On Fri, 10 May 2019, Sasha Levin wrote: > On Fri, May 10, 2019 at 10:56:32AM -0700, Eric Wheeler wrote: > >From: Jens Axboe <[email protected]> > > > >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 <[email protected]> > >Tested-by: Kai Krakow <[email protected]> > >Reported-by: Paolo Valente <[email protected]> > >Fixes: f0635b8a416e ("bfq: calculate shallow depths at init time") > >Signed-off-by: Jens Axboe <[email protected]> > >Cc: [email protected] > > 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.
Thanks Sasha. We needed it for 4.19, I wasn't sure how far it would patch back so I left the version off. BFQ was merged in 4.12 iirc, so if it patched against 4.14, then 4.19 and 4.14 are the only ones that need it. -- Eric Wheeler > > -- > Thanks, > Sasha >
