memcg: use generic slab iterators for showing slabinfo
Let's use generic slab_start/next/stop for showing memcg caches info. In
contrast to the current implementation, this will work even if all memcg
caches' info doesn't fit into a seq buffer (a page), plus it simply looks
neater.
Actually, the main reason I do this isn't mere cleanup. I'm going to zap
the memcg_slab_caches list, because I find it useless provided we have the
slab_caches list, and this patch is a step in this direction.
It should be noted that before this patch an attempt to read
memory.kmem.slabinfo of a cgroup that doesn't have kmem limit set resulted
in -EIO, while after this patch it will silently show nothing except the
header, but I don't think it will frustrate anyone.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 32e3b19..9d30129 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2547,26 +2547,6 @@
return cache_from_memcg_idx(cachep, memcg_cache_id(p->memcg));
}
-#ifdef CONFIG_SLABINFO
-static int mem_cgroup_slabinfo_read(struct seq_file *m, void *v)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
- struct memcg_cache_params *params;
-
- if (!memcg_kmem_is_active(memcg))
- return -EIO;
-
- print_slabinfo_header(m);
-
- mutex_lock(&memcg_slab_mutex);
- list_for_each_entry(params, &memcg->memcg_slab_caches, list)
- cache_show(memcg_params_to_cache(params), m);
- mutex_unlock(&memcg_slab_mutex);
-
- return 0;
-}
-#endif
-
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp,
unsigned long nr_pages)
{
@@ -4708,7 +4688,10 @@
#ifdef CONFIG_SLABINFO
{
.name = "kmem.slabinfo",
- .seq_show = mem_cgroup_slabinfo_read,
+ .seq_start = slab_start,
+ .seq_next = slab_next,
+ .seq_stop = slab_stop,
+ .seq_show = memcg_slab_show,
},
#endif
#endif