linux-kernel - Re: [PATCH 0/1] Add swappiness argument to memory.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]

Message-ID: <ZWjnnjX6Cg9ywXK2@dschatzberg-fedora-PF3DHTBV>
Date:   Thu, 30 Nov 2023 14:50:54 -0500
From:   Dan Schatzberg <schatzberg.dan@...il.com>
To:     Shakeel Butt <shakeelb@...gle.com>
Cc:     Johannes Weiner <hannes@...xchg.org>,
        Roman Gushchin <roman.gushchin@...ux.dev>,
        Yosry Ahmed <yosryahmed@...gle.com>, Huan Yang <link@...o.com>,
        linux-kernel@...r.kernel.org, cgroups@...r.kernel.org,
        linux-mm@...ck.org, Michal Hocko <mhocko@...nel.org>,
        Muchun Song <muchun.song@...ux.dev>,
        Andrew Morton <akpm@...ux-foundation.org>,
        David Hildenbrand <david@...hat.com>,
        Matthew Wilcox <willy@...radead.org>,
        Huang Ying <ying.huang@...el.com>,
        Kefeng Wang <wangkefeng.wang@...wei.com>,
        Peter Xu <peterx@...hat.com>,
        "Vishal Moola (Oracle)" <vishal.moola@...il.com>,
        Yue Zhao <findns94@...il.com>, Hugh Dickins <hughd@...gle.com>
Subject: Re: [PATCH 0/1] Add swappiness argument to memory.reclaim

On Thu, Nov 30, 2023 at 06:44:24PM +0000, Shakeel Butt wrote:
> [...]
> > * Swapout should be limited to manage SSD write endurance. In near-OOM
> 
> Is this about swapout to SSD only?

Correct

> >   situations we are fine with lots of swap-out to avoid OOMs. As these are
> >   typically rare events, they have relatively little impact on write endurance.
> >   However, proactive reclaim runs continuously and so its impact on SSD write
> >   endurance is more significant. Therefore it is desireable to control swap-out
> >   for proactive reclaim separately from reactive reclaim
> 
> This is understandable but swapout to zswap should be fine, right?
> (Sorry I am not following the discussion on zswap patches from Nhat. Is
> the answer there?)

You're correct here as well - we're not concerned about swapout to
zswap as that does not impact SSD write endurance. This is not related
to Nhat's patches.