linux-kernel - Re: [PATCH 7/8] mm: memcontrol: consolidate lruvec stat flushing

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]

Message-ID: <YCFgr300eRiEZwpL@slm.duckdns.org>
Date:   Mon, 8 Feb 2021 11:02:55 -0500
From:   Tejun Heo <tj@...nel.org>
To:     Johannes Weiner <hannes@...xchg.org>
Cc:     Shakeel Butt <shakeelb@...gle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...e.com>, Roman Gushchin <guro@...com>,
        Linux MM <linux-mm@...ck.org>,
        Cgroups <cgroups@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Kernel Team <kernel-team@...com>
Subject: Re: [PATCH 7/8] mm: memcontrol: consolidate lruvec stat flushing

Hello,

On Mon, Feb 08, 2021 at 03:54:14PM -0500, Johannes Weiner wrote:
> We probably do need a better solution for the lruvecs as well, but in
> this case it just started holding up fixing the memory.stat issue for
> no reason and so I tabled it for another patch series.

rstat doesn't currently have a flush throttling mechanism cuz it doens't
expect readers to be super hot but adding one should be pretty easy - e.g.
it can just keep track of the number of updates on this cpu since the last
flush and then flush iff the it's above a certain threshold. Shouldn't be
too difficult to match or exceed the performance and error characteristics
of the existing code.

Thanks.

-- 
tejun