linux-kernel - Re: [External] Re: [PATCH] cpuset: introduce non-blocking cpuset.mems setting option

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: <aDEdYIEpu_7o6Kot@slm.duckdns.org>
Date: Fri, 23 May 2025 15:14:08 -1000
From: Tejun Heo <tj@...nel.org>
To: Zhongkun He <hezhongkun.hzk@...edance.com>
Cc: Waiman Long <llong@...hat.com>, cgroups@...r.kernel.org,
	linux-kernel@...r.kernel.org, muchun.song@...ux.dev
Subject: Re: [External] Re: [PATCH] cpuset: introduce non-blocking
 cpuset.mems setting option

Hello,

On Sat, May 24, 2025 at 09:10:21AM +0800, Zhongkun He wrote:
...
> We move the task by modifying the cpuset.cpus and cpuset.mems and
> the memory migration is an option with cpuset.memory_migrate
> interface in V1. After we relocate the threads, the memory will be
> migrated by syscall move_pages in userspace slowly, within a few
> minutes.
> 
> Presently, cpuset.mems triggers synchronous memory migration,
> leading to prolonged and unacceptable service downtime in V2.
> 
> So we hope to add back an interface similar to cgroup v1, optional
> the migration.

Ah, I see, so it's not that you aren't migrating the memory but more that
the migration through cpuset.mems is too aggressive and causes disruption.
Is that the right understanding?

If so, would an interface to specify the rate of migration be a better
interface?

Thanks.

-- 
tejun