From: Michal Hocko <mhocko@suse.cz>
To: Vladimir Davydov <vdavydov@parallels.com>
Cc: akpm@linux-foundation.org, rientjes@google.com,
penberg@kernel.org, cl@linux.com, glommer@gmail.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
devel@openvz.org
Subject: Re: [PATCH 1/8] memcg: export kmemcg cache id via cgroup fs
Date: Tue, 4 Feb 2014 15:40:33 +0100 [thread overview]
Message-ID: <20140204144033.GE4890@dhcp22.suse.cz> (raw)
In-Reply-To: <570a97e4dfaded0939a9ddbea49055019dcc5803.1391356789.git.vdavydov@parallels.com>
On Sun 02-02-14 20:33:46, Vladimir Davydov wrote:
> Per-memcg kmem caches are named as follows:
>
> <global-cache-name>(<cgroup-kmem-id>:<cgroup-name>)
>
> where <cgroup-kmem-id> is the unique id of the memcg the cache belongs
> to, <cgroup-name> is the relative name of the memcg on the cgroup fs.
> Cache names are exposed to userspace for debugging purposes (e.g. via
> sysfs in case of slub or via dmesg).
If this is only for debugging purposes then it shouldn't pollute regular
memcg cgroupfs namespace.
> Using relative names makes it impossible in general (in case the cgroup
> hierarchy is not flat) to find out which memcg a particular cache
> belongs to, because <cgroup-kmem-id> is not known to the user. Since
> using absolute cgroup names would be an overkill,
I do not consider it an overkill. We are using the full path when
dumping OOM information so I do not see any reason this should be any
different.
> let's fix this by
> exporting the id of kmem-active memcg via cgroup fs file
> "memory.kmem.id".
>
> Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Nacked-by: Michal Hocko <mhocko@suse.cz>
> ---
> mm/memcontrol.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 53385cd4e6f0..91d242707404 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -3113,6 +3113,14 @@ int memcg_cache_id(struct mem_cgroup *memcg)
> return memcg ? memcg->kmemcg_id : -1;
> }
>
> +static s64 mem_cgroup_cache_id_read(struct cgroup_subsys_state *css,
> + struct cftype *cft)
> +{
> + struct mem_cgroup *memcg = mem_cgroup_from_css(css);
> +
> + return memcg_can_account_kmem(memcg) ? memcg_cache_id(memcg) : -1;
> +}
> +
> static size_t memcg_caches_array_size(int num_groups)
> {
> ssize_t size;
> @@ -6301,6 +6309,10 @@ static struct cftype mem_cgroup_files[] = {
> #endif
> #ifdef CONFIG_MEMCG_KMEM
> {
> + .name = "kmem.id",
> + .read_s64 = mem_cgroup_cache_id_read,
> + },
> + {
> .name = "kmem.limit_in_bytes",
> .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
> .write_string = mem_cgroup_write,
> --
> 1.7.10.4
>
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2014-02-04 14:40 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-02 16:33 [PATCH 0/8] memcg-vs-slab related fixes, improvements, cleanups Vladimir Davydov
2014-02-02 16:33 ` [PATCH 1/8] memcg: export kmemcg cache id via cgroup fs Vladimir Davydov
2014-02-03 6:21 ` David Rientjes
2014-02-03 6:57 ` Vladimir Davydov
2014-02-03 7:19 ` Vladimir Davydov
2014-02-03 10:05 ` Glauber Costa
2014-02-03 13:01 ` Vladimir Davydov
2014-02-03 11:04 ` David Rientjes
2014-02-03 13:00 ` Vladimir Davydov
2014-02-04 14:44 ` Michal Hocko
2014-02-04 14:40 ` Michal Hocko [this message]
2014-02-04 14:49 ` Vladimir Davydov
2014-02-02 16:33 ` [PATCH 2/8] memcg, slab: remove cgroup name from memcg cache names Vladimir Davydov
2014-02-04 14:45 ` Michal Hocko
2014-02-04 15:11 ` Vladimir Davydov
2014-02-04 15:13 ` Michal Hocko
2014-02-02 16:33 ` [PATCH 3/8] memcg, slab: never try to merge memcg caches Vladimir Davydov
2014-02-04 14:52 ` Michal Hocko
2014-02-04 14:59 ` Vladimir Davydov
2014-02-04 15:11 ` Michal Hocko
2014-02-04 15:27 ` Vladimir Davydov
2014-02-04 15:43 ` Glauber Costa
2014-02-04 16:04 ` Vladimir Davydov
2014-02-04 16:10 ` Glauber Costa
2014-02-06 14:07 ` Michal Hocko
2014-02-06 14:15 ` Vladimir Davydov
2014-02-06 15:29 ` Michal Hocko
2014-02-06 15:39 ` Vladimir Davydov
2014-02-02 16:33 ` [PATCH 4/8] memcg, slab: separate memcg vs root cache creation paths Vladimir Davydov
2014-02-02 16:33 ` [PATCH 5/8] slub: adjust memcg caches when creating cache alias Vladimir Davydov
2014-02-02 16:33 ` [PATCH 6/8] slub: rework sysfs layout for memcg caches Vladimir Davydov
2014-02-02 16:33 ` [PATCH 7/8] memcg, slab: unregister cache from memcg before starting to destroy it Vladimir Davydov
2014-02-02 16:33 ` [PATCH 8/8] memcg, slab: do not destroy children caches if parent has aliases Vladimir Davydov
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