https://bugzilla.suse.com/show_bug.cgi?id=1227180 https://bugzilla.suse.com/show_bug.cgi?id=1227180#c3 --- Comment #3 from Gabriel Krisman Bertazi <gabriel.bertazi@suse.com> --- In SP6, we have much more variation. Same machine, SP6. mitigations=auto: Hmean kIOPS 746353.26 ( 0.00%) 742246.48 ( -0.55%) 748464.20 ( 0.28%) 743324.07 ( -0.41%) 752230.04 ( 0.79%) 748760.59 ( 0.32%) 752005.82 ( 0.76%) 744865.18 ( -0.20%) 746811.71 ( 0.06%) 750949.33 ( 0.62%) Stddev kIOPS 718.33 ( 0.00%) 1927.17 (-168.28%) 756.26 ( -5.28%) 717.91 ( 0.06%) 816.84 ( -13.71%) 839.24 ( -16.83%) 982.03 ( -36.71%) 1491.61 (-107.65%) 1768.06 (-146.13%) 769.85 ( -7.17%) CoeffVar kIOPS 0.10 ( 0.00%) 0.26 (-169.77%) 0.10 ( -4.98%) 0.10 ( -0.35%) 0.11 ( -12.83%) 0.11 ( -16.46%) 0.13 ( -35.68%) 0.20 (-108.06%) 0.24 (-145.98%) 0.10 ( -6.52%) Note the results here are 25% worse than SP5. But the variation is still stable. I then disabled the mitigations: mitigations=off Hmean kIOPS 1539106.99 ( 0.00%) 1539732.55 ( 0.04%) 1538721.65 ( -0.03%) 1538612.99 ( -0.03%) 1537466.46 ( -0.11%) 1538740.83 ( -0.02%) 1539686.30 ( 0.04%) 1540408.73 ( 0.08%) 1538587.63 ( -0.03%) 1538455.36 ( -0.04%) Stddev kIOPS 6159.42 ( 0.00%) 3156.50 ( 48.75%) 4129.19 ( 32.96%) 3844.70 ( 37.58%) 4154.63 ( 32.55%) 7024.73 ( -14.05%) 3229.00 ( 47.58%) 3099.93 ( 49.67%) 4159.56 ( 32.47%) 4051.66 ( 34.22%) CoeffVar kIOPS 0.40 ( 0.00%) 0.21 ( 48.77%) 0.27 ( 32.94%) 0.25 ( 37.56%) 0.27 ( 32.48%) 0.46 ( -14.08%) 0.21 ( 47.60%) 0.20 ( 49.71%) 0.27 ( 32.45%) 0.26 ( 34.19%) And finally we see much more variation. I'm not sure why yet, from io_uring point of view, this should be a simple benchamrk were every operation executes inlined. My initial though is the scheduler change were we initially place new tasks. This executes independently multiple threads and agglutinates the result so perhaps we are seeing the effect of cpu in deeper sleep states getting scheduled to handle this task? Let me try that next by reverting that scheduler change. I'm also puzzled by the results of mitigations=auto, where SP5 is better than SP6. that makes no sense. Let me look into that. -- You are receiving this mail because: You are on the CC list for the bug.