On Fri, Jan 25, 2019 at 09:30:49AM +0100, Johannes Thumshirn wrote: > On 25/01/2019 01:12, Liu Bo wrote: > > In fact the hang can be easily reproduced by the below script, > > > > H=/sys/fs/cgroup/unified/ > > P=/sys/fs/cgroup/unified/test > > > > echo "+io" > $H/cgroup.subtree_control > > mkdir -p $P > > > > echo $$ > $P/cgroup.procs > > > > xfs_io -f -d -c "pwrite 0 4k" /dev/sdg > > > > echo "`cat /sys/block/sdg/dev` target=1000000" > $P/io.latency > > > > xfs_io -f -d -c "pwrite 0 4k" /dev/sdg > > Can you please turn this into a testcase for blktests as well? > Sure, please check out the patch. https://patchwork.kernel.org/patch/10787361/ thanks, -liubo