On Sun, Oct 05, 2014 at 03:21:19PM -0400, Tejun Heo wrote: > On Sun, Oct 05, 2014 at 01:24:21PM -0400, Joe Lawrence wrote: > > Similar to the stop_machine deadlock scenario on !PREEMPT kernels > > addressed in b22ce2785d97 "workqueue: cond_resched() after processing > > each work item", kworker threads requeueing back-to-back with zero jiffy > > delay can stall RCU. The cond_resched call introduced in that fix will > > yield only iff there are other higher priority tasks to run, so force a > > quiescent RCU state between work items. > > > > Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxxx> > > Link: https://lkml.kernel.org/r/20140926105227.01325697@xxxxxxxxxxxxxxxxxxxxxxxxxxxx > > Link: https://lkml.kernel.org/r/20140929115445.40221d8e@xxxxxxxxxxxxxxxxxxxxxxxxxxxx > > Fixes: b22ce2785d97 ("workqueue: cond_resched() after processing each work item") > > Cc: <stable@xxxxxxxxxxxxxxx> > > Applied to wq/for-3.17-fixes. If 3.17 comes out before this gets > merged, I'll send it as for-3.18. Oops, the rcu calls aren't in mainline yet. I think it'd be best to route these through the RCU tree. Paul, can you please route these two patches? Acked-by: Tejun Heo <tj@xxxxxxxxxx> Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html