diff options
| -rw-r--r-- | mm/slub.c | 184 |
1 files changed, 181 insertions, 3 deletions
diff --git a/mm/slub.c b/mm/slub.c index 4251917c5da1..a6231963cae5 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -97,9 +97,6 @@ * * - Support PAGE_ALLOC_DEBUG. Should be easy to do. * - * - Support DEBUG_SLAB_LEAK. Trouble is we do not know where the full - * slabs are in SLUB. - * * - SLAB_DEBUG_INITIAL is not supported but I have never seen a use of * it. * @@ -2659,6 +2656,169 @@ static unsigned long validate_slab_cache(struct kmem_cache *s) return count; } +/* + * Generate lists of locations where slabcache objects are allocated + * and freed. + */ + +struct location { + unsigned long count; + void *addr; +}; + +struct loc_track { + unsigned long max; + unsigned long count; + struct location *loc; +}; + +static void free_loc_track(struct loc_track *t) +{ + if (t->max) + free_pages((unsigned long)t->loc, + get_order(sizeof(struct location) * t->max)); +} + +static int alloc_loc_track(struct loc_track *t, unsigned long max) +{ + struct location *l; + int order; + + if (!max) + max = PAGE_SIZE / sizeof(struct location); + + order = get_order(sizeof(struct location) * max); + + l = (void *)__get_free_pages(GFP_KERNEL, order); + + if (!l) + return 0; + + if (t->count) { + memcpy(l, t->loc, sizeof(struct location) * t->count); + free_loc_track(t); + } + t->max = max; + t->loc = l; + return 1; +} + +static int add_location(struct loc_track *t, struct kmem_cache *s, + void *addr) +{ + long start, end, pos; + struct location *l; + void *caddr; + + start = -1; + end = t->count; + + for ( ; ; ) { + pos = start + (end - start + 1) / 2; + + /* + * There is nothing at "end". If we end up there + * we need to add something to before end. + */ + if (pos == end) + break; + + caddr = t->loc[pos].addr; + if (addr == caddr) { + t->loc[pos].count++; + return 1; + } + + if (addr < caddr) + end = pos; + else + start = pos; + } + + /* + * Not found. Insert new tracking element + */ + if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max)) + return 0; + + l = t->loc + pos; + if (pos < t->count) + memmove(l + 1, l, + (t->count - pos) * sizeof(struct location)); + t->count++; + l->count = 1; + l->addr = addr; + return 1; +} + +static void process_slab(struct loc_track *t, struct kmem_cache *s, + struct page *page, enum track_item alloc) +{ + void *addr = page_address(page); + unsigned long map[BITS_TO_LONGS(s->objects)]; + void *p; + + bitmap_zero(map, s->objects); + for (p = page->freelist; p; p = get_freepointer(s, p)) + set_bit((p - addr) / s->size, map); + + for (p = addr; p < addr + s->objects * s->size; p += s->size) + if (!test_bit((p - addr) / s->size, map)) { + void *addr = get_track(s, p, alloc)->addr; + + add_location(t, s, addr); + } +} + +static int list_locations(struct kmem_cache *s, char *buf, + enum track_item alloc) +{ + int n = 0; + unsigned long i; + struct loc_track t; + int node; + + t.count = 0; + t.max = 0; + + /* Push back cpu slabs */ + flush_all(s); + + for_each_online_node(node) { + struct kmem_cache_node *n = get_node(s, node); + unsigned long flags; + struct page *page; + + if (!atomic_read(&n->nr_slabs)) + continue; + + spin_lock_irqsave(&n->list_lock, flags); + list_for_each_entry(page, &n->partial, lru) + process_slab(&t, s, page, alloc); + list_for_each_entry(page, &n->full, lru) + process_slab(&t, s, page, alloc); + spin_unlock_irqrestore(&n->list_lock, flags); + } + + for (i = 0; i < t.count; i++) { + void *addr = t.loc[i].addr; + + if (n > PAGE_SIZE - 100) + break; + n += sprintf(buf + n, "%7ld ", t.loc[i].count); + if (addr) + n += sprint_symbol(buf + n, (unsigned long)t.loc[i].addr); + else + n += sprintf(buf + n, "<not-available>"); + n += sprintf(buf + n, "\n"); + } + + free_loc_track(&t); + if (!t.count) + n += sprintf(buf, "No data\n"); + return n; +} + static unsigned long count_partial(struct kmem_cache_node *n) { unsigned long flags; @@ -3009,6 +3169,22 @@ static ssize_t validate_store(struct kmem_cache *s, } SLAB_ATTR(validate); +static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) +{ + if (!(s->flags & SLAB_STORE_USER)) + return -ENOSYS; + return list_locations(s, buf, TRACK_ALLOC); +} +SLAB_ATTR_RO(alloc_calls); + +static ssize_t free_calls_show(struct kmem_cache *s, char *buf) +{ + if (!(s->flags & SLAB_STORE_USER)) + return -ENOSYS; + return list_locations(s, buf, TRACK_FREE); +} +SLAB_ATTR_RO(free_calls); + #ifdef CONFIG_NUMA static ssize_t defrag_ratio_show(struct kmem_cache *s, char *buf) { @@ -3049,6 +3225,8 @@ static struct attribute * slab_attrs[] = { &poison_attr.attr, &store_user_attr.attr, &validate_attr.attr, + &alloc_calls_attr.attr, + &free_calls_attr.attr, #ifdef CONFIG_ZONE_DMA &cache_dma_attr.attr, #endif |