Re: [PATCH -mm 1/2] memcg: get rid of memcg_create_cache_name

From: Andrew Morton
Date: Wed May 07 2014 - 16:53:59 EST


On Wed, 7 May 2014 14:45:16 +0400 Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> wrote:

> @@ -3164,6 +3141,7 @@ void memcg_free_cache_params(struct kmem_cache *s)
> static void memcg_kmem_create_cache(struct mem_cgroup *memcg,
> struct kmem_cache *root_cache)
> {
> + static char *memcg_name_buf; /* protected by memcg_slab_mutex */
> struct kmem_cache *cachep;
> int id;
>
> @@ -3179,7 +3157,14 @@ static void memcg_kmem_create_cache(struct mem_cgroup *memcg,
> if (cache_from_memcg_idx(root_cache, id))
> return;
>
> - cachep = kmem_cache_create_memcg(memcg, root_cache);
> + if (!memcg_name_buf) {
> + memcg_name_buf = kmalloc(NAME_MAX + 1, GFP_KERNEL);
> + if (!memcg_name_buf)
> + return;
> + }

Does this have any meaningful advantage over the simpler

static char memcg_name_buf[NAME_MAX + 1];

?

I guess it saves a scrap of memory if the machine never uses memcg's.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/