/* Enable to test recovery from slab corruption on boot */
#undef SLUB_RESILIENCY_TEST
-#if PAGE_SHIFT <= 12
-
-/*
- * Small page size. Make sure that we do not fragment memory
- */
-#define DEFAULT_MAX_ORDER 1
-#define DEFAULT_MIN_OBJECTS 4
-
-#else
-
-/*
- * Large page machines are customarily able to handle larger
- * page orders.
- */
-#define DEFAULT_MAX_ORDER 2
-#define DEFAULT_MIN_OBJECTS 8
-
-#endif
-
/*
* Mininum number of partial slabs. These will be left on the partial
* lists even if they are empty. kmem_cache_shrink may reclaim them.
/* Internal SLUB flags */
#define __OBJECT_POISON 0x80000000 /* Poison object */
#define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
-#define __KMALLOC_CACHE 0x20000000 /* objects freed using kfree */
-#define __PAGE_ALLOC_FALLBACK 0x10000000 /* Allow fallback to page alloc */
/* Not all arches define cache_line_size */
#ifndef cache_line_size
}
/* Loop over all objects in a slab */
-#define for_each_object(__p, __s, __addr) \
- for (__p = (__addr); __p < (__addr) + (__s)->objects * (__s)->size;\
+#define for_each_object(__p, __s, __addr, __objects) \
+ for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
__p += (__s)->size)
/* Scan freelist */
return (p - addr) / s->size;
}
+static inline struct kmem_cache_order_objects oo_make(int order,
+ unsigned long size)
+{
+ struct kmem_cache_order_objects x = {
+ (order << 16) + (PAGE_SIZE << order) / size
+ };
+
+ return x;
+}
+
+static inline int oo_order(struct kmem_cache_order_objects x)
+{
+ return x.x >> 16;
+}
+
+static inline int oo_objects(struct kmem_cache_order_objects x)
+{
+ return x.x & ((1 << 16) - 1);
+}
+
#ifdef CONFIG_SLUB_DEBUG
/*
* Debug settings:
return 1;
start = page_address(page);
- length = (PAGE_SIZE << s->order);
+ length = (PAGE_SIZE << compound_order(page));
end = start + length;
remainder = length % s->size;
if (!remainder)
int nr = 0;
void *fp = page->freelist;
void *object = NULL;
+ unsigned long max_objects;
while (fp && nr <= page->objects) {
if (fp == search)
nr++;
}
+ max_objects = (PAGE_SIZE << compound_order(page)) / s->size;
+ if (max_objects > 65535)
+ max_objects = 65535;
+
+ if (page->objects != max_objects) {
+ slab_err(s, page, "Wrong number of objects. Found %d but "
+ "should be %d", page->objects, max_objects);
+ page->objects = max_objects;
+ slab_fix(s, "Number of objects adjusted.");
+ }
if (page->inuse != page->objects - nr) {
slab_err(s, page, "Wrong object count. Counter is %d but "
"counted were %d", page->inuse, page->objects - nr);
return atomic_long_read(&n->nr_slabs);
}
-static inline void inc_slabs_node(struct kmem_cache *s, int node)
+static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
{
struct kmem_cache_node *n = get_node(s, node);
* dilemma by deferring the increment of the count during
* bootstrap (see early_kmem_cache_node_alloc).
*/
- if (!NUMA_BUILD || n)
+ if (!NUMA_BUILD || n) {
atomic_long_inc(&n->nr_slabs);
+ atomic_long_add(objects, &n->total_objects);
+ }
}
-static inline void dec_slabs_node(struct kmem_cache *s, int node)
+static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
{
struct kmem_cache_node *n = get_node(s, node);
atomic_long_dec(&n->nr_slabs);
+ atomic_long_sub(objects, &n->total_objects);
}
/* Object debug checks for alloc/free paths */
static inline unsigned long slabs_node(struct kmem_cache *s, int node)
{ return 0; }
-static inline void inc_slabs_node(struct kmem_cache *s, int node) {}
-static inline void dec_slabs_node(struct kmem_cache *s, int node) {}
+static inline void inc_slabs_node(struct kmem_cache *s, int node,
+ int objects) {}
+static inline void dec_slabs_node(struct kmem_cache *s, int node,
+ int objects) {}
#endif
+
/*
* Slab allocation and freeing
*/
+static inline struct page *alloc_slab_page(gfp_t flags, int node,
+ struct kmem_cache_order_objects oo)
+{
+ int order = oo_order(oo);
+
+ if (node == -1)
+ return alloc_pages(flags, order);
+ else
+ return alloc_pages_node(node, flags, order);
+}
+
static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
{
struct page *page;
- int pages = 1 << s->order;
+ struct kmem_cache_order_objects oo = s->oo;
flags |= s->allocflags;
- if (node == -1)
- page = alloc_pages(flags, s->order);
- else
- page = alloc_pages_node(node, flags, s->order);
-
- if (!page)
- return NULL;
+ page = alloc_slab_page(flags | __GFP_NOWARN | __GFP_NORETRY, node,
+ oo);
+ if (unlikely(!page)) {
+ oo = s->min;
+ /*
+ * Allocation may have failed due to fragmentation.
+ * Try a lower order alloc if possible
+ */
+ page = alloc_slab_page(flags, node, oo);
+ if (!page)
+ return NULL;
- page->objects = s->objects;
+ stat(get_cpu_slab(s, raw_smp_processor_id()), ORDER_FALLBACK);
+ }
+ page->objects = oo_objects(oo);
mod_zone_page_state(page_zone(page),
(s->flags & SLAB_RECLAIM_ACCOUNT) ?
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
- pages);
+ 1 << oo_order(oo));
return page;
}
if (!page)
goto out;
- inc_slabs_node(s, page_to_nid(page));
+ inc_slabs_node(s, page_to_nid(page), page->objects);
page->slab = s;
page->flags |= 1 << PG_slab;
if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
start = page_address(page);
if (unlikely(s->flags & SLAB_POISON))
- memset(start, POISON_INUSE, PAGE_SIZE << s->order);
+ memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
last = start;
- for_each_object(p, s, start) {
+ for_each_object(p, s, start, page->objects) {
setup_object(s, page, last);
set_freepointer(s, last, p);
last = p;
static void __free_slab(struct kmem_cache *s, struct page *page)
{
- int pages = 1 << s->order;
+ int order = compound_order(page);
+ int pages = 1 << order;
if (unlikely(SlabDebug(page))) {
void *p;
slab_pad_check(s, page);
- for_each_object(p, s, page_address(page))
+ for_each_object(p, s, page_address(page),
+ page->objects)
check_object(s, page, p, 0);
ClearSlabDebug(page);
}
__ClearPageSlab(page);
reset_page_mapcount(page);
- __free_pages(page, s->order);
+ __free_pages(page, order);
}
static void rcu_free_slab(struct rcu_head *h)
static void discard_slab(struct kmem_cache *s, struct page *page)
{
- dec_slabs_node(s, page_to_nid(page));
+ dec_slabs_node(s, page_to_nid(page), page->objects);
free_slab(s, page);
}
c->page = new;
goto load_freelist;
}
-
- /*
- * No memory available.
- *
- * If the slab uses higher order allocs but the object is
- * smaller than a page size then we can fallback in emergencies
- * to the page allocator via kmalloc_large. The page allocator may
- * have failed to obtain a higher order page and we can try to
- * allocate a single page if the object fits into a single page.
- * That is only possible if certain conditions are met that are being
- * checked when a slab is created.
- */
- if (!(gfpflags & __GFP_NORETRY) &&
- (s->flags & __PAGE_ALLOC_FALLBACK)) {
- if (gfpflags & __GFP_WAIT)
- local_irq_enable();
- object = kmalloc_large(s->objsize, gfpflags);
- if (gfpflags & __GFP_WAIT)
- local_irq_disable();
- return object;
- }
return NULL;
debug:
if (!alloc_debug_processing(s, c->page, object, addr))
* take the list_lock.
*/
static int slub_min_order;
-static int slub_max_order = DEFAULT_MAX_ORDER;
-static int slub_min_objects = DEFAULT_MIN_OBJECTS;
+static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
+static int slub_min_objects = 4;
/*
* Merge control. If this is set then no merging of slab caches will occur.
init_tracking(kmalloc_caches, n);
#endif
init_kmem_cache_node(n);
- inc_slabs_node(kmalloc_caches, node);
+ inc_slabs_node(kmalloc_caches, node, page->objects);
/*
* lockdep requires consistent irq usage for each lock
* calculate_sizes() determines the order and the distribution of data within
* a slab object.
*/
-static int calculate_sizes(struct kmem_cache *s)
+static int calculate_sizes(struct kmem_cache *s, int forced_order)
{
unsigned long flags = s->flags;
unsigned long size = s->objsize;
unsigned long align = s->align;
+ int order;
/*
* Round up object size to the next word boundary. We can only
*/
size = ALIGN(size, align);
s->size = size;
+ if (forced_order >= 0)
+ order = forced_order;
+ else
+ order = calculate_order(size);
- if ((flags & __KMALLOC_CACHE) &&
- PAGE_SIZE / size < slub_min_objects) {
- /*
- * Kmalloc cache that would not have enough objects in
- * an order 0 page. Kmalloc slabs can fallback to
- * page allocator order 0 allocs so take a reasonably large
- * order that will allows us a good number of objects.
- */
- s->order = max(slub_max_order, PAGE_ALLOC_COSTLY_ORDER);
- s->flags |= __PAGE_ALLOC_FALLBACK;
- s->allocflags |= __GFP_NOWARN;
- } else
- s->order = calculate_order(size);
-
- if (s->order < 0)
+ if (order < 0)
return 0;
s->allocflags = 0;
- if (s->order)
+ if (order)
s->allocflags |= __GFP_COMP;
if (s->flags & SLAB_CACHE_DMA)
/*
* Determine the number of objects per slab
*/
- s->objects = (PAGE_SIZE << s->order) / size;
+ s->oo = oo_make(order, size);
+ s->min = oo_make(get_order(size), size);
+ if (oo_objects(s->oo) > oo_objects(s->max))
+ s->max = s->oo;
- return !!s->objects;
+ return !!oo_objects(s->oo);
}
s->align = align;
s->flags = kmem_cache_flags(size, flags, name, ctor);
- if (!calculate_sizes(s))
+ if (!calculate_sizes(s, -1))
goto error;
s->refcount = 1;
if (flags & SLAB_PANIC)
panic("Cannot create slab %s size=%lu realsize=%u "
"order=%u offset=%u flags=%lx\n",
- s->name, (unsigned long)size, s->size, s->order,
+ s->name, (unsigned long)size, s->size, oo_order(s->oo),
s->offset, flags);
return 0;
}
down_write(&slub_lock);
if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
- flags | __KMALLOC_CACHE, NULL))
+ flags, NULL))
goto panic;
list_add(&s->list, &slab_caches);
struct kmem_cache_node *n;
struct page *page;
struct page *t;
+ int objects = oo_objects(s->max);
struct list_head *slabs_by_inuse =
- kmalloc(sizeof(struct list_head) * s->objects, GFP_KERNEL);
+ kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
unsigned long flags;
if (!slabs_by_inuse)
if (!n->nr_partial)
continue;
- for (i = 0; i < s->objects; i++)
+ for (i = 0; i < objects; i++)
INIT_LIST_HEAD(slabs_by_inuse + i);
spin_lock_irqsave(&n->list_lock, flags);
* Rebuild the partial list with the slabs filled up most
* first and the least used slabs at the end.
*/
- for (i = s->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);
if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
return 1;
- if ((s->flags & __PAGE_ALLOC_FALLBACK))
- return 1;
-
if (s->ctor)
return 1;
}
#if (defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)) || defined(CONFIG_SLABINFO)
-static unsigned long count_partial(struct kmem_cache_node *n)
+static unsigned long count_partial(struct kmem_cache_node *n,
+ int (*get_count)(struct page *))
{
unsigned long flags;
unsigned long x = 0;
spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru)
- x += page->inuse;
+ x += get_count(page);
spin_unlock_irqrestore(&n->list_lock, flags);
return x;
}
+
+static int count_inuse(struct page *page)
+{
+ return page->inuse;
+}
+
+static int count_total(struct page *page)
+{
+ return page->objects;
+}
+
+static int count_free(struct page *page)
+{
+ return page->objects - page->inuse;
+}
#endif
#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
return 0;
}
- for_each_object(p, s, addr)
+ for_each_object(p, s, addr, page->objects)
if (!test_bit(slab_index(p, s, addr), map))
if (!check_object(s, page, p, 1))
return 0;
{
int node;
unsigned long count = 0;
- unsigned long *map = kmalloc(BITS_TO_LONGS(s->objects) *
+ unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
sizeof(unsigned long), GFP_KERNEL);
if (!map)
for_each_free_object(p, s, page->freelist)
set_bit(slab_index(p, s, addr), map);
- for_each_object(p, s, addr)
+ for_each_object(p, s, addr, page->objects)
if (!test_bit(slab_index(p, s, addr), map))
add_location(t, s, get_track(s, p, alloc));
}
}
enum slab_stat_type {
- SL_FULL,
- SL_PARTIAL,
- SL_CPU,
- SL_OBJECTS
+ SL_ALL, /* All slabs */
+ SL_PARTIAL, /* Only partially allocated slabs */
+ SL_CPU, /* Only slabs used for cpu caches */
+ SL_OBJECTS, /* Determine allocated objects not slabs */
+ SL_TOTAL /* Determine object capacity not slabs */
};
-#define SO_FULL (1 << SL_FULL)
+#define SO_ALL (1 << SL_ALL)
#define SO_PARTIAL (1 << SL_PARTIAL)
#define SO_CPU (1 << SL_CPU)
#define SO_OBJECTS (1 << SL_OBJECTS)
+#define SO_TOTAL (1 << SL_TOTAL)
static ssize_t show_slab_objects(struct kmem_cache *s,
char *buf, unsigned long flags)
{
unsigned long total = 0;
- int cpu;
int node;
int x;
unsigned long *nodes;
return -ENOMEM;
per_cpu = nodes + nr_node_ids;
- for_each_possible_cpu(cpu) {
- struct page *page;
- struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
+ if (flags & SO_CPU) {
+ int cpu;
- if (!c)
- continue;
+ for_each_possible_cpu(cpu) {
+ struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
- page = c->page;
- node = c->node;
- if (node < 0)
- continue;
- if (page) {
- if (flags & SO_CPU) {
- if (flags & SO_OBJECTS)
- x = page->inuse;
+ if (!c || c->node < 0)
+ continue;
+
+ if (c->page) {
+ if (flags & SO_TOTAL)
+ x = c->page->objects;
+ else if (flags & SO_OBJECTS)
+ x = c->page->inuse;
else
x = 1;
+
total += x;
- nodes[node] += x;
+ nodes[c->node] += x;
}
- per_cpu[node]++;
+ per_cpu[c->node]++;
}
}
- for_each_node_state(node, N_NORMAL_MEMORY) {
- struct kmem_cache_node *n = get_node(s, node);
+ if (flags & SO_ALL) {
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ if (flags & SO_TOTAL)
+ x = atomic_long_read(&n->total_objects);
+ else if (flags & SO_OBJECTS)
+ x = atomic_long_read(&n->total_objects) -
+ count_partial(n, count_free);
- if (flags & SO_PARTIAL) {
- if (flags & SO_OBJECTS)
- x = count_partial(n);
else
- x = n->nr_partial;
+ x = atomic_long_read(&n->nr_slabs);
total += x;
nodes[node] += x;
}
- if (flags & SO_FULL) {
- int full_slabs = atomic_long_read(&n->nr_slabs)
- - per_cpu[node]
- - n->nr_partial;
+ } else if (flags & SO_PARTIAL) {
+ for_each_node_state(node, N_NORMAL_MEMORY) {
+ struct kmem_cache_node *n = get_node(s, node);
- if (flags & SO_OBJECTS)
- x = full_slabs * s->objects;
+ if (flags & SO_TOTAL)
+ x = count_partial(n, count_total);
+ else if (flags & SO_OBJECTS)
+ x = count_partial(n, count_inuse);
else
- x = full_slabs;
+ x = n->nr_partial;
total += x;
nodes[node] += x;
}
}
-
x = sprintf(buf, "%lu", total);
#ifdef CONFIG_NUMA
for_each_node_state(node, N_NORMAL_MEMORY)
static int any_slab_objects(struct kmem_cache *s)
{
int node;
- int cpu;
-
- for_each_possible_cpu(cpu) {
- struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
-
- if (c && c->page)
- return 1;
- }
for_each_online_node(node) {
struct kmem_cache_node *n = get_node(s, node);
if (!n)
continue;
- if (n->nr_partial || atomic_long_read(&n->nr_slabs))
+ if (atomic_read(&n->total_objects))
return 1;
}
return 0;
static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", s->objects);
+ return sprintf(buf, "%d\n", oo_objects(s->oo));
}
SLAB_ATTR_RO(objs_per_slab);
+static ssize_t order_store(struct kmem_cache *s,
+ const char *buf, size_t length)
+{
+ int order = simple_strtoul(buf, NULL, 10);
+
+ if (order > slub_max_order || order < slub_min_order)
+ return -EINVAL;
+
+ calculate_sizes(s, order);
+ return length;
+}
+
static ssize_t order_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", s->order);
+ return sprintf(buf, "%d\n", oo_order(s->oo));
}
-SLAB_ATTR_RO(order);
+SLAB_ATTR(order);
static ssize_t ctor_show(struct kmem_cache *s, char *buf)
{
static ssize_t slabs_show(struct kmem_cache *s, char *buf)
{
- return show_slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU);
+ return show_slab_objects(s, buf, SO_ALL);
}
SLAB_ATTR_RO(slabs);
static ssize_t objects_show(struct kmem_cache *s, char *buf)
{
- return show_slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU|SO_OBJECTS);
+ return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
}
SLAB_ATTR_RO(objects);
+static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
+{
+ return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
+}
+SLAB_ATTR_RO(objects_partial);
+
+static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
+{
+ return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
+}
+SLAB_ATTR_RO(total_objects);
+
static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
{
return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
s->flags &= ~SLAB_RED_ZONE;
if (buf[0] == '1')
s->flags |= SLAB_RED_ZONE;
- calculate_sizes(s);
+ calculate_sizes(s, -1);
return length;
}
SLAB_ATTR(red_zone);
s->flags &= ~SLAB_POISON;
if (buf[0] == '1')
s->flags |= SLAB_POISON;
- calculate_sizes(s);
+ calculate_sizes(s, -1);
return length;
}
SLAB_ATTR(poison);
s->flags &= ~SLAB_STORE_USER;
if (buf[0] == '1')
s->flags |= SLAB_STORE_USER;
- calculate_sizes(s);
+ calculate_sizes(s, -1);
return length;
}
SLAB_ATTR(store_user);
STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
-
+STAT_ATTR(ORDER_FALLBACK, order_fallback);
#endif
static struct attribute *slab_attrs[] = {
&objs_per_slab_attr.attr,
&order_attr.attr,
&objects_attr.attr,
+ &objects_partial_attr.attr,
+ &total_objects_attr.attr,
&slabs_attr.attr,
&partial_attr.attr,
&cpu_slabs_attr.attr,
&deactivate_to_head_attr.attr,
&deactivate_to_tail_attr.attr,
&deactivate_remote_frees_attr.attr,
+ &order_fallback_attr.attr,
#endif
NULL
};
unsigned long nr_partials = 0;
unsigned long nr_slabs = 0;
unsigned long nr_inuse = 0;
- unsigned long nr_objs;
+ unsigned long nr_objs = 0;
+ unsigned long nr_free = 0;
struct kmem_cache *s;
int node;
nr_partials += n->nr_partial;
nr_slabs += atomic_long_read(&n->nr_slabs);
- nr_inuse += count_partial(n);
+ nr_objs += atomic_long_read(&n->total_objects);
+ nr_free += count_partial(n, count_free);
}
- nr_objs = nr_slabs * s->objects;
- nr_inuse += (nr_slabs - nr_partials) * s->objects;
+ nr_inuse = nr_objs - nr_free;
seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
- nr_objs, s->size, s->objects, (1 << s->order));
+ nr_objs, s->size, oo_objects(s->oo),
+ (1 << oo_order(s->oo)));
seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
0UL);