From: Jan Engelhardt <jengelh@inai.de>
To: Suren Baghdasaryan <surenb@google.com>
Cc: Florian Weimer <fweimer@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@kernel.org>, Michal Hocko <mhocko@suse.com>,
David Rientjes <rientjes@google.com>,
Matthew Wilcox <willy@infradead.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Roman Gushchin <guro@fb.com>, Rik van Riel <riel@surriel.com>,
Minchan Kim <minchan@kernel.org>,
Christian Brauner <christian@brauner.io>,
Christoph Hellwig <hch@infradead.org>,
Oleg Nesterov <oleg@redhat.com>,
David Hildenbrand <david@redhat.com>,
Jann Horn <jannh@google.com>, Shakeel Butt <shakeelb@google.com>,
Tim Murray <timmurray@google.com>,
Linux API <linux-api@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
kernel-team <kernel-team@android.com>
Subject: Re: [PATCH 1/1] mm: introduce process_reap system call
Date: Mon, 12 Jul 2021 14:51:54 +0200 (CEST) [thread overview]
Message-ID: <q2s48op3-n660-p8r4-op50-po43r2249r24@vanv.qr> (raw)
In-Reply-To: <CAJuCfpFt55Dw1uW3S6_AincNfPaAtwdi6iXYVvFr7x3fvt4uzw@mail.gmail.com>
On Thursday 2021-07-08 08:05, Suren Baghdasaryan wrote:
>>
>> That explains very clearly the requirement, but it raises the question
>> why this isn't an si_code flag for rt_sigqueueinfo, reusing the existing
>> system call.
>
>I think you are suggesting to use sigqueue() to deliver the signal and
>perform the reaping when a special value accompanies it. This would be
>somewhat similar to my early suggestion to use a flag in
>pidfd_send_signal() (see:
>https://lore.kernel.org/patchwork/patch/1060407) to implement memory
>reaping which has another advantage of operation on PIDFDs instead of
>PIDs which can be recycled.
>kill()/pidfd_send_signal()/sigqueue() are supposed to deliver the
>signal and return without blocking. Changing that behavior was
>considered unacceptable in these discussions.
The way I understood the request is that a userspace program (or perhaps two,
if so desired) should issue _two_ calls, one to deliver the signal,
one to perform the reap portion:
uinfo.si_code = SI_QUEUE;
sigqueue(pid, SIGKILL, &uinfo);
uinfo.si_code = SI_REAP;
sigqueue(pid, SIGKILL, &uinfo);
next prev parent reply other threads:[~2021-07-12 13:00 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 19:28 [PATCH 1/1] mm: introduce process_reap system call Suren Baghdasaryan
2021-06-23 19:34 ` Suren Baghdasaryan
2021-06-29 13:13 ` Christian Brauner
2021-06-29 16:15 ` Suren Baghdasaryan
2021-06-30 18:00 ` Shakeel Butt
2021-06-30 18:43 ` Suren Baghdasaryan
2021-06-30 19:00 ` Shakeel Butt
2021-06-30 19:06 ` Suren Baghdasaryan
2021-06-30 18:26 ` Andy Lutomirski
2021-06-30 18:51 ` Suren Baghdasaryan
2021-06-30 21:45 ` Johannes Weiner
2021-07-01 0:44 ` Andy Lutomirski
2021-07-01 22:59 ` Suren Baghdasaryan
2021-07-02 15:27 ` Christian Brauner
2021-07-05 7:41 ` David Hildenbrand
2021-07-07 12:38 ` Michal Hocko
2021-07-07 21:14 ` Suren Baghdasaryan
2021-07-09 8:58 ` Christian Brauner
2021-07-09 20:05 ` Suren Baghdasaryan
2021-07-01 0:45 ` Andy Lutomirski
2021-07-01 23:08 ` Suren Baghdasaryan
2021-07-07 9:46 ` Florian Weimer
2021-07-07 21:07 ` Suren Baghdasaryan
2021-07-08 5:40 ` Florian Weimer
2021-07-08 6:05 ` Suren Baghdasaryan
2021-07-08 6:14 ` Florian Weimer
2021-07-08 6:39 ` Suren Baghdasaryan
2021-07-08 7:13 ` Florian Weimer
2021-07-12 12:51 ` Jan Engelhardt [this message]
2021-07-12 18:39 ` Suren Baghdasaryan
2021-07-12 19:16 ` Jan Engelhardt
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