On Mon, Apr 25, 2022 at 11:39 PM Logan Gunthorpe <logang@xxxxxxxxxxxx> wrote: > > > > On 2022-04-24 02:00, Guoqing Jiang wrote: > > > > > > On 4/22/22 12:02 AM, Logan Gunthorpe wrote: > >> > >> On 2022-04-21 02:45, Xiao Ni wrote: > >>> Could you share the commands to get the test result (lock contention > >>> and performance)? > >> Sure. The performance we were focused on was large block writes. So we > >> setup raid5 instances with varying number of disks and ran the following > >> fio script directly on the drive. > >> > >> [simple] > >> filename=/dev/md0 > >> ioengine=libaio > >> rw=write > >> direct=1 > >> size=8G > >> blocksize=2m > >> iodepth=16 > >> runtime=30s > >> time_based=1 > >> offset_increment=8G > >> numjobs=12 > >>  > >> (We also played around with tuning this but didn't find substantial > >> changes once the bottleneck was hit) > > > > Nice, I suppose other IO patterns keep the same performance as before. > > > >> We tuned md with parameters like: > >> > >> echo 4 > /sys/block/md0/md/group_thread_cnt > >> echo 8192 > /sys/block/md0/md/stripe_cache_size > >> > >> For lock contention stats, we just used lockstat[1]; roughly like: > >> > >> echo 1 > /proc/sys/kernel/lock_stat > >> fio test.fio > >> echo 0 > /proc/sys/kernel/lock_stat > >> cat /proc/lock_stat > >> > >> And compared the before and after. > > > > Thanks for your effort, besides the performance test, please try to run > > mdadm test suites to avoid regression. > > Yeah, is there any documentation for that? I tried to look into it but > couldn't figure out how it's run. > > I do know that lkp-tests has run it on this series as I did get an error > from it. But while I'm pretty sure that error has been resolved, I was > never able to figure out how to run them locally. > Hi Logan You can clone the mdadm repo at git://git.kernel.org/pub/scm/utils/mdadm/mdadm.git Then you can find there is a script test under the directory. It's not under the tests directory. The test cases are under tests directory. Regards Xiao
