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. -- Jens Axboe
