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From: Oleg Nesterov <oleg@tv-sign.ru>
To: paulmck@us.ibm.com
Cc: Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org, Roland McGrath <roland@redhat.com>,
	Linus Torvalds <torvalds@osdl.org>, Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH 1/2] fix kill_proc_info() vs CLONE_THREAD race
Date: Fri, 17 Feb 2006 00:16:31 +0300	[thread overview]
Message-ID: <43F4EBAF.D9BFEA13@tv-sign.ru> (raw)
In-Reply-To: 20060216191932.GE1296@us.ibm.com

"Paul E. McKenney" wrote:
> 
> > After that we don't need tasklist_lock to iterate over the thread
> > list, and we can simplify things, see for example do_sigaction()
> > or sys_times().
> 
> The above proposal would require that we hold siglock during the
> traversal, correct?

Yes, of course.

>                     Is that reasonable for non-signal-related traversals?
> Or were you thinking of making this change only for signal code?

Yes, I think it may be useful for non-signal-related traversals.

Currently we need tasklist_lock in order to use next_thread().
I beleive, we can migrate to rcu_read_lock+spinlock(sighand)
in most cases.

Well, next_thread() itself is safe already, but it can return
already zapped threads.

Oleg.

  reply	other threads:[~2006-02-16 19:58 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-02-06 16:45 [PATCH] fix kill_proc_info() vs copy_process() race Oleg Nesterov
2006-02-06 17:10 ` Oleg Nesterov
2006-02-06 20:25   ` Oleg Nesterov
2006-02-14 22:32 ` Paul E. McKenney
2006-02-15 14:05   ` Oleg Nesterov
2006-02-15 19:13     ` [PATCH 1/2] fix kill_proc_info() vs CLONE_THREAD race Oleg Nesterov
2006-02-16 19:19       ` Paul E. McKenney
2006-02-16 21:16         ` Oleg Nesterov [this message]
2006-02-15 19:13     ` [PATCH 2/2] fix kill_proc_info() vs fork() theoretical race Oleg Nesterov
2006-02-16 19:26       ` Paul E. McKenney
2006-02-16 20:56         ` Oleg Nesterov
2006-02-16 19:53           ` Paul E. McKenney
2006-02-16 21:20             ` Oleg Nesterov
2006-02-18  2:06               ` Paul E. McKenney
2006-02-18 18:19                 ` Oleg Nesterov
2006-02-20 17:49                   ` Paul E. McKenney

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