http://bugzilla.suse.com/show_bug.cgi?id=1131437 http://bugzilla.suse.com/show_bug.cgi?id=1131437#c6 Mel Gorman <mgorman@suse.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mgorman@suse.com --- Comment #6 from Mel Gorman <mgorman@suse.com> --- (In reply to Jan Kara from comment #5)
OK, when the machine is booted with intel_idle.max_cstate=1, the numbers are much more stable (did run just for 1, 2, and 4 clients):
Amean 1 36.13 ( 0.00%) 35.76 ( 1.03%) 36.18 ( -0.14% ) 36.44 ( -0.86%) 36.43 ( -0.82%) Amean 2 34.63 ( 0.00%) 31.68 ( 8.50%) 31.83 ( 8.08% ) 31.59 ( 8.77%) 31.70 ( 8.45%) Amean 4 40.73 ( 0.00%) 38.24 ( 6.13%) 39.73 ( 2.46% ) 40.53 ( 0.51%) 40.29 ( 1.09%) Stddev 1 4.65 ( 0.00%) 4.17 ( 10.35%) 4.44 ( 4.43% ) 3.59 ( 22.76%) 4.39 ( 5.45%) Stddev 2 6.42 ( 0.00%) 6.18 ( 3.81%) 6.16 ( 4.09%) 6.38 ( 0.58%) 6.10 ( 4.97%) Stddev 4 5.94 ( 0.00%) 5.57 ( 6.11%) 5.89 ( 0.80%) 5.76 ( 2.97%) 5.64 ( 4.97%)
I'm going to verify now how stock 4.20 dbench numbers are / aren't stable to see whether this instability is a recent thing.
If 4.20 looks good, I would suggest taking a close look / revert of 8e3b40395450 ("cpufreq: intel_pstate: Fix up iowait_boost computation") and the base commit it relies on b8bd1581aa61 ("cpufreq: intel_pstate: Rework iowait boosting to be less aggressive") because they have "potential to regress workloads that pause on IO for short periods" written all over them. -- You are receiving this mail because: You are on the CC list for the bug.