From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>,
ebiederm@xmission.com, mingo@elte.hu, paulmck@linux.vnet.ibm.com,
xemul@openvz.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fix tasklist + find_pid() with CONFIG_PREEMPT_RCU
Date: Wed, 30 Jan 2008 15:17:33 +0100 [thread overview]
Message-ID: <1201702653.28547.219.camel@lappy> (raw)
In-Reply-To: <20080129150209.663538cb.akpm@linux-foundation.org>
On Tue, 2008-01-29 at 15:02 -0800, Andrew Morton wrote:
> On Tue, 29 Jan 2008 19:40:19 +0300
> Oleg Nesterov <oleg@tv-sign.ru> wrote:
>
> > With CONFIG_PREEMPT_RCU read_lock(tasklist_lock) doesn't imply rcu_read_lock(),
>
> I'm suspecting that we have other code which assumes that read_lock, write_lock
> and spin_lock imply rcu_read_lock().
>
> I wonder if there are any sane runtime checks we can put in there to find
> such problems.
I have a lockdep annotation that finds rcu_dereference() usages outside
of rcu_read_lock().
Trouble is the amazing amount of output, I haven't come round to going
through it and annotation the false positives (think rcu safe library
routines called from contexts where the rcu capability is not used).
next prev parent reply other threads:[~2008-01-30 14:18 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-29 16:40 [PATCH] fix tasklist + find_pid() with CONFIG_PREEMPT_RCU Oleg Nesterov
2008-01-29 23:02 ` Andrew Morton
2008-01-30 14:17 ` Peter Zijlstra [this message]
2008-01-31 13:32 ` Ingo Molnar
2008-01-29 23:08 ` Andrew Morton
2008-01-30 2:16 ` Eric W. Biederman
2008-01-30 4:56 ` Paul E. McKenney
2008-01-30 3:24 ` Eric W. Biederman
2008-01-30 5:00 ` Paul E. McKenney
2008-01-30 9:20 ` Eric W. Biederman
2008-01-30 9:48 ` Oleg Nesterov
2008-01-30 9:30 ` Oleg Nesterov
2008-01-30 18:28 ` Eric W. Biederman
2008-01-31 9:31 ` Oleg Nesterov
-- strict thread matches above, loose matches on Subject: below --
2009-12-14 2:15 Tetsuo Handa
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