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-rw-r--r--include/linux/slub_def.h1
-rw-r--r--mm/slub.c173
2 files changed, 92 insertions, 82 deletions
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index c2f8c8b..ebdcf4b 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -48,7 +48,6 @@ struct kmem_cache_cpu {
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];
#endif
diff --git a/mm/slub.c b/mm/slub.c
index 8c691fa..2de3c99 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1490,12 +1490,12 @@ 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.
+ * Remove slab from the partial list, freeze it and
+ * return the pointer to the freelist.
*
* Returns a list of objects or NULL if it fails.
*
- * Must hold list_lock.
+ * Must hold list_lock since we modify the partial list.
*/
static inline void *acquire_slab(struct kmem_cache *s,
struct kmem_cache_node *n, struct page *page,
@@ -1510,26 +1510,27 @@ static inline void *acquire_slab(struct kmem_cache *s,
* The old freelist is the list of objects for the
* per cpu allocation list.
*/
- do {
- freelist = page->freelist;
- counters = page->counters;
- new.counters = counters;
- if (mode) {
- new.inuse = page->objects;
- new.freelist = NULL;
- } else {
- new.freelist = freelist;
- }
+ freelist = page->freelist;
+ counters = page->counters;
+ new.counters = counters;
+ if (mode) {
+ new.inuse = page->objects;
+ new.freelist = NULL;
+ } else {
+ new.freelist = freelist;
+ }
- VM_BUG_ON(new.frozen);
- new.frozen = 1;
+ VM_BUG_ON(new.frozen);
+ new.frozen = 1;
- } while (!__cmpxchg_double_slab(s, page,
+ if (!__cmpxchg_double_slab(s, page,
freelist, counters,
new.freelist, new.counters,
- "lock and freeze"));
+ "acquire_slab"))
+ return NULL;
remove_partial(n, page);
+ WARN_ON(!freelist);
return freelist;
}
@@ -1563,7 +1564,6 @@ static void *get_partial_node(struct kmem_cache *s,
if (!object) {
c->page = page;
- c->node = page_to_nid(page);
stat(s, ALLOC_FROM_PARTIAL);
object = t;
available = page->objects - page->inuse;
@@ -1731,14 +1731,12 @@ void init_kmem_cache_cpus(struct kmem_cache *s)
/*
* Remove the cpu slab
*/
-static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
+static void deactivate_slab(struct kmem_cache *s, struct page *page, void *freelist)
{
enum slab_modes { M_NONE, M_PARTIAL, M_FULL, M_FREE };
- struct page *page = c->page;
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
int lock = 0;
enum slab_modes l = M_NONE, m = M_NONE;
- void *freelist;
void *nextfree;
int tail = DEACTIVATE_TO_HEAD;
struct page new;
@@ -1749,11 +1747,6 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
tail = DEACTIVATE_TO_TAIL;
}
- c->tid = next_tid(c->tid);
- c->page = NULL;
- freelist = c->freelist;
- c->freelist = NULL;
-
/*
* Stage one: Free all available per cpu objects back
* to the page freelist while it is still frozen. Leave the
@@ -2011,7 +2004,11 @@ int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
{
stat(s, CPUSLAB_FLUSH);
- deactivate_slab(s, c);
+ deactivate_slab(s, c->page, c->freelist);
+
+ c->tid = next_tid(c->tid);
+ c->page = NULL;
+ c->freelist = NULL;
}
/*
@@ -2055,10 +2052,10 @@ static void flush_all(struct kmem_cache *s)
* Check if the objects in a per cpu structure fit numa
* locality expectations.
*/
-static inline int node_match(struct kmem_cache_cpu *c, int node)
+static inline int node_match(struct page *page, int node)
{
#ifdef CONFIG_NUMA
- if (node != NUMA_NO_NODE && c->node != node)
+ if (node != NUMA_NO_NODE && page_to_nid(page) != node)
return 0;
#endif
return 1;
@@ -2130,10 +2127,16 @@ 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);
+ void *freelist;
+ struct kmem_cache_cpu *c = *pc;
+ struct page *page;
+
+ freelist = get_partial(s, flags, node, c);
+ if (freelist)
+ return freelist;
+
+ page = new_slab(s, flags, node);
if (page) {
c = __this_cpu_ptr(s->cpu_slab);
if (c->page)
@@ -2143,17 +2146,16 @@ static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
* No other reference to the page yet so we can
* muck around with it freely without cmpxchg
*/
- object = page->freelist;
+ freelist = page->freelist;
page->freelist = NULL;
stat(s, ALLOC_SLAB);
- c->node = page_to_nid(page);
c->page = page;
*pc = c;
} else
- object = NULL;
+ freelist = NULL;
- return object;
+ return freelist;
}
/*
@@ -2173,6 +2175,7 @@ static inline void *get_freelist(struct kmem_cache *s, struct page *page)
do {
freelist = page->freelist;
counters = page->counters;
+
new.counters = counters;
VM_BUG_ON(!new.frozen);
@@ -2206,7 +2209,8 @@ static inline void *get_freelist(struct kmem_cache *s, struct page *page)
static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
unsigned long addr, struct kmem_cache_cpu *c)
{
- void **object;
+ void *freelist;
+ struct page *page;
unsigned long flags;
local_irq_save(flags);
@@ -2219,25 +2223,29 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
c = this_cpu_ptr(s->cpu_slab);
#endif
- if (!c->page)
+ page = c->page;
+ if (!page)
goto new_slab;
redo:
- if (unlikely(!node_match(c, node))) {
+
+ if (unlikely(!node_match(page, node))) {
stat(s, ALLOC_NODE_MISMATCH);
- deactivate_slab(s, c);
+ deactivate_slab(s, page, c->freelist);
+ c->page = NULL;
+ c->freelist = NULL;
goto new_slab;
}
/* must check again c->freelist in case of cpu migration or IRQ */
- object = c->freelist;
- if (object)
+ freelist = c->freelist;
+ if (freelist)
goto load_freelist;
stat(s, ALLOC_SLOWPATH);
- object = get_freelist(s, c->page);
+ freelist = get_freelist(s, page);
- if (!object) {
+ if (!freelist) {
c->page = NULL;
stat(s, DEACTIVATE_BYPASS);
goto new_slab;
@@ -2246,50 +2254,50 @@ redo:
stat(s, ALLOC_REFILL);
load_freelist:
- c->freelist = get_freepointer(s, object);
+ /*
+ * freelist is pointing to the list of objects to be used.
+ * page is pointing to the page from which the objects are obtained.
+ * That page must be frozen for per cpu allocations to work.
+ */
+ VM_BUG_ON(!c->page->frozen);
+ c->freelist = get_freepointer(s, freelist);
c->tid = next_tid(c->tid);
local_irq_restore(flags);
- return object;
+ return freelist;
new_slab:
if (c->partial) {
- c->page = c->partial;
- c->partial = c->page->next;
- c->node = page_to_nid(c->page);
+ page = c->page = c->partial;
+ c->partial = page->next;
stat(s, CPU_PARTIAL_ALLOC);
c->freelist = NULL;
goto redo;
}
- /* Then do expensive stuff like retrieving pages from the partial lists */
- object = get_partial(s, gfpflags, node, c);
-
- if (unlikely(!object)) {
+ freelist = new_slab_objects(s, gfpflags, node, &c);
- object = new_slab_objects(s, gfpflags, node, &c);
+ if (unlikely(!freelist)) {
+ if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
+ slab_out_of_memory(s, gfpflags, node);
- if (unlikely(!object)) {
- if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
- slab_out_of_memory(s, gfpflags, node);
-
- local_irq_restore(flags);
- return NULL;
- }
+ local_irq_restore(flags);
+ return NULL;
}
+ page = c->page;
if (likely(!kmem_cache_debug(s)))
goto load_freelist;
/* Only entered in the debug case */
- if (!alloc_debug_processing(s, c->page, object, addr))
+ if (!alloc_debug_processing(s, page, freelist, addr))
goto new_slab; /* Slab failed checks. Next slab needed */
- c->freelist = get_freepointer(s, object);
- deactivate_slab(s, c);
- c->node = NUMA_NO_NODE;
+ deactivate_slab(s, page, get_freepointer(s, freelist));
+ c->page = NULL;
+ c->freelist = NULL;
local_irq_restore(flags);
- return object;
+ return freelist;
}
/*
@@ -2307,6 +2315,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
{
void **object;
struct kmem_cache_cpu *c;
+ struct page *page;
unsigned long tid;
if (slab_pre_alloc_hook(s, gfpflags))
@@ -2332,7 +2341,8 @@ redo:
barrier();
object = c->freelist;
- if (unlikely(!object || !node_match(c, node)))
+ page = c->page;
+ if (unlikely(!object || !node_match(page, node)))
object = __slab_alloc(s, gfpflags, node, addr, c);
@@ -4500,30 +4510,31 @@ 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);
- int node = ACCESS_ONCE(c->node);
+ int node;
struct page *page;
- if (node < 0)
- continue;
page = ACCESS_ONCE(c->page);
- if (page) {
- if (flags & SO_TOTAL)
- x = page->objects;
- else if (flags & SO_OBJECTS)
- x = page->inuse;
- else
- x = 1;
+ if (!page)
+ continue;
- total += x;
- nodes[node] += x;
- }
- page = c->partial;
+ node = page_to_nid(page);
+ if (flags & SO_TOTAL)
+ x = page->objects;
+ else if (flags & SO_OBJECTS)
+ x = page->inuse;
+ else
+ x = 1;
+ total += x;
+ nodes[node] += x;
+
+ page = ACCESS_ONCE(c->partial);
if (page) {
x = page->pobjects;
total += x;
nodes[node] += x;
}
+
per_cpu[node]++;
}
}
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