On Tue, 25 Jul 2017 21:12:17 -0700 "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > On Tue, Jul 25, 2017 at 09:02:33PM -0700, David Miller wrote: > > From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> > > Date: Tue, 25 Jul 2017 20:55:45 -0700 > > > > > On Tue, Jul 25, 2017 at 02:10:29PM -0700, David Miller wrote: > > >> Just to report, turning softlockup back on fixes things for me on > > >> sparc64 too. > > > > > > Very good! > > > > > >> The thing about softlockup is it runs an hrtimer, which seems to run > > >> about every 4 seconds. > > > > > > I could see where that could shake things loose, but I am surprised that > > > it would be needed. I ran a short run with CONFIG_SOFTLOCKUP_DETECTOR=y > > > with no trouble, but I will be running a longer test later on. > > > > > >> So I wonder if this is a NO_HZ problem. > > > > > > Might be. My tests run with NO_HZ_FULL=n and NO_HZ_IDLE=y. What are > > > you running? (Again, my symptoms are slightly different, so I might > > > be seeing a different bug.) > > > > I run with NO_HZ_FULL=n and NO_HZ_IDLE=y, just like you. > > > > To clarify, the symptoms show up with SOFTLOCKUP_DETECTOR disabled. > > Same here -- but my failure case happens fairly rarely, so it will take > some time to gain reasonable confidence that enabling SOFTLOCKUP_DETECTOR > had effect. > > But you are right, might be interesting to try NO_HZ_PERIODIC=y > or NO_HZ_FULL=y. So many possible tests, and so little time. ;-) > > Thanx, Paul > I'll be the headless chicken running around and trying as many tests as I can fit in. Typical time to see the failure for us is sub 10 minutes so we'll see how far we get. Make me a list to run if you like ;) NO_HZ_PERIODIC=y running now. Jonathan -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
