diff options
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 109 |
1 files changed, 63 insertions, 46 deletions
diff --git a/mm/slub.c b/mm/slub.c index e87fd492a65b..f7368bfffb7a 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -354,7 +354,7 @@ static inline void *get_freepointer(struct kmem_cache *s, void *object) static void prefetch_freepointer(const struct kmem_cache *s, void *object) { - prefetch(object + s->offset); + prefetchw(object + s->offset); } static inline void *get_freepointer_safe(struct kmem_cache *s, void *object) @@ -414,6 +414,29 @@ static inline unsigned int oo_objects(struct kmem_cache_order_objects x) return x.x & OO_MASK; } +#ifdef CONFIG_SLUB_CPU_PARTIAL +static void slub_set_cpu_partial(struct kmem_cache *s, unsigned int nr_objects) +{ + unsigned int nr_pages; + + s->cpu_partial = nr_objects; + + /* + * We take the number of objects but actually limit the number of + * pages on the per cpu partial list, in order to limit excessive + * growth of the list. For simplicity we assume that the pages will + * be half-full. + */ + nr_pages = DIV_ROUND_UP(nr_objects * 2, oo_objects(s->oo)); + s->cpu_partial_pages = nr_pages; +} +#else +static inline void +slub_set_cpu_partial(struct kmem_cache *s, unsigned int nr_objects) +{ +} +#endif /* CONFIG_SLUB_CPU_PARTIAL */ + /* * Per slab locking using the pagelock */ @@ -2052,7 +2075,7 @@ static inline void remove_partial(struct kmem_cache_node *n, */ static inline void *acquire_slab(struct kmem_cache *s, struct kmem_cache_node *n, struct page *page, - int mode, int *objects) + int mode) { void *freelist; unsigned long counters; @@ -2068,7 +2091,6 @@ static inline void *acquire_slab(struct kmem_cache *s, freelist = page->freelist; counters = page->counters; new.counters = counters; - *objects = new.objects - new.inuse; if (mode) { new.inuse = page->objects; new.freelist = NULL; @@ -2106,9 +2128,8 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, { struct page *page, *page2; void *object = NULL; - unsigned int available = 0; unsigned long flags; - int objects; + unsigned int partial_pages = 0; /* * Racy check. If we mistakenly see no partial slabs then we @@ -2126,11 +2147,10 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, if (!pfmemalloc_match(page, gfpflags)) continue; - t = acquire_slab(s, n, page, object == NULL, &objects); + t = acquire_slab(s, n, page, object == NULL); if (!t) break; - available += objects; if (!object) { *ret_page = page; stat(s, ALLOC_FROM_PARTIAL); @@ -2138,10 +2158,15 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, } else { put_cpu_partial(s, page, 0); stat(s, CPU_PARTIAL_NODE); + partial_pages++; } +#ifdef CONFIG_SLUB_CPU_PARTIAL if (!kmem_cache_has_cpu_partial(s) - || available > slub_cpu_partial(s) / 2) + || partial_pages > s->cpu_partial_pages / 2) break; +#else + break; +#endif } spin_unlock_irqrestore(&n->list_lock, flags); @@ -2546,14 +2571,13 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) struct page *page_to_unfreeze = NULL; unsigned long flags; int pages = 0; - int pobjects = 0; local_lock_irqsave(&s->cpu_slab->lock, flags); oldpage = this_cpu_read(s->cpu_slab->partial); if (oldpage) { - if (drain && oldpage->pobjects > slub_cpu_partial(s)) { + if (drain && oldpage->pages >= s->cpu_partial_pages) { /* * Partial array is full. Move the existing set to the * per node partial list. Postpone the actual unfreezing @@ -2562,16 +2586,13 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) page_to_unfreeze = oldpage; oldpage = NULL; } else { - pobjects = oldpage->pobjects; pages = oldpage->pages; } } pages++; - pobjects += page->objects - page->inuse; page->pages = pages; - page->pobjects = pobjects; page->next = oldpage; this_cpu_write(s->cpu_slab->partial, page); @@ -3522,7 +3543,9 @@ static inline void free_nonslab_page(struct page *page, void *object) { unsigned int order = compound_order(page); - VM_BUG_ON_PAGE(!PageCompound(page), page); + if (WARN_ON_ONCE(!PageCompound(page))) + pr_warn_once("object pointer: 0x%p\n", object); + kfree_hook(object); mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B, -(PAGE_SIZE << order)); __free_pages(page, order); @@ -3989,6 +4012,8 @@ static void set_min_partial(struct kmem_cache *s, unsigned long min) static void set_cpu_partial(struct kmem_cache *s) { #ifdef CONFIG_SLUB_CPU_PARTIAL + unsigned int nr_objects; + /* * cpu_partial determined the maximum number of objects kept in the * per cpu partial lists of a processor. @@ -3998,24 +4023,22 @@ static void set_cpu_partial(struct kmem_cache *s) * 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. + * For backwards compatibility reasons, this is determined as number + * of objects, even though we now limit maximum number of pages, see + * slub_set_cpu_partial() */ if (!kmem_cache_has_cpu_partial(s)) - slub_set_cpu_partial(s, 0); + nr_objects = 0; else if (s->size >= PAGE_SIZE) - slub_set_cpu_partial(s, 2); + nr_objects = 6; else if (s->size >= 1024) - slub_set_cpu_partial(s, 6); + nr_objects = 24; else if (s->size >= 256) - slub_set_cpu_partial(s, 13); + nr_objects = 52; else - slub_set_cpu_partial(s, 30); + nr_objects = 120; + + slub_set_cpu_partial(s, nr_objects); #endif } @@ -4466,7 +4489,6 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page, { struct kmem_cache *s; unsigned int offset; - size_t object_size; bool is_kfence = is_kfence_address(ptr); ptr = kasan_reset_tag(ptr); @@ -4499,19 +4521,6 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page, n <= s->useroffset - offset + s->usersize) return; - /* - * If the copy is still within the allocated object, produce - * a warning instead of rejecting the copy. This is intended - * to be a temporary method to find any missing usercopy - * whitelists. - */ - object_size = slab_ksize(s); - if (usercopy_fallback && - offset <= object_size && n <= object_size - offset) { - usercopy_warn("SLUB object", s->name, to_user, offset, n); - return; - } - usercopy_abort("SLUB object", s->name, to_user, offset, n); } #endif /* CONFIG_HARDENED_USERCOPY */ @@ -5390,7 +5399,12 @@ SLAB_ATTR(min_partial); static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf) { - return sysfs_emit(buf, "%u\n", slub_cpu_partial(s)); + unsigned int nr_partial = 0; +#ifdef CONFIG_SLUB_CPU_PARTIAL + nr_partial = s->cpu_partial; +#endif + + return sysfs_emit(buf, "%u\n", nr_partial); } static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf, @@ -5461,12 +5475,12 @@ static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf) page = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu)); - if (page) { + if (page) pages += page->pages; - objects += page->pobjects; - } } + /* Approximate half-full pages , see slub_set_cpu_partial() */ + objects = (pages * oo_objects(s->oo)) / 2; len += sysfs_emit_at(buf, len, "%d(%d)", objects, pages); #ifdef CONFIG_SMP @@ -5474,9 +5488,12 @@ static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf) struct page *page; page = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu)); - if (page) + if (page) { + pages = READ_ONCE(page->pages); + objects = (pages * oo_objects(s->oo)) / 2; len += sysfs_emit_at(buf, len, " C%d=%d(%d)", - cpu, page->pobjects, page->pages); + cpu, objects, pages); + } } #endif len += sysfs_emit_at(buf, len, "\n"); |