From: Waiman Long <longman@redhat.com>
To: Gang Li <gang.li@linux.dev>, Michal Hocko <mhocko@suse.com>
Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, rientjes@google.com,
Zefan Li <lizefan.x@bytedance.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] mm: oom: introduce cpuset oom
Date: Thu, 17 Aug 2023 12:45:43 -0400 [thread overview]
Message-ID: <0aa69b7b-8955-f495-0026-8c83597a4739@redhat.com> (raw)
In-Reply-To: <9ba0de31-b9b8-fb10-011e-b24e9dba5ccd@linux.dev>
On 8/17/23 04:40, Gang Li wrote:
>
> Since __GFP_HARDWALL is set as long as cpuset is enabled, I think we can
> use it to determine if we are under the constraint of CPUSET.
>
> But I have a question: Why we always set __GFP_HARDWALL when cpuset is
> enabled, regardless of the value of cpuset.mem_hardwall?
There is no direct dependency between cpuset.mem_hardwall and the
__GFP_HARDWALL flag. When cpuset is enabled, all user memory allocation
should be subjected to the cpuset memory constraint. In the case of
non-user memory allocation, it can fall back to to the node mask of an
ancestor up to the root cgroup, i.e. all memory nodes.
cpuset.mem_hardwall enables a barrier to this upward search.
Note that cpuset.mem_hardwall is a v1 feature that is not available in
cgroup v2.
Cheers,
Longman
next prev parent reply other threads:[~2023-08-17 16:45 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-11 6:58 Gang Li
2023-04-11 12:23 ` Michal Koutný
2023-04-11 13:04 ` Gang Li
2023-04-11 13:12 ` Michal Hocko
2023-04-11 13:17 ` Gang Li
2023-04-11 15:08 ` Michal Koutný
2023-04-11 14:36 ` Michal Hocko
2023-08-17 8:40 ` Gang Li
2023-08-17 16:45 ` Waiman Long [this message]
2023-08-22 6:31 ` Gang Li
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