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. Bart.
