Messages in this thread | | | Date | Wed, 19 Feb 2014 12:57:47 +0100 | From | Peter Zijlstra <> | Subject | Re: [BUG] sched: tip/master show panic while booting/rebooting |
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On Wed, Feb 19, 2014 at 11:12:11AM +0800, Michael wang wrote: > On 02/18/2014 07:22 PM, Peter Zijlstra wrote: > > On Tue, Feb 18, 2014 at 01:12:03PM +0800, Michael wang wrote: > >> Hi, Folks > >> > >> Got below panic while testing tip/master on x86 box, it randomly > >> occur while booting or rebooting, any ideas? > > > > The obvious pick would be the relocation of the idle_balance call, but > > I'm not sure how that'll end up stalling. > > I've review the code again, seems like it was caused by the same issue > we discussed (RT/DL enqueued issue), I found that idle_balance() will > return 1 in such cases: > > /* > * While browsing the domains, we released the rq lock. > * A task could have be enqueued in the meantime > */ > if (this_rq->nr_running && !pulled_task) > return 1; > > And if no more fair task to be pulled, we will do balance again and > again in pick_next_task_fair() until panic in NMI... > > The solution we discussed could solve the problem I suppose, it was > already in progress, correct? > > Please let me know if there are any thing I could help with ;-)
Great, thanks!
Right, I'm waiting for Ingo to appear and commit some patches into tip.
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