On Wed, Apr 12, 2017 at 06:11:25PM +0000, Bart Van Assche wrote: > On Wed, 2017-04-12 at 12:55 +0200, Benjamin Block wrote: > > On Fri, Apr 07, 2017 at 11:16:48AM -0700, Bart Van Assche wrote: > > > The six patches in this patch series fix the queue lockup I reported > > > recently on the linux-block mailing list. Please consider these patches > > > for inclusion in the upstream kernel. > > > > just out of curiosity. Is this maybe related to similar stuff happening > > when CPUs are hot plugged - at least in that the stack gets stuck? Like > > in this thread here: > > https://www.mail-archive.com/linux-block@xxxxxxxxxxxxxxx/msg06057.html > > > > Would be interesting, because we recently saw similar stuff happening. > > Hello Benjamin, > > My proposal is to repeat that test with Jens' for-next branch. If the issue > still occurs with that tree then please check the contents of > /sys/kernel/debug/block/*/mq/*/{dispatch,*/rq_list}. That will allow to > determine whether or not any block layer requests are still pending. If > running the command below resolves the deadlock then it means that a > trigger to run a block layer queue is still missing somewhere: > > for a in /sys/kernel/debug/block/*/mq/state; do echo run >$a; done > > See also git://git.kernel.dk/linux-block.git. > Thx for the hint! I'll forward that and see if the affected folks are willing to reproduce. Beste Grüße / Best regards, - Benjamin Block -- Linux on z Systems Development / IBM Systems & Technology Group IBM Deutschland Research & Development GmbH Vorsitz. AufsR.: Martina Koederitz / Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen / Registergericht: AmtsG Stuttgart, HRB 243294
