
struct kmem_cache_node *n, struct page *page,
int mode)
{
void *freelist;
unsigned long counters;
@ -1572,7 +1549,8 @@ static inline int acquire_slab(struct kmem_cache *s,
freelist = page->freelist;
counters = page->counters;
new.counters = counters;
new.inuse = page->objects;
if (mode)
new.inuse = page->objects;
VM_BUG_ON(new.frozen);
new.frozen = 1;
@ -1583,32 +1561,19 @@ static inline int acquire_slab(struct kmem_cache *s,
"lock and freeze"));
remove_partial(n, page);
if (freelist) {
/* Populate the per cpu freelist */
this_cpu_write(s->cpu_slab->freelist, freelist);
this_cpu_write(s->cpu_slab->page, page);
this_cpu_write(s->cpu_slab->node, page_to_nid(page));
return 1;
} else {
/*
* Slab page came from the wrong list. No object to allocate
* from. Put it onto the correct list and continue partial
* scan.
*/
printk(KERN_ERR "SLUB: %s : Page without available objects on"
" partial list\n", s->name);
return 0;
}
return freelist;
}
static int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain);
/*
* Try to allocate a partial slab from a specific node.
*/
static struct page *get_partial_node(struct kmem_cache *s,
struct kmem_cache_node *n)
static void *get_partial_node(struct kmem_cache *s,
struct kmem_cache_node *n, struct kmem_cache_cpu *c)
{
struct page *page;
struct page *page, *page2;
void *object = NULL;
/*
* Racy check. If we mistakenly see no partial slabs then we
@ -1620,26 +1585,43 @@ static struct page *get_partial_node(struct kmem_cache *s,
return NULL;
spin_lock(&n->list_lock);
list_for_each_entry(page, &n->partial, lru)
if (acquire_slab(s, n, page))
goto out;
page = NULL;
out:
list_for_each_entry_safe(page, page2, &n->partial, lru) {
void *t = acquire_slab(s, n, page, object == NULL);
int available;
if (!t)
break;
if (!object) {
c->page = page;
c->node = page_to_nid(page);
stat(s, ALLOC_FROM_PARTIAL);
object = t;
available = page->objects - page->inuse;
} else {
page->freelist = t;
available = put_cpu_partial(s, page, 0);
}
if (kmem_cache_debug(s) || available > s->cpu_partial / 2)
break;
}
spin_unlock(&n->list_lock);
return page;
return object;
}
/*
* Get a page from somewhere. Search in increasing NUMA distances.
*/
static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags,
struct kmem_cache_cpu *c)
{
#ifdef CONFIG_NUMA
struct zonelist *zonelist;
struct zoneref *z;
struct zone *zone;
enum zone_type high_zoneidx = gfp_zone(flags);
struct page *page;
void *object;
/*
* The defrag ratio allows a configuration of the tradeoffs between
@ -1672,10 +1654,10 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
n->nr_partial > s->min_partial) {
page = get_partial_node(s, n);
if (page) {
object = get_partial_node(s, n, c);
if (object) {
put_mems_allowed();
return page;
return object;
}
}
}
@ -1687,16 +1669,17 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
/*
* Get a partial page, lock it and return it.
*/
static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
struct kmem_cache_cpu *c)
{
struct page *page;
void *object;
int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
page = get_partial_node(s, get_node(s, searchnode));
if (page || node != NUMA_NO_NODE)
return page;
object = get_partial_node(s, get_node(s, searchnode), c);
if (object || node != NUMA_NO_NODE)
return object;
return get_any_partial(s, flags);
return get_any_partial(s, flags, c);
}
#ifdef CONFIG_PREEMPT
@ -1765,9 +1748,6 @@ void init_kmem_cache_cpus(struct kmem_cache *s)
for_each_possible_cpu(cpu)
per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
}
/*
* Remove the cpu slab
*/
/*
* Remove the cpu slab
@ -1781,13 +1761,13 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
enum slab_modes l = M_NONE, m = M_NONE;
void *freelist;
void *nextfree;
int tail = 0;
int tail = DEACTIVATE_TO_HEAD;
struct page new;
struct page old;
if (page->freelist) {
stat(s, DEACTIVATE_REMOTE_FREES);
tail = 1;
tail = DEACTIVATE_TO_TAIL;
}
c->tid = next_tid(c->tid);
@ -1893,7 +1873,7 @@ redo:
if (m == M_PARTIAL) {
add_partial(n, page, tail);
stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
stat(s, tail);
} else if (m == M_FULL) {
@ -1920,6 +1900,123 @@ redo:
}
}
/* Unfreeze all the cpu partial slabs */
static void unfreeze_partials(struct kmem_cache *s)
{
struct kmem_cache_node *n = NULL;
struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab);
struct page *page;
while ((page = c->partial)) {
enum slab_modes { M_PARTIAL, M_FREE };
enum slab_modes l, m;
struct page new;
struct page old;
c->partial = page->next;
l = M_FREE;
do {
old.freelist = page->freelist;
old.counters = page->counters;
VM_BUG_ON(!old.frozen);
new.counters = old.counters;
new.freelist = old.freelist;
new.frozen = 0;
if (!new.inuse && (!n || n->nr_partial > s->min_partial))
m = M_FREE;
else {
struct kmem_cache_node *n2 = get_node(s,
page_to_nid(page));
m = M_PARTIAL;
if (n != n2) {
if (n)
spin_unlock(&n->list_lock);
n = n2;
spin_lock(&n->list_lock);
}
}
if (l != m) {
if (l == M_PARTIAL)
remove_partial(n, page);
else
add_partial(n, page, 1);
l = m;
}
} while (!cmpxchg_double_slab(s, page,
old.freelist, old.counters,
new.freelist, new.counters,
"unfreezing slab"));
if (m == M_FREE) {
stat(s, DEACTIVATE_EMPTY);
discard_slab(s, page);
stat(s, FREE_SLAB);
}
}
if (n)
spin_unlock(&n->list_lock);
}
/*
* Put a page that was just frozen (in __slab_free) into a partial page
* slot if available. This is done without interrupts disabled and without
* preemption disabled. The cmpxchg is racy and may put the partial page
* onto a random cpus partial slot.
*
* If we did not find a slot then simply move all the partials to the
* per node partial list.
*/
int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
{
struct page *oldpage;
int pages;
int pobjects;
do {
pages = 0;
pobjects = 0;
oldpage = this_cpu_read(s->cpu_slab->partial);
if (oldpage) {
pobjects = oldpage->pobjects;
pages = oldpage->pages;
if (drain && pobjects > s->cpu_partial) {
unsigned long flags;
/*
* partial array is full. Move the existing
* set to the per node partial list.
*/
local_irq_save(flags);
unfreeze_partials(s);
local_irq_restore(flags);
pobjects = 0;
pages = 0;
}
}
pages++;
pobjects += page->objects - page->inuse;
page->pages = pages;
page->pobjects = pobjects;
page->next = oldpage;
} while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
stat(s, CPU_PARTIAL_FREE);
return pobjects;
}
static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
{
stat(s, CPUSLAB_FLUSH);
@ -1935,8 +2032,12 @@ static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
{
struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
if (likely(c && c->page))
flush_slab(s, c);
if (likely(c)) {
if (c->page)
flush_slab(s, c);
unfreeze_partials(s);
}
}
static void flush_cpu_slab(void *d)
@ -2027,12 +2128,39 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
}
}
static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
int node, struct kmem_cache_cpu **pc)
{
void *object;
struct kmem_cache_cpu *c;
struct page *page = new_slab(s, flags, node);
if (page) {
c = __this_cpu_ptr(s->cpu_slab);
if (c->page)
flush_slab(s, c);
/*
* No other reference to the page yet so we can
* muck around with it freely without cmpxchg
*/
object = page->freelist;
page->freelist = NULL;
stat(s, ALLOC_SLAB);
c->node = page_to_nid(page);
c->page = page;
*pc = c;
} else
object = NULL;
return object;
}
/*
* Slow path. The lockless freelist is empty or we need to perform
* debugging duties.
*
* Interrupts are disabled.
*
* Processing is still very fast if new objects have been freed to the
* regular freelist. In that case we simply take over the regular freelist
* as the lockless freelist and zap the regular freelist.
@ -2049,7 +2177,6 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
unsigned long addr, struct kmem_cache_cpu *c)
{
void **object;
struct page *page;
unsigned long flags;
struct page new;
unsigned long counters;
@ -2064,13 +2191,9 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
c = this_cpu_ptr(s->cpu_slab);
#endif
/* We handle __GFP_ZERO in the caller */
gfpflags &= ~__GFP_ZERO;
page = c->page;
if (!page)
if (!c->page)
goto new_slab;
redo:
if (unlikely(!node_match(c, node))) {
stat(s, ALLOC_NODE_MISMATCH);
deactivate_slab(s, c);
@ -2080,8 +2203,8 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
stat(s, ALLOC_SLOWPATH);
do {
object = page->freelist;
counters = page->counters;
object = c->page->freelist;
counters = c->page->counters;
new.counters = counters;
VM_BUG_ON(!new.frozen);
@ -2093,17 +2216,17 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
*
* If there are objects left then we retrieve them
* and use them to refill the per cpu queue.
*/
*/
new.inuse = page->objects;
new.inuse = c->page->objects;
new.frozen = object != NULL;
} while (!__cmpxchg_double_slab(s, page,
} while (!__cmpxchg_double_slab(s, c->page,
object, counters,
NULL, new.counters,
"__slab_alloc"));
if (unlikely(!object)) {
if (!object) {
c->page = NULL;
stat(s, DEACTIVATE_BYPASS);
goto new_slab;
@ -2112,58 +2235,47 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
stat(s, ALLOC_REFILL);
load_freelist:
VM_BUG_ON(!page->frozen);
c->freelist = get_freepointer(s, object);
c->tid = next_tid(c->tid);
local_irq_restore(flags);
return object;
new_slab:
page = get_partial(s, gfpflags, node);
if (page) {
stat(s, ALLOC_FROM_PARTIAL);
object = c->freelist;
if (kmem_cache_debug(s))
goto debug;
goto load_freelist;
if (c->partial) {
c->page = c->partial;
c->partial = c->page->next;
c->node = page_to_nid(c->page);
stat(s, CPU_PARTIAL_ALLOC);
c->freelist = NULL;
goto redo;
}
page = new_slab(s, gfpflags, node);
/* Then do expensive stuff like retrieving pages from the partial lists */
object = get_partial(s, gfpflags, node, c);
if (page) {
c = __this_cpu_ptr(s->cpu_slab);
if (c->page)
flush_slab(s, c);
if (unlikely(!object)) {
/*
* No other reference to the page yet so we can
* muck around with it freely without cmpxchg
*/
object = page->freelist;
page->freelist = NULL;
page->inuse = page->objects;
object = new_slab_objects(s, gfpflags, node, &c);
stat(s, ALLOC_SLAB);
c->node = page_to_nid(page);
c->page = page;
if (unlikely(!object)) {
if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
slab_out_of_memory(s, gfpflags, node);
if (kmem_cache_debug(s))
goto debug;
goto load_freelist;
local_irq_restore(flags);
return NULL;
}
}
if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
slab_out_of_memory(s, gfpflags, node);
local_irq_restore(flags);
return NULL;
debug:
if (!object || !alloc_debug_processing(s, page, object, addr))
goto new_slab;
if (likely(!kmem_cache_debug(s)))
goto load_freelist;
/* Only entered in the debug case */
if (!alloc_debug_processing(s, c->page, object, addr))
goto new_slab; /* Slab failed checks. Next slab needed */
c->freelist = get_freepointer(s, object);
deactivate_slab(s, c);
c->page = NULL;
c->node = NUMA_NO_NODE;
local_irq_restore(flags);
return object;
@ -2333,16 +2445,29 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
was_frozen = new.frozen;
new.inuse--;
if ((!new.inuse || !prior) && !was_frozen && !n) {
n = get_node(s, page_to_nid(page));
/*
* Speculatively acquire the list_lock.
* If the cmpxchg does not succeed then we may
* drop the list_lock without any processing.
*
* Otherwise the list_lock will synchronize with
* other processors updating the list of slabs.
*/
spin_lock_irqsave(&n->list_lock, flags);
if (!kmem_cache_debug(s) && !prior)
/*
* Slab was on no list before and will be partially empty
* We can defer the list move and instead freeze it.
*/
new.frozen = 1;
else { /* Needs to be taken off a list */
n = get_node(s, page_to_nid(page));
/*
* Speculatively acquire the list_lock.
* If the cmpxchg does not succeed then we may
* drop the list_lock without any processing.
*
* Otherwise the list_lock will synchronize with
* other processors updating the list of slabs.
*/
spin_lock_irqsave(&n->list_lock, flags);
}
}
inuse = new.inuse;
@ -2352,7 +2477,15 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
"__slab_free"));
if (likely(!n)) {
/*
/*
* If we just froze the page then put it onto the
* per cpu partial list.
*/
if (new.frozen && !was_frozen)
put_cpu_partial(s, page, 1);
/*
* The list lock was not taken therefore no list
* activity can be necessary.
*/
@ -2377,7 +2510,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
*/
if (unlikely(!prior)) {
remove_full(s, page);
add_partial(n, page, 1);
add_partial(n, page, DEACTIVATE_TO_TAIL);
stat(s, FREE_ADD_PARTIAL);
}
}
@ -2421,7 +2554,6 @@ static __always_inline void slab_free(struct kmem_cache *s,
slab_free_hook(s, x);
redo:
/*
* Determine the currently cpus per cpu slab.
* The cpu may change afterward. However that does not matter since
@ -2685,7 +2817,7 @@ static void early_kmem_cache_node_alloc(int node)
n = page->freelist;
BUG_ON(!n);
page->freelist = get_freepointer(kmem_cache_node, n);
page->inuse++;
page->inuse = 1;
page->frozen = 0;
kmem_cache_node->node[node] = n;
#ifdef CONFIG_SLUB_DEBUG
@ -2695,7 +2827,7 @@ static void early_kmem_cache_node_alloc(int node)
init_kmem_cache_node(n, kmem_cache_node);
inc_slabs_node(kmem_cache_node, node, page->objects);
add_partial(n, page, 0);
add_partial(n, page, DEACTIVATE_TO_HEAD);
}
static void free_kmem_cache_nodes(struct kmem_cache *s)
@ -2911,7 +3043,34 @@ static int kmem_cache_open(struct kmem_cache *s,
* The larger the object size is, the more pages we want on the partial
* list to avoid pounding the page allocator excessively.
*/
set_min_partial(s, ilog2(s->size));
set_min_partial(s, ilog2(s->size) / 2);
/*
* cpu_partial determined the maximum number of objects kept in the
* per cpu partial lists of a processor.
*
* Per cpu partial lists mainly contain slabs that just have one
* object freed. If they are used for allocation then they can be
* filled up again with minimal effort. The slab will never hit the
* per node partial lists and therefore no locking will be required.
*
* This setting also determines
*
* A) The number of objects from per cpu partial slabs dumped to the
* per node list when we reach the limit.
* B) The number of objects in cpu partial slabs to extract from the
* per node list when we run out of per cpu objects. We only fetch 50%
* to keep some capacity around for frees.
*/
if (s->size >= PAGE_SIZE)
s->cpu_partial = 2;
else if (s->size >= 1024)
s->cpu_partial = 6;
else if (s->size >= 256)
s->cpu_partial = 13;
else
s->cpu_partial = 30;
s->refcount = 1;
#ifdef CONFIG_NUMA
s->remote_node_defrag_ratio = 1000;
@ -2970,13 +3129,13 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page,
/*
* Attempt to free all partial slabs on a node.
* This is called from kmem_cache_close(). We must be the last thread
* using the cache and therefore we do not need to lock anymore.
*/
static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
{
unsigned long flags;
struct page *page, *h;
spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry_safe(page, h, &n->partial, lru) {
if (!page->inuse) {
remove_partial(n, page);
@ -2986,7 +3145,6 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
"Objects remaining on kmem_cache_close()");
}
}
spin_unlock_irqrestore(&n->list_lock, flags);
}
/*
@ -3020,6 +3178,7 @@ void kmem_cache_destroy(struct kmem_cache *s)
s->refcount--;
if (!s->refcount) {
list_del(&s->list);
up_write(&slub_lock);
if (kmem_cache_close(s)) {
printk(KERN_ERR "SLUB %s: %s called for cache that "
"still has objects.\n", s->name, __func__);
@ -3028,8 +3187,8 @@ void kmem_cache_destroy(struct kmem_cache *s)
if (s->flags & SLAB_DESTROY_BY_RCU)
rcu_barrier();
sysfs_slab_remove(s);
}
up_write(&slub_lock);
} else
up_write(&slub_lock);
}
EXPORT_SYMBOL(kmem_cache_destroy);
@ -3347,23 +3506,23 @@ int kmem_cache_shrink(struct kmem_cache *s)
* list_lock. page->inuse here is the upper limit.
*/
list_for_each_entry_safe(page, t, &n->partial, lru) {
if (!page->inuse) {
remove_partial(n, page);
discard_slab(s, page);
} else {
list_move(&page->lru,
slabs_by_inuse + page->inuse);
}
list_move(&page->lru, slabs_by_inuse + page->inuse);
if (!page->inuse)
n->nr_partial--;
}
/*
* Rebuild the partial list with the slabs filled up most
* first and the least used slabs at the end.
*/
for (i = objects - 1; i >= 0; i--)
for (i = objects - 1; i > 0; i--)
list_splice(slabs_by_inuse + i, n->partial.prev);
spin_unlock_irqrestore(&n->list_lock, flags);
/* Release empty slabs */
list_for_each_entry_safe(page, t, slabs_by_inuse, lru)
discard_slab(s, page);
}
kfree(slabs_by_inuse);
@ -4319,6 +4478,7 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
for_each_possible_cpu(cpu) {
struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
struct page *page;
if (!c || c->node < 0)
continue;
@ -4334,6 +4494,13 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
total += x;
nodes[c->node] += x;
}
page = c->partial;
if (page) {
x = page->pobjects;
total += x;
nodes[c->node] += x;
}
per_cpu[c->node]++;
}
}
@ -4412,11 +4579,12 @@ struct slab_attribute {
};
#define SLAB_ATTR_RO(_name) \
static struct slab_attribute _name##_attr = __ATTR_RO(_name)
static struct slab_attribute _name##_attr = \
__ATTR(_name, 0400, _name##_show, NULL)
#define SLAB_ATTR(_name) \
static struct slab_attribute _name##_attr = \
__ATTR(_name, 0644, _name##_show, _name##_store)
__ATTR(_name, 0600, _name##_show, _name##_store)
static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
{
@ -4485,6 +4653,27 @@ static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
}
SLAB_ATTR(min_partial);
static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
{
return sprintf(buf, "%u\n", s->cpu_partial);
}
static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
size_t length)
{
unsigned long objects;
int err;
err = strict_strtoul(buf, 10, &objects);
if (err)
return err;
s->cpu_partial = objects;
flush_all(s);
return length;
}
SLAB_ATTR(cpu_partial);
static ssize_t ctor_show(struct kmem_cache *s, char *buf)
{
if (!s->ctor)
@ -4523,6 +4712,37 @@ static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
}
SLAB_ATTR_RO(objects_partial);
static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
{
int objects = 0;
int pages = 0;
int cpu;
int len;
for_each_online_cpu(cpu) {
struct page *page = per_cpu_ptr(s->cpu_slab, cpu)->partial;
if (page) {
pages += page->pages;
objects += page->pobjects;
}
}
len = sprintf(buf, "%d(%d)", objects, pages);
#ifdef CONFIG_SMP
for_each_online_cpu(cpu) {
struct page *page = per_cpu_ptr(s->cpu_slab, cpu) ->partial;
if (page && len < PAGE_SIZE - 20)
len += sprintf(buf + len, " C%d=%d(%d)", cpu,
page->pobjects, page->pages);
}
#endif
return len + sprintf(buf + len, "\n");
}
SLAB_ATTR_RO(slabs_cpu_partial);
static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
{
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
@ -4845,6 +5065,8 @@ STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass);
STAT_ATTR(ORDER_FALLBACK, order_fallback);
STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail);
STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc);
STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free);
#endif
static struct attribute *slab_attrs[] = {
@ -4853,6 +5075,7 @@ static struct attribute *slab_attrs[] = {
&objs_per_slab_attr.attr,
&order_attr.attr,
&min_partial_attr.attr,
&cpu_partial_attr.attr,
&objects_attr.attr,
&objects_partial_attr.attr,
&partial_attr.attr,
@ -4865,6 +5088,7 @@ static struct attribute *slab_attrs[] = {
&destroy_by_rcu_attr.attr,
&shrink_attr.attr,
&reserved_attr.attr,
&slabs_cpu_partial_attr.attr,
#ifdef CONFIG_SLUB_DEBUG
&total_objects_attr.attr,
&slabs_attr.attr,
@ -4906,6 +5130,8 @@ static struct attribute *slab_attrs[] = {
&order_fallback_attr.attr,
&cmpxchg_double_fail_attr.attr,
&cmpxchg_double_cpu_fail_attr.attr,
&cpu_partial_alloc_attr.attr,
&cpu_partial_free_attr.attr,
#endif
#ifdef CONFIG_FAILSLAB
&failslab_attr.attr,
@ -5257,7 +5483,7 @@ static const struct file_operations proc_slabinfo_operations = {
static int __init slab_proc_init(void)
{
proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations);
return 0;
}
module_init(slab_proc_init);

10
tools/slub/slabinfo.c
View File

@ -42,6 +42,7 @@ struct slabinfo {
unsigned long deactivate_remote_frees, order_fallback;
unsigned long cmpxchg_double_cpu_fail, cmpxchg_double_fail;
unsigned long alloc_node_mismatch, deactivate_bypass;
unsigned long cpu_partial_alloc, cpu_partial_free;
int numa[MAX_NODES];
int numa_partial[MAX_NODES];
} slabinfo[MAX_SLABS];
@ -455,6 +456,11 @@ static void slab_stats(struct slabinfo *s)
s->alloc_from_partial * 100 / total_alloc,
s->free_remove_partial * 100 / total_free);
printf("Cpu partial list %8lu %8lu %3lu %3lu\n",
s->cpu_partial_alloc, s->cpu_partial_free,
s->cpu_partial_alloc * 100 / total_alloc,
s->cpu_partial_free * 100 / total_free);
printf("RemoteObj/SlabFrozen %8lu %8lu %3lu %3lu\n",
s->deactivate_remote_frees, s->free_frozen,
s->deactivate_remote_frees * 100 / total_alloc,
@ -1145,7 +1151,7 @@ static void read_slab_dir(void)
switch (de->d_type) {
case DT_LNK:
alias->name = strdup(de->d_name);
count = readlink(de->d_name, buffer, sizeof(buffer));
count = readlink(de->d_name, buffer, sizeof(buffer)-1);
if (count < 0)
fatal("Cannot read symlink %s\n", de->d_name);
@ -1209,6 +1215,8 @@ static void read_slab_dir(void)
slab->order_fallback = get_obj("order_fallback");
slab->cmpxchg_double_cpu_fail = get_obj("cmpxchg_double_cpu_fail");
slab->cmpxchg_double_fail = get_obj("cmpxchg_double_fail");
slab->cpu_partial_alloc = get_obj("cpu_partial_alloc");
slab->cpu_partial_free = get_obj("cpu_partial_free");
slab->alloc_node_mismatch = get_obj("alloc_node_mismatch");
slab->deactivate_bypass = get_obj("deactivate_bypass");
chdir("..");