From: Matthew Wilcox <willy@infradead.org>
To: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
tj@kernel.org, cl@linux.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
Jonathan Corbet <corbet@lwn.net>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH] Improve mutex documentation
Date: Thu, 15 Mar 2018 06:18:32 -0700 [thread overview]
Message-ID: <20180315131832.GC9949@bombadil.infradead.org> (raw)
In-Reply-To: <2397831d-71b5-3cc8-9dc4-ce06e2eddfde@virtuozzo.com>
On Thu, Mar 15, 2018 at 03:12:30PM +0300, Kirill Tkhai wrote:
> > +/**
> > + * mutex_lock_killable() - Acquire the mutex, interruptible by fatal signals.
>
> Shouldn't we clarify that fatal signals are SIGKILL only?
It's more complicated than it might seem (... welcome to signal handling!)
If you send SIGINT to a task that's waiting on a mutex_killable(), it will
still die. I *think* that's due to the code in complete_signal():
if (sig_fatal(p, sig) &&
!(signal->flags & SIGNAL_GROUP_EXIT) &&
!sigismember(&t->real_blocked, sig) &&
(sig == SIGKILL || !p->ptrace)) {
...
sigaddset(&t->pending.signal, SIGKILL);
You're correct that this code only checks for SIGKILL, but any fatal
signal will result in the signal group receiving SIGKILL.
Unless I've misunderstood, and it wouldn't be the first time I've
misunderstood signal handling.
next prev parent reply other threads:[~2018-03-15 13:18 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-14 11:51 [PATCH] percpu: Allow to kill tasks doing pcpu_alloc() and waiting for pcpu_balance_workfn() Kirill Tkhai
2018-03-14 13:55 ` Tejun Heo
2018-03-14 20:56 ` Andrew Morton
2018-03-14 22:09 ` Tejun Heo
2018-03-14 22:22 ` Andrew Morton
2018-03-15 8:58 ` Kirill Tkhai
2018-03-15 10:48 ` Tetsuo Handa
2018-03-15 12:09 ` Kirill Tkhai
2018-03-15 14:09 ` Tetsuo Handa
2018-03-15 14:42 ` Kirill Tkhai
2018-03-19 15:13 ` Tejun Heo
2018-03-15 11:58 ` [PATCH] Improve mutex documentation Matthew Wilcox
2018-03-15 12:12 ` Kirill Tkhai
2018-03-15 13:18 ` Matthew Wilcox [this message]
2018-03-15 13:23 ` Kirill Tkhai
2018-03-16 13:57 ` Peter Zijlstra
2018-03-19 15:14 ` [PATCH] percpu: Allow to kill tasks doing pcpu_alloc() and waiting for pcpu_balance_workfn() Tejun Heo
2018-03-19 15:32 ` [PATCH v2] mm: " Kirill Tkhai
2018-03-19 16:39 ` Tejun Heo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180315131832.GC9949@bombadil.infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=corbet@lwn.net \
--cc=ktkhai@virtuozzo.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mchehab@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox