Messages in this thread | | | Date | Mon, 1 Oct 2012 20:14:23 +0800 | From | Fengguang Wu <> | Subject | Re: task_work_add/scheduler_tick: possible circular locking dependency detected |
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On Mon, Oct 01, 2012 at 02:05:15PM +0200, Ingo Molnar wrote: > > * Fengguang Wu <fengguang.wu@intel.com> wrote: > > > On Mon, Oct 01, 2012 at 12:50:39PM +0200, Peter Zijlstra wrote: > > > On Fri, 2012-09-28 at 19:34 +0800, Fengguang Wu wrote: > > > > Peter, > > > > > > > > I got the warning > > > > > > > > [ 10.412023] > > > > [ 10.412611] ====================================================== > > > > [ 10.413014] [ INFO: possible circular locking dependency detected ] > > > > [ 10.413014] 3.6.0-rc4-00098-g7eaffe9 #402 Not tainted > > > > [ 10.413014] ------------------------------------------------------- > > > > [ 10.413014] init/1 is trying to acquire lock: > > > > [ 10.413014] (&p->pi_lock){-.-.-.}, at: [<ffffffff81088214>] task_work_add+0x28/0x82 > > > > [ 10.413014] > > > > [ 10.413014] but task is already holding lock: > > > > [ 10.413014] (&rq->lock){-.-.-.}, at: [<ffffffff8109c6ea>] scheduler_tick+0x3f/0xec > > > > [ 10.413014] > > > > [ 10.413014] which lock already depends on the new lock. > > > > [ 10.413014] > > > > [ 10.413014] > > > > > > > > > > The commit ac3d0da8f3290b3d394cdb7f50604424a7cd6092 should avoid this > > > from happening, not sure what branch its on, but it was in tip before > > > all this landed, so I guess its due to you testing sched/numa branch and > > > not a merged branch like master or auto-next. > > > > Peter, you are right, it's tested in tip:sched/numa. linux-next is > > fine. Hmm, I should automatically test linux-next before raising the > > problem, hehe. > > tip:master is well-tested and generally a couple of days fresher > than linux-next, so in such a case where you are interested in > tip:sched/numa you should probably test tip:master.
OK, thanks for the tip!
Regards, Fengguang
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