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From: Oleg Nesterov <oleg@redhat.com>
To: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: lkml <linux-kernel@vger.kernel.org>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Bert Wesarg <bert.wesarg@googlemail.com>,
	Ingo Molnar <mingo@elte.hu>, Roland McGrath <roland@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: Strange stop-signal behavior in multithreaded program with defunct main
Date: Thu, 30 Oct 2008 12:00:00 +0100	[thread overview]
Message-ID: <20081030110000.GA3767@redhat.com> (raw)
In-Reply-To: <4907E6B9.8080700@gmail.com>

On 10/28, Michael Kerrisk wrote:
>
> Bert Wesarg described a scenario that I quickly replicated on
> 2.6.28-rc2 (and 2.6.25 -- it's not a regression in 2.6.28-rc)
> using the program below: if we have a multithreaded process
> with a defunct main thread running on a tty, and that
> process is sent a stop signal (either ^Z (SIGTSTP) or a stop
> signal sent from another terminal using kill(1)), then:
>
> a) the terminal is locked up; and
>
> b) the program is unresponsive to any other signal, except SIGKILL
> or SIGCONT.

Yes, known problem. Please look at

	[RFC,PATCH 3/3] do_wait: fix waiting for stopped group with dead leader
	http://marc.info/?t=119713920000003

Oleg.


  reply	other threads:[~2008-10-30  9:59 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-29  4:29 Strange stop-signal behavior in multithreaded program with defunct main Michael Kerrisk
2008-10-30 11:00 ` Oleg Nesterov [this message]
2008-10-30 15:55   ` Michael Kerrisk
2008-10-30 18:10     ` Oleg Nesterov

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