From: Ingo Molnar <mingo@elte.hu>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>,
ebiederm@xmission.com, 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: Thu, 31 Jan 2008 14:32:35 +0100 [thread overview]
Message-ID: <20080131133235.GD8499@elte.hu> (raw)
In-Reply-To: <20080129150209.663538cb.akpm@linux-foundation.org>
* Andrew Morton <akpm@linux-foundation.org> 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.
we usually caught them via the DEBUG_PREEMPT checks on PREEMPT_RT: stuff
that has such implicit reliance tends to use smp_processor_id() along
the way and that gets flagged if the non-preemptability guarantee of
spin_lock() vanishes.
Ingo
next prev parent reply other threads:[~2008-01-31 13:33 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
2008-01-31 13:32 ` Ingo Molnar [this message]
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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