Messages in this thread | | | Subject | Re: PATCH: Fix race in cpu_down (hotplug cpu) | From | Nigel Cunningham <> | Date | Mon, 19 Sep 2005 16:11:11 +1000 |
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Hi.
On Mon, 2005-09-19 at 15:57, Srivatsa Vaddagiri wrote: > On Mon, Sep 19, 2005 at 01:31:27PM +0800, Shaohua Li wrote: > > A CPU is idle and then is preempted and starting offline CPU. After > > calling stop_machine_run, the CPU goes into idle and it will resume last > > idle loop. If the CPU is broken at specific point, then the CPU will > > continue executing previous idle and have no chance to call play_dead. > > Ok, that makes sense. Nigel, could you confirm which idle routine you are > using?
>From dmesg:
monitor/mwait feature present. using mwait in idle threads.
> > Am I missing anything? Nigel's patch seems can fix the situation for > > mwait_idle and poll_idle but can't fix for default_idle in i386 to me. > > I would say the right fix here is for poll_idle and mwait_idle (& similar > other idle routines) to monitor 'cpu_offline' flag in addition to need_resched > flag, rather than what Nigel has suggested.
Ok, but what about default_idle?
Regards,
Nigel
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