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mm, slub: split out allocations from pre/post hooks 

In the following patch we want to introduce CONFIG_SLUB_TINY allocation
paths that don't use the percpu slab. To prepare, refactor the
allocation functions:

Split out __slab_alloc_node() from slab_alloc_node() where the former
does the actual allocation and the latter calls the pre/post hooks.

Analogically, split out __kmem_cache_alloc_bulk() from
kmem_cache_alloc_bulk().

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
This commit is contained in:
Vlastimil Babka 2022-11-21 16:23:50 +01:00
parent fa9b88e459
commit 56d5a2b9ba
1 changed files with 80 additions and 50 deletions
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130
mm/slub.c
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@ -2907,10 +2907,10 @@ static unsigned long count_partial(struct kmem_cache_node *n,
}
#endif /* CONFIG_SLUB_DEBUG || SLAB_SUPPORTS_SYSFS */
#ifdef CONFIG_SLUB_DEBUG
static noinline void
slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
{
#ifdef CONFIG_SLUB_DEBUG
static DEFINE_RATELIMIT_STATE(slub_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
int node;
@ -2941,8 +2941,11 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
pr_warn(" node %d: slabs: %ld, objs: %ld, free: %ld\n",
node, nr_slabs, nr_objs, nr_free);
}
#endif
}
#else /* CONFIG_SLUB_DEBUG */
static inline void
slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) { }
#endif
static inline bool pfmemalloc_match(struct slab *slab, gfp_t gfpflags)
{
@ -3239,45 +3242,13 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
return p;
}
/*
* If the object has been wiped upon free, make sure it's fully initialized by
* zeroing out freelist pointer.
*/
static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s,
void *obj)
{
if (unlikely(slab_want_init_on_free(s)) && obj)
memset((void *)((char *)kasan_reset_tag(obj) + s->offset),
0, sizeof(void *));
}
/*
* Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
* have the fastpath folded into their functions. So no function call
* overhead for requests that can be satisfied on the fastpath.
*
* The fastpath works by first checking if the lockless freelist can be used.
* If not then __slab_alloc is called for slow processing.
*
* Otherwise we can simply pick the next object from the lockless free list.
*/
static __always_inline void *slab_alloc_node(struct kmem_cache *s, struct list_lru *lru,
static __always_inline void *__slab_alloc_node(struct kmem_cache *s,
gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
{
void *object;
struct kmem_cache_cpu *c;
struct slab *slab;
unsigned long tid;
struct obj_cgroup *objcg = NULL;
bool init = false;
s = slab_pre_alloc_hook(s, lru, &objcg, 1, gfpflags);
if (!s)
return NULL;
object = kfence_alloc(s, orig_size, gfpflags);
if (unlikely(object))
goto out;
void *object;
redo:
/*
@ -3347,6 +3318,48 @@ redo:
stat(s, ALLOC_FASTPATH);
}
return object;
}
/*
* If the object has been wiped upon free, make sure it's fully initialized by
* zeroing out freelist pointer.
*/
static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s,
void *obj)
{
if (unlikely(slab_want_init_on_free(s)) && obj)
memset((void *)((char *)kasan_reset_tag(obj) + s->offset),
0, sizeof(void *));
}
/*
* Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
* have the fastpath folded into their functions. So no function call
* overhead for requests that can be satisfied on the fastpath.
*
* The fastpath works by first checking if the lockless freelist can be used.
* If not then __slab_alloc is called for slow processing.
*
* Otherwise we can simply pick the next object from the lockless free list.
*/
static __always_inline void *slab_alloc_node(struct kmem_cache *s, struct list_lru *lru,
gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
{
void *object;
struct obj_cgroup *objcg = NULL;
bool init = false;
s = slab_pre_alloc_hook(s, lru, &objcg, 1, gfpflags);
if (!s)
return NULL;
object = kfence_alloc(s, orig_size, gfpflags);
if (unlikely(object))
goto out;
object = __slab_alloc_node(s, gfpflags, node, addr, orig_size);
maybe_wipe_obj_freeptr(s, object);
init = slab_want_init_on_alloc(gfpflags, s);
@ -3799,18 +3812,12 @@ void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
}
EXPORT_SYMBOL(kmem_cache_free_bulk);
/* Note that interrupts must be enabled when calling this function. */
int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
void **p)
static inline int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags,
size_t size, void **p, struct obj_cgroup *objcg)
{
struct kmem_cache_cpu *c;
int i;
struct obj_cgroup *objcg = NULL;
/* memcg and kmem_cache debug support */
s = slab_pre_alloc_hook(s, NULL, &objcg, size, flags);
if (unlikely(!s))
return false;
/*
* Drain objects in the per cpu slab, while disabling local
* IRQs, which protects against PREEMPT and interrupts
@ -3864,18 +3871,41 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
local_unlock_irq(&s->cpu_slab->lock);
slub_put_cpu_ptr(s->cpu_slab);
/*
* memcg and kmem_cache debug support and memory initialization.
* Done outside of the IRQ disabled fastpath loop.
*/
slab_post_alloc_hook(s, objcg, flags, size, p,
slab_want_init_on_alloc(flags, s));
return i;
error:
slub_put_cpu_ptr(s->cpu_slab);
slab_post_alloc_hook(s, objcg, flags, i, p, false);
kmem_cache_free_bulk(s, i, p);
return 0;
}
/* Note that interrupts must be enabled when calling this function. */
int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
void **p)
{
int i;
struct obj_cgroup *objcg = NULL;
if (!size)
return 0;
/* memcg and kmem_cache debug support */
s = slab_pre_alloc_hook(s, NULL, &objcg, size, flags);
if (unlikely(!s))
return 0;
i = __kmem_cache_alloc_bulk(s, flags, size, p, objcg);
/*
* memcg and kmem_cache debug support and memory initialization.
* Done outside of the IRQ disabled fastpath loop.
*/
if (i != 0)
slab_post_alloc_hook(s, objcg, flags, size, p,
slab_want_init_on_alloc(flags, s));
return i;
}
EXPORT_SYMBOL(kmem_cache_alloc_bulk);