On Fri, Jul 17, 2020 at 3:44 AM Artur Paszkiewicz <artur.paszkiewicz@xxxxxxxxx> wrote: > > On 7/16/20 7:29 PM, Song Liu wrote: > > I just noticed another issue with this work on raid456, as iostat > > shows something > > like: > > > > Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s > > avgrq-sz avgqu-sz await r_await w_await svctm %util > > nvme0n1 6306.50 18248.00 636.00 1280.00 45.11 76.19 > > 129.65 3.03 1.23 0.67 1.51 0.76 145.50 > > nvme1n1 11441.50 13234.00 1069.50 961.00 71.87 55.39 > > 128.35 3.32 1.30 0.90 1.75 0.72 146.50 > > nvme2n1 8280.50 16352.50 971.50 1231.00 65.53 68.65 > > 124.77 3.20 1.17 0.69 1.54 0.64 142.00 > > nvme3n1 6158.50 18199.50 567.00 1453.50 39.81 76.74 > > 118.13 3.50 1.40 0.88 1.60 0.73 146.50 > > md0 0.00 0.00 1436.00 1411.00 89.75 88.19 > > 128.00 22.98 8.07 0.16 16.12 0.52 147.00 > > > > md0 here is a RAID-6 array with 4 devices. %util of > 100% is clearly > > wrong here. > > This only doesn't happen to RAID-0 or RAID-1 in my tests. > > > > Artur, could you please take a look at this? > > Hi Song, > > I think it's not caused by this patch, because %util of the member > drives is affected as well. I reverted the patch and it's still > happening: > > Device r/s rMB/s rrqm/s %rrqm r_await rareq-sz w/s wMB/s wrqm/s %wrqm w_await wareq-sz d/s dMB/s drqm/s %drqm d_await dareq-sz f/s f_await aqu-sz %util > md0 20.00 2.50 0.00 0.00 0.00 128.00 21.00 2.62 0.00 0.00 0.00 128.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 > nvme0n1 13.00 1.62 279.00 95.55 0.77 128.00 4.00 0.50 372.00 98.94 1289.00 128.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.17 146.70 > nvme1n1 15.00 1.88 310.00 95.38 0.53 128.00 21.00 2.62 341.00 94.20 1180.29 128.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 24.80 146.90 > nvme2n1 16.00 2.00 310.00 95.09 0.69 128.00 19.00 2.38 341.00 94.72 832.89 128.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 15.84 146.80 > nvme3n1 18.00 2.25 403.00 95.72 0.72 128.00 16.00 2.00 248.00 93.94 765.69 128.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 12.26 114.30 > > I was only able to reproduce it on a VM, it doesn't occur on real > hardware (for me). What was your test configuration? I was testing on VM. But I didn't see this issue after reverting the patch. Let me test more. Thanks, Song > Thanks, > Artur
