From: Kirill Tkhai <ktkhai@virtuozzo.com>
To: Yang Shi <shy828301@gmail.com>,
guro@fb.com, vbabka@suse.cz, shakeelb@google.com,
david@fromorbit.com, hannes@cmpxchg.org, mhocko@suse.com,
akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [v7 PATCH 06/12] mm: vmscan: add shrinker_info_protected() helper
Date: Wed, 10 Feb 2021 15:12:39 +0300 [thread overview]
Message-ID: <73458559-f8b9-3f3a-6ffc-8fcc8a7dc519@virtuozzo.com> (raw)
In-Reply-To: <20210209174646.1310591-7-shy828301@gmail.com>
On 09.02.2021 20:46, Yang Shi wrote:
> The shrinker_info is dereferenced in a couple of places via rcu_dereference_protected
> with different calling conventions, for example, using mem_cgroup_nodeinfo helper
> or dereferencing memcg->nodeinfo[nid]->shrinker_info. And the later patch
> will add more dereference places.
>
> So extract the dereference into a helper to make the code more readable. No
> functional change.
>
> Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Kirill Tkhai <ktkhai@virtuozzo.com>
> ---
> mm/vmscan.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 9436f9246d32..273efbf4d53c 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -190,6 +190,13 @@ static int shrinker_nr_max;
> #define NR_MAX_TO_SHR_MAP_SIZE(nr_max) \
> (DIV_ROUND_UP(nr_max, BITS_PER_LONG) * sizeof(unsigned long))
>
> +static struct shrinker_info *shrinker_info_protected(struct mem_cgroup *memcg,
> + int nid)
> +{
> + return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info,
> + lockdep_is_held(&shrinker_rwsem));
> +}
> +
> static void free_shrinker_info_rcu(struct rcu_head *head)
> {
> kvfree(container_of(head, struct shrinker_info, rcu));
> @@ -202,8 +209,7 @@ static int expand_one_shrinker_info(struct mem_cgroup *memcg,
> int nid;
>
> for_each_node(nid) {
> - old = rcu_dereference_protected(
> - mem_cgroup_nodeinfo(memcg, nid)->shrinker_info, true);
> + old = shrinker_info_protected(memcg, nid);
> /* Not yet online memcg */
> if (!old)
> return 0;
> @@ -234,7 +240,7 @@ void free_shrinker_info(struct mem_cgroup *memcg)
>
> for_each_node(nid) {
> pn = mem_cgroup_nodeinfo(memcg, nid);
> - info = rcu_dereference_protected(pn->shrinker_info, true);
> + info = shrinker_info_protected(memcg, nid);
> kvfree(info);
> rcu_assign_pointer(pn->shrinker_info, NULL);
> }
> @@ -674,8 +680,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
> if (!down_read_trylock(&shrinker_rwsem))
> return 0;
>
> - info = rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info,
> - true);
> + info = shrinker_info_protected(memcg, nid);
> if (unlikely(!info))
> goto unlock;
>
>
next prev parent reply other threads:[~2021-02-10 12:18 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 17:46 [v7 PATCH 0/12] Make shrinker's nr_deferred memcg aware Yang Shi
2021-02-09 17:46 ` [v7 PATCH 01/12] mm: vmscan: use nid from shrink_control for tracepoint Yang Shi
2021-02-09 19:14 ` Shakeel Butt
2021-02-10 16:58 ` Yang Shi
2021-02-09 19:21 ` Roman Gushchin
2021-02-09 17:46 ` [v7 PATCH 02/12] mm: vmscan: consolidate shrinker_maps handling code Yang Shi
2021-02-09 20:27 ` Roman Gushchin
2021-02-10 14:19 ` Shakeel Butt
2021-02-09 17:46 ` [v7 PATCH 03/12] mm: vmscan: use shrinker_rwsem to protect shrinker_maps allocation Yang Shi
2021-02-09 20:33 ` Roman Gushchin
2021-02-09 23:28 ` Yang Shi
2021-02-09 17:46 ` [v7 PATCH 04/12] mm: vmscan: remove memcg_shrinker_map_size Yang Shi
2021-02-09 20:43 ` Roman Gushchin
2021-02-09 23:31 ` Yang Shi
2021-02-10 18:14 ` Vlastimil Babka
2021-02-09 17:46 ` [v7 PATCH 05/12] mm: memcontrol: rename shrinker_map to shrinker_info Yang Shi
2021-02-09 20:50 ` Roman Gushchin
2021-02-09 23:33 ` Yang Shi
2021-02-10 0:16 ` Roman Gushchin
2021-02-11 16:47 ` Kirill Tkhai
2021-02-11 17:29 ` Yang Shi
2021-02-09 17:46 ` [v7 PATCH 06/12] mm: vmscan: add shrinker_info_protected() helper Yang Shi
2021-02-10 0:22 ` Roman Gushchin
2021-02-10 1:07 ` Yang Shi
2021-02-10 1:29 ` Roman Gushchin
2021-02-10 12:12 ` Kirill Tkhai [this message]
2021-02-10 18:17 ` Vlastimil Babka
2021-02-12 6:54 ` [mm] bd741fb2ad: WARNING:suspicious_RCU_usage kernel test robot
2021-02-09 17:46 ` [v7 PATCH 07/12] mm: vmscan: use a new flag to indicate shrinker is registered Yang Shi
2021-02-10 0:39 ` Roman Gushchin
2021-02-10 1:12 ` Yang Shi
2021-02-10 1:34 ` Roman Gushchin
2021-02-10 1:55 ` Yang Shi
2021-02-10 18:45 ` Yang Shi
2021-02-10 18:23 ` Vlastimil Babka
2021-02-09 17:46 ` [v7 PATCH 08/12] mm: vmscan: add per memcg shrinker nr_deferred Yang Shi
2021-02-10 1:10 ` Roman Gushchin
2021-02-10 1:25 ` Yang Shi
2021-02-10 1:40 ` Roman Gushchin
2021-02-10 1:57 ` Yang Shi
2021-02-09 17:46 ` [v7 PATCH 09/12] mm: vmscan: use per memcg nr_deferred of shrinker Yang Shi
2021-02-10 1:27 ` Roman Gushchin
2021-02-10 1:52 ` Yang Shi
2021-02-10 14:36 ` Kirill Tkhai
2021-02-10 16:41 ` Yang Shi
2021-02-09 17:46 ` [v7 PATCH 10/12] mm: vmscan: don't need allocate shrinker->nr_deferred for memcg aware shrinkers Yang Shi
2021-02-10 1:23 ` Roman Gushchin
2021-02-09 17:46 ` [v7 PATCH 11/12] mm: memcontrol: reparent nr_deferred when memcg offline Yang Shi
2021-02-10 1:18 ` Roman Gushchin
2021-02-09 17:46 ` [v7 PATCH 12/12] mm: vmscan: shrink deferred objects proportional to priority Yang Shi
2021-02-11 13:10 ` Vlastimil Babka
2021-02-11 17:29 ` Yang Shi
2021-02-11 18:52 ` Vlastimil Babka
2021-02-11 19:15 ` Yang Shi
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=73458559-f8b9-3f3a-6ffc-8fcc8a7dc519@virtuozzo.com \
--to=ktkhai@virtuozzo.com \
--cc=akpm@linux-foundation.org \
--cc=david@fromorbit.com \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=shakeelb@google.com \
--cc=shy828301@gmail.com \
--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).