From: Shakeel Butt <shakeelb@google.com>
To: Roman Gushchin <guro@fb.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>, Linux MM <linux-mm@kvack.org>,
Vlastimil Babka <vbabka@suse.cz>,
Kernel Team <kernel-team@fb.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 09/19] mm: memcg/slab: charge individual slab objects instead of pages
Date: Mon, 22 Jun 2020 22:19:25 -0700 [thread overview]
Message-ID: <CALvZod4jchG_4gvigzb=iAoi1ytX6HVJe0xCp8b8=cc4NiXENg@mail.gmail.com> (raw)
In-Reply-To: <20200623015846.1141975-10-guro@fb.com>
On Mon, Jun 22, 2020 at 6:58 PM Roman Gushchin <guro@fb.com> wrote:
>
> Switch to per-object accounting of non-root slab objects.
>
> Charging is performed using obj_cgroup API in the pre_alloc hook.
> Obj_cgroup is charged with the size of the object and the size of
> metadata: as now it's the size of an obj_cgroup pointer. If the amount of
> memory has been charged successfully, the actual allocation code is
> executed. Otherwise, -ENOMEM is returned.
>
> In the post_alloc hook if the actual allocation succeeded, corresponding
> vmstats are bumped and the obj_cgroup pointer is saved. Otherwise, the
> charge is canceled.
>
> On the free path obj_cgroup pointer is obtained and used to uncharge the
> size of the releasing object.
>
> Memcg and lruvec counters are now representing only memory used by active
> slab objects and do not include the free space. The free space is shared
> and doesn't belong to any specific cgroup.
>
> Global per-node slab vmstats are still modified from
> (un)charge_slab_page() functions. The idea is to keep all slab pages
> accounted as slab pages on system level.
>
> Signed-off-by: Roman Gushchin <guro@fb.com>
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
> ---
[snip]
> +static inline struct kmem_cache *memcg_slab_pre_alloc_hook(struct kmem_cache *s,
> + struct obj_cgroup **objcgp,
> + size_t objects, gfp_t flags)
> +{
> + struct kmem_cache *cachep;
> +
> + cachep = memcg_kmem_get_cache(s, objcgp);
> + if (is_root_cache(cachep))
> + return s;
> +
> + if (obj_cgroup_charge(*objcgp, flags, objects * obj_full_size(s))) {
> + memcg_kmem_put_cache(cachep);
I think you forgot to put obj_cgroup_put(*objcgp) here again.
> + cachep = NULL;
> + }
> +
> + return cachep;
> +}
> +
After the above fix:
Reviewed-by: Shakeel Butt <shakeelb@google.com>
next prev parent reply other threads:[~2020-06-23 5:19 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 1:58 [PATCH v7 00/19] The new cgroup slab memory controller Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 01/19] mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state() Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 02/19] mm: memcg: prepare for byte-sized vmstat items Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 03/19] mm: memcg: convert vmstat slab counters to bytes Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 04/19] mm: slub: implement SLUB version of obj_to_index() Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 05/19] mm: memcontrol: decouple reference counting from page accounting Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 06/19] mm: memcg/slab: obj_cgroup API Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 07/19] mm: memcg/slab: allocate obj_cgroups for non-root slab pages Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 08/19] mm: memcg/slab: save obj_cgroup for non-root slab objects Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 09/19] mm: memcg/slab: charge individual slab objects instead of pages Roman Gushchin
2020-06-23 5:19 ` Shakeel Butt [this message]
2020-06-23 1:58 ` [PATCH v7 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 11/19] mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 12/19] mm: memcg/slab: use a single set of kmem_caches for all accounted allocations Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 13/19] mm: memcg/slab: simplify memcg cache creation Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 14/19] mm: memcg/slab: remove memcg_kmem_get_cache() Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 15/19] mm: memcg/slab: deprecate slab_root_caches Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 16/19] mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo() Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 17/19] mm: memcg/slab: use a single set of kmem_caches for all allocations Roman Gushchin
2020-06-23 5:25 ` Shakeel Butt
2020-06-23 1:58 ` [PATCH v7 18/19] kselftests: cgroup: add kernel memory accounting tests Roman Gushchin
2020-06-23 1:58 ` [PATCH v7 19/19] tools/cgroup: add memcg_slabinfo.py tool Roman Gushchin
2020-06-23 13:53 ` [PATCH v7 00/19] The new cgroup slab memory controller Vlastimil Babka
2020-06-23 15:39 ` Roman Gushchin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CALvZod4jchG_4gvigzb=iAoi1ytX6HVJe0xCp8b8=cc4NiXENg@mail.gmail.com' \
--to=shakeelb@google.com \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=vbabka@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).