linux-kernel - Re: [PATCH v3] mm: memcg: Use larger batches for proactive reclaim

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon, 5 Feb 2024 22:16:34 +0100
From: Michal Hocko <mhocko@...e.com>
To: "T.J. Mercier" <tjmercier@...gle.com>
Cc: Johannes Weiner <hannes@...xchg.org>,
	Roman Gushchin <roman.gushchin@...ux.dev>,
	Shakeel Butt <shakeelb@...gle.com>,
	Muchun Song <muchun.song@...ux.dev>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Efly Young <yangyifei03@...ishou.com>, android-mm@...gle.com,
	yuzhao@...gle.com, mkoutny@...e.com,
	Yosry Ahmed <yosryahmed@...gle.com>, cgroups@...r.kernel.org,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] mm: memcg: Use larger batches for proactive reclaim

On Mon 05-02-24 12:47:47, T.J. Mercier wrote:
> On Mon, Feb 5, 2024 at 12:36 PM Michal Hocko <mhocko@...e.com> wrote:
[...]
> > This of something like
> > timeout $TIMEOUT echo $TARGET > $MEMCG_PATH/memory.reclaim
> > where timeout acts as a stop gap if the reclaim cannot finish in
> > TIMEOUT.
> 
> Yeah I get the desired behavior, but using sc->nr_reclaimed to achieve
> it is what's bothering me.

I am not really happy about this subtlety. If we have a better way then
let's do it. Better in its own patch, though.

> It's already wired up that way though, so if you want to make this
> change now then I can try to test for the difference using really
> large reclaim targets.

Yes, please. If you want it a separate patch then no objection from me
of course. If you do no like the nr_to_reclaim bailout then maybe we can
go with a simple break out flag in scan_control.

Thanks!
-- 
Michal Hocko
SUSE Labs