From: Andrew Morton <akpm@linux-foundation.org>
To: Suren Baghdasaryan <surenb@google.com>
Cc: mhocko@kernel.org, rientjes@google.com, willy@infradead.org,
hannes@cmpxchg.org, guro@fb.com, riel@surriel.com,
minchan@kernel.org, christian@brauner.io, oleg@redhat.com,
timmurray@google.com, linux-api@vger.kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kernel-team@android.com, Minchan Kim <minchan@kernel.org>
Subject: Re: [PATCH 1/1] RFC: add pidfd_send_signal flag to reclaim mm while killing a process
Date: Fri, 13 Nov 2020 15:55:39 -0800 [thread overview]
Message-ID: <20201113155539.64e0af5b60ad3145b018ab0d@linux-foundation.org> (raw)
In-Reply-To: <20201113173448.1863419-1-surenb@google.com>
On Fri, 13 Nov 2020 09:34:48 -0800 Suren Baghdasaryan <surenb@google.com> wrote:
> When a process is being killed it might be in an uninterruptible sleep
> which leads to an unpredictable delay in its memory reclaim. In low memory
> situations, when it's important to free up memory quickly, such delay is
> problematic. Kernel solves this problem with oom-reaper thread which
> performs memory reclaim even when the victim process is not runnable.
> Userspace currently lacks such mechanisms and the need and potential
> solutions were discussed before (see links below).
> This patch provides a mechanism to perform memory reclaim in the context
> of the process that sends SIGKILL signal. New SYNC_REAP_MM flag for
> pidfd_send_signal syscall can be used only when sending SIGKILL signal
> and will lead to the caller synchronously reclaiming the memory that
> belongs to the victim and can be easily reclaimed.
hm.
Seems to me that the ability to reap another process's memory is a
generally useful one, and that it should not be tied to delivering a
signal in this fashion.
And we do have the new process_madvise(MADV_PAGEOUT). It may need a
few changes and tweaks, but can't that be used to solve this problem?
next prev parent reply other threads:[~2020-11-13 23:55 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-13 17:34 [PATCH 1/1] RFC: add pidfd_send_signal flag to reclaim mm while killing a process Suren Baghdasaryan
2020-11-13 23:55 ` Andrew Morton [this message]
2020-11-14 0:06 ` Suren Baghdasaryan
2020-11-14 1:00 ` Andrew Morton
2020-11-14 1:09 ` Suren Baghdasaryan
2020-11-14 1:18 ` Andrew Morton
2020-11-14 1:57 ` Suren Baghdasaryan
2020-11-14 2:16 ` Andrew Morton
2020-11-14 2:51 ` Suren Baghdasaryan
2020-11-16 23:24 ` Minchan Kim
2020-11-18 19:10 ` Michal Hocko
2020-11-18 19:22 ` Suren Baghdasaryan
2020-11-18 19:32 ` Michal Hocko
2020-11-18 19:51 ` Suren Baghdasaryan
2020-11-18 19:55 ` Suren Baghdasaryan
2020-11-19 0:13 ` Suren Baghdasaryan
2020-11-24 5:45 ` Suren Baghdasaryan
2020-11-18 10:32 ` Christian Brauner
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