From: Matthew Wilcox <willy@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Mina Almasry <almasrymina@google.com>,
Michal Hocko <mhocko@suse.com>, Theodore Ts'o <tytso@mit.edu>,
Greg Thelen <gthelen@google.com>,
Shakeel Butt <shakeelb@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
Roman Gushchin <songmuchun@bytedance.com>,
Johannes Weiner <hannes@cmpxchg.org>, Tejun Heo <tj@kernel.org>,
Vladimir Davydov <vdavydov.dev@gmail.com>,
riel@surriel.com, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org
Subject: Re: [PATCH v1 1/5] mm/shmem: support deterministic charging of tmpfs
Date: Mon, 8 Nov 2021 23:41:51 +0000 [thread overview]
Message-ID: <YYm1v25dLZL99qKK@casper.infradead.org> (raw)
In-Reply-To: <20211108221047.GE418105@dread.disaster.area>
On Tue, Nov 09, 2021 at 09:10:47AM +1100, Dave Chinner wrote:
> > + rcu_read_lock();
> > + memcg = rcu_dereference(mapping->host->i_sb->s_memcg_to_charge);
>
> Anything doing pointer chasing to obtain static, unchanging
> superblock state is poorly implemented. The s_memcg_to_charge value never
> changes, so this code should associate the memcg to charge directly
> on the mapping when the mapping is first initialised by the
> filesystem. We already do this with things like attaching address
> space ops and mapping specific gfp masks (i.e
> mapping_set_gfp_mask()), so this association should be set up that
> way, too (e.g. mapping_set_memcg_to_charge()).
I'm not a fan of enlarging struct address_space with another pointer
unless it's going to be used by all/most filesystems. If this is
destined to be a shmem-only feature, then it should be in the
shmem_inode instead of the mapping.
If we are to have this for all filesystems, then let's do that properly
and make it generic functionality from its introduction.
next prev parent reply other threads:[~2021-11-08 23:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20211108211959.1750915-1-almasrymina@google.com>
2021-11-08 21:19 ` [PATCH v1 1/5] mm/shmem: support deterministic charging of tmpfs Mina Almasry
2021-11-08 22:10 ` Dave Chinner
2021-11-08 23:41 ` Matthew Wilcox [this message]
2021-11-09 1:18 ` Dave Chinner
2021-11-09 23:56 ` Mina Almasry
2021-11-10 1:15 ` Mina Almasry
2021-11-15 17:53 ` Shakeel Butt
2021-11-09 1:15 ` Roman Gushchin
2021-11-08 21:19 ` [PATCH v1 2/5] mm: add tmpfs memcg= permissions check Mina Almasry
2021-11-08 21:19 ` [PATCH v1 3/5] mm/oom: handle remote ooms Mina Almasry
2021-11-09 1:19 ` Roman Gushchin
2021-11-08 21:19 ` [PATCH v1 4/5] mm, shmem: add tmpfs memcg= option documentation Mina Almasry
2021-11-08 21:19 ` [PATCH v1 5/5] mm, shmem, selftests: add tmpfs memcg= mount option tests Mina Almasry
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=YYm1v25dLZL99qKK@casper.infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=almasrymina@google.com \
--cc=cgroups@vger.kernel.org \
--cc=david@fromorbit.com \
--cc=gthelen@google.com \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=riel@surriel.com \
--cc=shakeelb@google.com \
--cc=songmuchun@bytedance.com \
--cc=tj@kernel.org \
--cc=tytso@mit.edu \
--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).