Messages in this thread Patch in this message |  | | | From | Pekka Enberg <> | | Subject | [PATCH v2 2/2] SLUB: Mark merged slab caches in /proc/slabinfo | | Date | Tue, 14 Sep 2010 21:48:21 +0300 |
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SLUB uses the name of the first slab cache for all merged slab caches. To make the output of /proc/slabinfo more obvious, append the name of each merged slab cache to s->name.
An example output of /proc/slabinfo with this patch looks like this:
kmalloc-8192 544 544 8192 4 8 : tunables 0 kmalloc-4096+names_cache+biovec-256+sgpool-128+ecryptfs_headers kmalloc-2048+biovec-128+sgpool-64 400 416 2048 16 8 kmalloc-1024+biovec-64+sgpool-32 436 496 1024 16 4 : kmalloc-512+task_xstate+skbuff_fclone_cache+sgpool-16 1060 10 kmalloc-256+mnt_cache+skbuff_head_cache+biovec-16+sgpool-8+arp_ [ snip ] kmalloc-128+pid+bip-1+eventpoll_epi+request_sock_TCP+ip_mrt_cac kmalloc-64+fs_cache+biovec-4+blkdev_ioc+inet_peer_cache+tcp_bin kmalloc-32+ip_fib_alias+dnotify_struct+inotify_event_private_da kmalloc-16+biovec-1+ecryptfs_file_cache+dm_rq_clone_bio_info+dm kmalloc-8 5119 5120 8 512 1 : tunables 0 kmalloc-192+cred_jar+key_jar+filp+bip-4+bio-0+request_sock_TCPv kmalloc-96 924 1008 96 42 1 : tunables 0 kmem_cache_node 128 128 64 64 1 : tunables 0
Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@kernel.org> --- mm/slub.c | 37 +++++++++++++++++++++++++++++++++++++ 1 files changed, 37 insertions(+), 0 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index a31c033..77e4438 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3161,6 +3161,40 @@ void __init kmem_cache_init_late(void) } /* + * This limit is part of /proc/slabinfo ABI. It has never been enforced by the + * kernel but userspace programs such as "slabtop" expect it. + */ +#define MAX_SLAB_NAME_LEN 63 + +static int kmem_merge_names(struct kmem_cache *s, const char *name) +{ + size_t new_size; + char *new_name; + + if (strlen(s->name) >= MAX_SLAB_NAME_LEN) + return 0; + + /* Don't append name to merged name more than once */ + if (strstr(s->name, name)) + return 0; + + new_size = strlen(s->name) + strlen(name) + 2; + if (new_size > (MAX_SLAB_NAME_LEN + 1)) + new_size = MAX_SLAB_NAME_LEN + 1; /* NULL terminate */ + + new_name = kmalloc(new_size, GFP_KERNEL); + if (!new_name) + return -ENOMEM; + + snprintf(new_name, new_size, "%s+%s", s->name, name); + + kfree(s->name); + s->name = new_name; + + return 0; +} + +/* * Find a mergeable slab cache */ static int slab_unmergeable(struct kmem_cache *s) @@ -3233,6 +3267,9 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, down_write(&slub_lock); s = find_mergeable(size, align, flags, name, ctor); if (s) { + if (kmem_merge_names(s, name)) + goto err; + s->refcount++; /* * Adjust the object sizes so that we clear -- 1.6.3.3
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