Messages in this thread | | | Date | Thu, 16 Aug 2012 10:03:56 -0400 | From | Dave Jones <> | Subject | Re: lockdep trace from posix timers |
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On Thu, Aug 16, 2012 at 08:54:31PM +0800, Ming Lei wrote: > On Sat, Jul 28, 2012 at 12:20 AM, Dave Jones <davej@redhat.com> wrote: > > On Tue, Jul 24, 2012 at 04:36:13PM -0400, Dave Jones wrote: > > > Linus tree as of 5fecc9d8f59e765c2a48379dd7c6f5cf88c7d75a > > > > > > Dave > > > > > > ====================================================== > > > [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ] > > > 3.5.0+ #122 Not tainted > > > ------------------------------------------------------ > > > trinity-child2/5327 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: > > > blocked: (tasklist_lock){.+.+..}, instance: ffffffff81c05098, at: [<ffffffff8109762b>] posix_cpu_timer_del+0x2b/0xe0 > > > > > > and this task is already holding: > > > blocked: (&(&new_timer->it_lock)->rlock){-.-...}, instance: ffff880143bce170, at: [<ffffffff81093d49>] __lock_timer+0x89/0x1f0 > > > which would create a new lock dependency: > > > (&(&new_timer->it_lock)->rlock){-.-...} -> (tasklist_lock){.+.+..} > > > > > > but this new dependency connects a HARDIRQ-irq-safe lock: > > > (&(&new_timer->it_lock)->rlock){-.-...} > > > ... which became HARDIRQ-irq-safe at: > > > > Shall I start bisecting this ? I can trigger it very easily, but if you > > can give me a set of commits to narrow down, it'll speed up the bisection. > > It should a real possible deadlock, could you test the below patch to > see if it can fix the warning?
I've not managed to hit it in a while. It seems very dependant upon specific builds for some reason. Very strange.
Dave
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