Messages in this thread |  | | Date | Fri, 19 Feb 2016 22:32:48 -0800 | From | "Paul E. McKenney" <> | Subject | Re: rcu_preempt self-detected stall on CPU from 4.5-rc3, since 3.17 |
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On Sat, Feb 20, 2016 at 03:34:30PM +1100, Ross Green wrote: > On Sat, Feb 20, 2016 at 4:33 AM, Paul E. McKenney > <paulmck@linux.vnet.ibm.com> wrote: > > On Thu, Feb 18, 2016 at 08:13:18PM -0800, John Stultz wrote: > >> On Thu, Feb 18, 2016 at 7:56 PM, Ross Green <rgkernel@gmail.com> wrote: > >> > Well a bonus extra! > >> > Kept everything running and there was another stall. > >> > So i have included the demsg output for perusal. > >> > > >> > Just to clear things up there is no hotplug involved in this system. > >> > It is a standard Pandaboard ES Ti4460 two processor system. > >> > I use this for testing as a generic armv7 processor, plus can keep it > >> > just running along for testing for a long time. the system has a total > >> > of 23-25 process running on average. Mainly standard daemons. There is > >> > certainly no heavy processing going on. I run a series of benchmarks > >> > that are cpu intensive for the first 20 miinutes after boot and then > >> > just leave it idle away. checking every so often to see how it has > >> > gone. > >> > As mentioned I have observed these stalls going back to 3.17 kernel. > >> > It will often take up to a week to record such a stall. I will > >> > typically test every new release kernel, so the -rc? series will get > >> > around a weeks testing. > >> > >> Sorry. Kind of hopping in a bit late here. Is this always happening > >> with just the pandaboard? Or are you seeing this on different > >> machines? > >> > >> Have you tried enabling CONFIG_DEBUG_TIMEKEEPING just in case > >> something is going awry there? > > > > Excellent point -- timekeeping issues have caused this sort of issue > > in the past. > > > > Ross, on your next test, could you please enable CONFIG_DEBUG_TIMEKEEPING > > as John suggests? > > > > Thanx, Paul > > > As John has suggested have already enabled CONFIG_DEBUG_TIMEKEEPING. > > So far just on 1 day running. > > Sigh...!! Nothing to report as yet, only one day on the clock. > Its like watching grass grow!
I hear you! Though I was thinking in terms of watching paint dry...
Thanx, Paul
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