提交 aceda773 编写于 作者: P Pekka Enberg

Merge branches 'slab/cleanups' and 'slab/fixes' into for-linus

......@@ -41,6 +41,8 @@ Possible debug options are
P Poisoning (object and padding)
U User tracking (free and alloc)
T Trace (please only use on single slabs)
O Switch debugging off for caches that would have
caused higher minimum slab orders
- Switch all debugging off (useful if the kernel is
configured with CONFIG_SLUB_DEBUG_ON)
......@@ -59,6 +61,14 @@ to the dentry cache with
slub_debug=F,dentry
Debugging options may require the minimum possible slab order to increase as
a result of storing the metadata (for example, caches with PAGE_SIZE object
sizes). This has a higher liklihood of resulting in slab allocation errors
in low memory situations or if there's high fragmentation of memory. To
switch off debugging for such caches by default, use
slub_debug=O
In case you forgot to enable debugging on the kernel command line: It is
possible to enable debugging manually when the kernel is up. Look at the
contents of:
......
......@@ -34,9 +34,4 @@ static __always_inline void *__kmalloc(size_t size, gfp_t flags)
return kmalloc(size, flags);
}
static inline void kmem_cache_init_late(void)
{
/* Nothing to do */
}
#endif /* __LINUX_SLOB_DEF_H */
......@@ -153,12 +153,10 @@ static __always_inline int kmalloc_index(size_t size)
if (size <= KMALLOC_MIN_SIZE)
return KMALLOC_SHIFT_LOW;
#if KMALLOC_MIN_SIZE <= 64
if (size > 64 && size <= 96)
if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
return 1;
if (size > 128 && size <= 192)
if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
return 2;
#endif
if (size <= 8) return 3;
if (size <= 16) return 4;
if (size <= 32) return 5;
......@@ -304,6 +302,4 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
}
#endif
void __init kmem_cache_init_late(void);
#endif /* _LINUX_SLUB_DEF_H */
......@@ -692,3 +692,8 @@ void __init kmem_cache_init(void)
{
slob_ready = 1;
}
void __init kmem_cache_init_late(void)
{
/* Nothing to do */
}
......@@ -140,6 +140,13 @@
#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
SLAB_POISON | SLAB_STORE_USER)
/*
* Debugging flags that require metadata to be stored in the slab. These get
* disabled when slub_debug=O is used and a cache's min order increases with
* metadata.
*/
#define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
/*
* Set of flags that will prevent slab merging
*/
......@@ -325,6 +332,7 @@ static int slub_debug;
#endif
static char *slub_debug_slabs;
static int disable_higher_order_debug;
/*
* Object debugging
......@@ -646,7 +654,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page)
slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
print_section("Padding", end - remainder, remainder);
restore_bytes(s, "slab padding", POISON_INUSE, start, end);
restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
return 0;
}
......@@ -976,6 +984,15 @@ static int __init setup_slub_debug(char *str)
*/
goto check_slabs;
if (tolower(*str) == 'o') {
/*
* Avoid enabling debugging on caches if its minimum order
* would increase as a result.
*/
disable_higher_order_debug = 1;
goto out;
}
slub_debug = 0;
if (*str == '-')
/*
......@@ -1026,7 +1043,7 @@ static unsigned long kmem_cache_flags(unsigned long objsize,
* Enable debugging if selected on the kernel commandline.
*/
if (slub_debug && (!slub_debug_slabs ||
strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0))
!strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))
flags |= slub_debug;
return flags;
......@@ -1109,8 +1126,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
}
if (kmemcheck_enabled
&& !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS)))
{
&& !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
int pages = 1 << oo_order(oo);
kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
......@@ -1560,6 +1576,10 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
"default order: %d, min order: %d\n", s->name, s->objsize,
s->size, oo_order(s->oo), oo_order(s->min));
if (oo_order(s->min) > get_order(s->objsize))
printk(KERN_WARNING " %s debugging increased min order, use "
"slub_debug=O to disable.\n", s->name);
for_each_online_node(node) {
struct kmem_cache_node *n = get_node(s, node);
unsigned long nr_slabs;
......@@ -2001,7 +2021,7 @@ static inline int calculate_order(int size)
return order;
fraction /= 2;
}
min_objects --;
min_objects--;
}
/*
......@@ -2400,6 +2420,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
* on bootup.
*/
align = calculate_alignment(flags, align, s->objsize);
s->align = align;
/*
* SLUB stores one object immediately after another beginning from
......@@ -2452,6 +2473,18 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
if (!calculate_sizes(s, -1))
goto error;
if (disable_higher_order_debug) {
/*
* Disable debugging flags that store metadata if the min slab
* order increased.
*/
if (get_order(s->size) > get_order(s->objsize)) {
s->flags &= ~DEBUG_METADATA_FLAGS;
s->offset = 0;
if (!calculate_sizes(s, -1))
goto error;
}
}
/*
* The larger the object size is, the more pages we want on the partial
......@@ -2790,6 +2823,11 @@ static s8 size_index[24] = {
2 /* 192 */
};
static inline int size_index_elem(size_t bytes)
{
return (bytes - 1) / 8;
}
static struct kmem_cache *get_slab(size_t size, gfp_t flags)
{
int index;
......@@ -2798,7 +2836,7 @@ static struct kmem_cache *get_slab(size_t size, gfp_t flags)
if (!size)
return ZERO_SIZE_PTR;
index = size_index[(size - 1) / 8];
index = size_index[size_index_elem(size)];
} else
index = fls(size - 1);
......@@ -3156,10 +3194,12 @@ void __init kmem_cache_init(void)
slab_state = PARTIAL;
/* Caches that are not of the two-to-the-power-of size */
if (KMALLOC_MIN_SIZE <= 64) {
if (KMALLOC_MIN_SIZE <= 32) {
create_kmalloc_cache(&kmalloc_caches[1],
"kmalloc-96", 96, GFP_NOWAIT);
caches++;
}
if (KMALLOC_MIN_SIZE <= 64) {
create_kmalloc_cache(&kmalloc_caches[2],
"kmalloc-192", 192, GFP_NOWAIT);
caches++;
......@@ -3186,17 +3226,28 @@ void __init kmem_cache_init(void)
BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
(KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;
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 == 128) {
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;
} else 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[(i - 1) / 8] = 8;
size_index[size_index_elem(i)] = 8;
}
slab_state = UP;
......@@ -4543,8 +4594,11 @@ static int sysfs_slab_add(struct kmem_cache *s)
}
err = sysfs_create_group(&s->kobj, &slab_attr_group);
if (err)
if (err) {
kobject_del(&s->kobj);
kobject_put(&s->kobj);
return err;
}
kobject_uevent(&s->kobj, KOBJ_ADD);
if (!unmergeable) {
/* Setup first alias */
......@@ -4726,7 +4780,7 @@ static const struct file_operations proc_slabinfo_operations = {
static int __init slab_proc_init(void)
{
proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
return 0;
}
module_init(slab_proc_init);
......
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