On Wed, Aug 03, 2016 at 09:16:31AM -0700, Paul E. McKenney wrote: > On Tue, Aug 02, 2016 at 01:45:04PM -0700, Paul E. McKenney wrote: > > On Tue, Aug 02, 2016 at 04:32:17PM -0400, Rich Felker wrote: > > > On Tue, Aug 02, 2016 at 12:48:02PM -0700, Paul E. McKenney wrote: > > [ . . . ] > > > > > Does the problem reproduces easily? > > > > > > Yes, it happens right after boot and repeats every 30-90 seconds or > > > so. > > > > Well, that at least makes it easier to test any patches! > > > > > > A bisection might be very helpful. > > > > > > Bisection would require some manual work to setup because the whole > > > reason I was rebasing on Linus's tree was to adapt the drivers to > > > upstream infrastructure changes (the new cpuhp stuff replacing > > > notifier for cpu starting). The unfortunate way it was done, each > > > driver adds an enum to linux/cpuhotplug.h so all the patches have > > > gratuitous conflicts. In addition, for older revisions in Linus's > > > tree, there's at least one show-stopping (hang during boot) bug that > > > needs a cherry-pick to fix. There may be other small issues too. I > > > don't think they're at all insurmountible but it requires an annoying > > > amount of scripting. > > > > I had to ask! Might eventually be necessary, but let's see what we > > can learn from what you currently have. > > And at first glance, my overnight run looks uglier than I would expect. > I am now running tests at v4.7, and will run other tests to see if > there really is a statistically significant degradation. If there is, > then I might be able to bisect, though with nine-hour runs this could > take quite some time.
Any more thoughts on this? I'm testing v4.8-rc5 (plus jcore drivers not yet upstream) and it's still happening. Rich
