On Thu, Sep 01 2016 at 5:17pm -0400, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > On Thu, Sep 01 2016 at 4:52pm -0400, > Bart Van Assche <bart.vanassche@xxxxxxxxxxx> wrote: > > > On 09/01/2016 01:48 PM, Mike Snitzer wrote: > > >Yeah, I since fixed that. Doesn't change the fact that your use of > > >blk_mq_freeze_queue() causes the 100% cpu usage. > > > > Hello Mike, > > > > Sorry but that doesn't make sense to me. blk_mq_freeze_queue() > > either returns quickly or waits. It cannot cause 100% CPU usage. > > Something else must be going on. If you can make the code available > > that you used in your test I will have a look at it. > > The suspend is hanging due the blk_mq_freeze_queue() -- and in turn the > resume (after reinstating paths) never happens. So no paths are > available. IO just keeps getting requeued, hence the 100% usage. > > The root of the problem is that the suspend isn't completing though. > > I've moved your work out to my private devel branch, see: > http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/log/?h=devel FYI I get the same 'dmsetup suspend --nolockfs --noflush mp' hang, running mptest's test_02_sdev_delete, when I try your unmodified patchset, see: http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/log/?h=devel.bart -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel