linux-kernel - Re: [RFC PATCH v4 0/3] memcg weighted interleave mempolicy control

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:   Thu, 9 Nov 2023 22:48:56 +0000
From:   John Groves <john@...alactic.com>
To:     Gregory Price <gourry.memverge@...il.com>
Cc:     linux-kernel@...r.kernel.org 
        <linux-kernel@...r.kernel.org>,
        linux-cxl@...r.kernel.org 
        <linux-cxl@...r.kernel.org>,
        linux-mm@...ck.org 
        <linux-mm@...ck.org>,
        cgroups@...r.kernel.org 
        <cgroups@...r.kernel.org>,
        linux-doc@...r.kernel.org 
        <linux-doc@...r.kernel.org>,
        ying.huang@...el.com <ying.huang@...el.com>,
        akpm@...ux-foundation.org 
        <akpm@...ux-foundation.org>,
        mhocko@...nel.org <mhocko@...nel.org>,
        tj@...nel.org <tj@...nel.org>,
        lizefan.x@...edance.com 
        <lizefan.x@...edance.com>,
        hannes@...xchg.org <hannes@...xchg.org>,
        corbet@....net <corbet@....net>,
        roman.gushchin@...ux.dev 
        <roman.gushchin@...ux.dev>,
        shakeelb@...gle.com <shakeelb@...gle.com>,
        muchun.song@...ux.dev <muchun.song@...ux.dev>,
        Gregory Price <gregory.price@...verge.com>,
        jgroves@...ron.com <jgroves@...ron.com>
Subject: Re: [RFC PATCH v4 0/3] memcg weighted interleave mempolicy control

On 23/11/08 07:25PM, Gregory Price wrote:
> This patchset implements weighted interleave and adds a new cgroup
> sysfs entry: cgroup/memory.interleave_weights (excluded from root).

<snip>

We at Micron think this capability is really important, and moving it into
cgroups introduces important flexibility that was missing from prior versions
of the patchset.

To me this mainly represents the antidote to having system bios programming
the memory map to be heterogeneously interleaved - which I expect will be
an option, and some customers seem to want it. But that approach will affect
all apps (and also the kernel), and will hide at least the interleaved
numa nodes from Linux' view of the topology. There is a lot not to like
about that approach...

This approach checks all the important boxes: it only applies to apps where
it's enabled, the weighting can vary from one app to another, the
kernel is not affected, and the numa topology is not buried.

I see Michal's comment about cpuset vs. memory, and have no opinion there.

Thumbs up!
John Groves at Micron