On Tue, Jul 22, 2014 at 09:21:40PM -0700, Linus Torvalds wrote: > On Tue, Jul 22, 2014 at 8:53 PM, Michel Dänzer <mic...@daenzer.net> wrote: > > > > Just happened again with the same change on top of 3.16-rc6. > > The (maybe) related bugzilla entry is just odd. Bruno Wolff reports > that the BUG_ON() in his added patch triggers: > > + cpumask_clear(sched_group_cpus(sg)); > + sg->sgc->capacity = 0; > + BUG_ON(!cpumask_empty(sched_group_cpus(sg))); > > where it *just* did a cpumask_clear(), and now the BUG_ON() triggers > that it's no longer empty? > > That would imply an allocation error, but all the sched groups seem to > be properly allocated with the proper addition of cpumask_size(). > > And his config file even has NR_CPUS being 32, so it should be a > single word of bitmap, which triggers all the simple code. > > Completely insane, in other words.
So we've had this other thread where the same happened: lkml.kernel.org/r/20140716145546.ga6...@wolff.to (pointed Michel to that earlier) And that seems to be sorted now (just found positive feedback in my Inbox this morning), it was a question of the arch code supplying completely 'broken' topology information, and the scheduler trusting it too much. The real fix in that thread is: lkml.kernel.org/r/20140722133514.gm12...@laptop.lan And I'll also add this to make the scheduler less trusting: lkml.kernel.org/r/20140722094740.gj12...@laptop.lan Michael, that's not going to tell us what's wrong with your machine, as you've not got the ancient dual P4 Xeon Bruno's got. Seeing how your cpuinfo says: model name : AMD A10-7850K Radeon R7, 12 Compute Cores 4C+8G but we can start the same debugging session I suppose. Could you run with this patch on top: lkml.kernel.org/r/20140718101633.gp9...@twins.programming.kicks-ass.net And provide us with the dmesg after boot? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
