Messages in this thread | | | Date | Thu, 20 Sep 2012 11:07:37 +0200 | Subject | Re: RCU lockup in the SMP idle thread, help... | From | Linus Walleij <> |
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On Thu, Sep 20, 2012 at 2:03 AM, Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:
> In the meantime, a crude fallback is for the CPU that detected the stall > to trace the stack of the task running on the other CPU. See below for > a crude (and untested) patch.
OK now I get this:
INFO: rcu_preempt detected stalls on CPUs/tasks: { 0} (detected by 1, t=29508 jiffies) Task dump for CPU 0: swapper/0 R running 0 0 0 0x00000000 [<c02da614>] (__schedule+0x238/0x52c) from [<c000f238>] (default_idle+0x28/0x30) [<c000f238>] (default_idle+0x28/0x30) from [<ffffffff>] (0xffffffff) INFO: rcu_preempt detected stalls on CPUs/tasks: { 0} (detected by 1, t=29851 jiffies) Task dump for CPU 0: swapper/0 R running 0 0 0 0x00000000 [<c02da614>] (__schedule+0x238/0x52c) from [<c000f238>] (default_idle+0x28/0x30) [<c000f238>] (default_idle+0x28/0x30) from [<ffffffff>] (0xffffffff)
So the swapper thread is the culprit? Hm, I'm not very smart with this no...
Yours, Linus Walleij
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