On Tue, Nov 07, 2017 at 07:55:32PM -0700, Jens Axboe wrote: > On 11/07/2017 05:39 PM, Ming Lei wrote: > > On Tue, Nov 07, 2017 at 04:20:08PM +0000, Bart Van Assche wrote: > >> On Tue, 2017-11-07 at 10:11 +0800, Ming Lei wrote: > >>> If you can reproduce, please provide me at least the following log > >>> first: > >>> > >>> find /sys/kernel/debug/block -name tags | xargs cat | grep busy > >>> > >>> If any pending requests arn't completed, please provide the related > >>> info in dbgfs about where is the request. > >> > >> Every time I ran the above or a similar command its output was empty. I > >> assume that's because the hang usually occurs in a phase where these debugfs > >> attributes either have not yet been created or have already disappeared. > > > > Could you dump all tags? Then you can see if this attribute is disappeared. > > > > If that output is empty, it often means there isn't pending request not > > completed. So if that is true, your hang is _not_ related with RESTART. > > You need to check sched_tags as well. It could still be a restart race > or problem, if tags is empty but sched_tags has busy bits. Yeah, I didn't mention because SRP is MQ hardware, and the default scheduler is none, but if Bart changes that, the sched_tags need to checked first. -- Ming
