On Fri, May 10, 2019 at 04:18:55PM -0400, Sasha Levin wrote: > On Fri, May 10, 2019 at 10:56:32AM -0700, Eric Wheeler wrote: > > From: Jens Axboe <axboe@xxxxxxxxx> > > > > commit 77f1e0a52d26242b6c2dba019f6ebebfb9ff701e upstream > > > > A previous commit moved the shallow depth and BFQ depth map calculations > > to be done at init time, moving it outside of the hotter IO path. This > > potentially causes hangs if the users changes the depth of the scheduler > > map, by writing to the 'nr_requests' sysfs file for that device. > > > > Add a blk-mq-sched hook that allows blk-mq to inform the scheduler if > > the depth changes, so that the scheduler can update its internal state. > > > > Signed-off-by: Eric Wheeler <bfq@xxxxxxxxxxxxxxxxxx> > > Tested-by: Kai Krakow <kai@xxxxxxxxxxx> > > Reported-by: Paolo Valente <paolo.valente@xxxxxxxxxx> > > Fixes: f0635b8a416e ("bfq: calculate shallow depths at init time") > > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx > > I wasn't clear on what was backported here, so I've queued the upstream > version on 4.19 and 4.14, it doesn't seem to be relevant to older > branches. I only see this added to the 5.0 and 4.19 queues, did you forget to push the 4.14 update? thanks, greg k-h