From: Johannes Weiner <hannes@cmpxchg.org>
To: Muchun Song <songmuchun@bytedance.com>
Cc: guro@fb.com, mhocko@kernel.org, akpm@linux-foundation.org,
shakeelb@google.com, vdavydov.dev@gmail.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
duanxiongchun@bytedance.com
Subject: Re: [RFC PATCH 02/15] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm
Date: Fri, 2 Apr 2021 11:08:38 -0400 [thread overview]
Message-ID: <YGczdhFJNVphX8uj@cmpxchg.org> (raw)
In-Reply-To: <20210330101531.82752-3-songmuchun@bytedance.com>
On Tue, Mar 30, 2021 at 06:15:18PM +0800, Muchun Song wrote:
> When mm is NULL, we do not need to hold rcu lock and call css_tryget for
> the root memcg. And we also do not need to check !mm in every loop of
> while. So bail out early when !mm.
>
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Good observation.
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
next prev parent reply other threads:[~2021-04-02 15:08 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-30 10:15 [RFC PATCH 00/15] Use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-03-30 10:15 ` [RFC PATCH 01/15] mm: memcontrol: fix page charging in page replacement Muchun Song
2021-04-02 15:07 ` Johannes Weiner
2021-03-30 10:15 ` [RFC PATCH 02/15] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm Muchun Song
2021-04-02 15:08 ` Johannes Weiner [this message]
2021-03-30 10:15 ` [RFC PATCH 03/15] mm: memcontrol: remove the pgdata parameter of mem_cgroup_page_lruvec Muchun Song
2021-04-02 15:22 ` Johannes Weiner
2021-03-30 10:15 ` [RFC PATCH 04/15] mm: memcontrol: use lruvec_memcg in lruvec_holds_page_lru_lock Muchun Song
2021-04-02 16:21 ` Johannes Weiner
2021-04-03 12:37 ` [External] " Muchun Song
2021-03-30 10:15 ` [RFC PATCH 05/15] mm: memcontrol: simplify the logic of objcg pinning memcg Muchun Song
2021-03-30 10:15 ` [RFC PATCH 06/15] mm: memcontrol: move the objcg infrastructure out of CONFIG_MEMCG_KMEM Muchun Song
2021-03-30 10:15 ` [RFC PATCH 07/15] mm: memcontrol: introduce compact_lock_page_lruvec_irqsave Muchun Song
2021-03-30 10:15 ` [RFC PATCH 08/15] mm: memcontrol: make lruvec lock safe when the LRU pages reparented Muchun Song
2021-03-30 10:15 ` [RFC PATCH 09/15] mm: thp: introduce lock/unlock_split_queue{_irqsave}() Muchun Song
2021-03-30 10:15 ` [RFC PATCH 10/15] mm: thp: make deferred split queue lock safe when the LRU pages reparented Muchun Song
2021-03-30 10:15 ` [RFC PATCH 11/15] mm: memcontrol: make all the callers of page_memcg() safe Muchun Song
2021-03-30 10:15 ` [RFC PATCH 12/15] mm: memcontrol: introduce memcg_reparent_ops Muchun Song
2021-03-30 10:15 ` [RFC PATCH 13/15] mm: memcontrol: use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-03-30 10:15 ` [RFC PATCH 14/15] mm: memcontrol: rename {un}lock_page_memcg() to {un}lock_page_objcg() Muchun Song
2021-03-30 10:15 ` [RFC PATCH 15/15] mm: lru: add VM_BUG_ON_PAGE to lru maintenance function Muchun Song
2021-03-30 18:34 ` [RFC PATCH 00/15] Use obj_cgroup APIs to charge the LRU pages Shakeel Butt
2021-03-30 18:58 ` Roman Gushchin
2021-03-30 21:30 ` Johannes Weiner
2021-03-30 22:05 ` Roman Gushchin
2021-03-31 15:17 ` Johannes Weiner
2021-04-01 16:07 ` [External] " Muchun Song
2021-04-01 17:15 ` Shakeel Butt
2021-04-02 3:14 ` Muchun Song
2021-04-02 17:30 ` Johannes Weiner
2021-04-01 21:34 ` Roman Gushchin
2021-04-01 22:55 ` Yang Shi
2021-04-02 4:03 ` [External] " Muchun Song
2021-03-30 21:10 ` Johannes Weiner
2021-03-31 0:28 ` Shakeel Butt
2021-03-31 3:28 ` Balbir Singh
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=YGczdhFJNVphX8uj@cmpxchg.org \
--to=hannes@cmpxchg.org \
--cc=akpm@linux-foundation.org \
--cc=duanxiongchun@bytedance.com \
--cc=guro@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=shakeelb@google.com \
--cc=songmuchun@bytedance.com \
--cc=vdavydov.dev@gmail.com \
/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).