On Tue, Aug 06, 2019 at 10:41:25PM +0800 Aaron Lu wrote: > On 2019/8/6 22:17, Phil Auld wrote: > > On Tue, Aug 06, 2019 at 09:54:01PM +0800 Aaron Lu wrote: > >> On Mon, Aug 05, 2019 at 04:09:15PM -0400, Phil Auld wrote: > >>> Hi, > >>> > >>> On Fri, Aug 02, 2019 at 11:37:15AM -0400 Julien Desfossez wrote: > >>>> We tested both Aaron's and Tim's patches and here are our results. > >>>> > >>>> Test setup: > >>>> - 2 1-thread sysbench, one running the cpu benchmark, the other one the > >>>> mem benchmark > >>>> - both started at the same time > >>>> - both are pinned on the same core (2 hardware threads) > >>>> - 10 30-seconds runs > >>>> - test script: https://paste.debian.net/plainh/834cf45c > >>>> - only showing the CPU events/sec (higher is better) > >>>> - tested 4 tag configurations: > >>>> - no tag > >>>> - sysbench mem untagged, sysbench cpu tagged > >>>> - sysbench mem tagged, sysbench cpu untagged > >>>> - both tagged with a different tag > >>>> - "Alone" is the sysbench CPU running alone on the core, no tag > >>>> - "nosmt" is both sysbench pinned on the same hardware thread, no tag > >>>> - "Tim's full patchset + sched" is an experiment with Tim's patchset > >>>> combined with Aaron's "hack patch" to get rid of the remaining deep > >>>> idle cases > >>>> - In all test cases, both tasks can run simultaneously (which was not > >>>> the case without those patches), but the standard deviation is a > >>>> pretty good indicator of the fairness/consistency. > >>>> > >>>> No tag > >>>> ------ > >>>> Test Average Stdev > >>>> Alone 1306.90 0.94 > >>>> nosmt 649.95 1.44 > >>>> Aaron's full patchset: 828.15 32.45 > >>>> Aaron's first 2 patches: 832.12 36.53 > >>>> Aaron's 3rd patch alone: 864.21 3.68 > >>>> Tim's full patchset: 852.50 4.11 > >>>> Tim's full patchset + sched: 852.59 8.25 > >>>> > >>>> Sysbench mem untagged, sysbench cpu tagged > >>>> ------------------------------------------ > >>>> Test Average Stdev > >>>> Alone 1306.90 0.94 > >>>> nosmt 649.95 1.44 > >>>> Aaron's full patchset: 586.06 1.77 > >>>> Aaron's first 2 patches: 630.08 47.30 > >>>> Aaron's 3rd patch alone: 1086.65 246.54 > >>>> Tim's full patchset: 852.50 4.11 > >>>> Tim's full patchset + sched: 390.49 15.76 > >>>> > >>>> Sysbench mem tagged, sysbench cpu untagged > >>>> ------------------------------------------ > >>>> Test Average Stdev > >>>> Alone 1306.90 0.94 > >>>> nosmt 649.95 1.44 > >>>> Aaron's full patchset: 583.77 3.52 > >>>> Aaron's first 2 patches: 513.63 63.09 > >>>> Aaron's 3rd patch alone: 1171.23 3.35 > >>>> Tim's full patchset: 564.04 58.05 > >>>> Tim's full patchset + sched: 1026.16 49.43 > >>>> > >>>> Both sysbench tagged > >>>> -------------------- > >>>> Test Average Stdev > >>>> Alone 1306.90 0.94 > >>>> nosmt 649.95 1.44 > >>>> Aaron's full patchset: 582.15 3.75 > >>>> Aaron's first 2 patches: 561.07 91.61 > >>>> Aaron's 3rd patch alone: 638.49 231.06 > >>>> Tim's full patchset: 679.43 70.07 > >>>> Tim's full patchset + sched: 664.34 210.14 > >>>> > >>> > >>> Sorry if I'm missing something obvious here but with only 2 processes > >>> of interest shouldn't one tagged and one untagged be about the same > >>> as both tagged? > >> > >> It should. > >> > >>> In both cases the 2 sysbenches should not be running on the core at > >>> the same time. > >> > >> Agree. > >> > >>> There will be times when oher non-related threads could share the core > >>> with the untagged one. Is that enough to account for this difference? > >> > >> What difference do you mean? > > > > > > I was looking at the above posted numbers. For example: > > > >>>> Sysbench mem untagged, sysbench cpu tagged > >>>> Aaron's 3rd patch alone: 1086.65 246.54 > > > >>>> Sysbench mem tagged, sysbench cpu untagged > >>>> Aaron's 3rd patch alone: 1171.23 3.35 > > > >>>> Both sysbench tagged > >>>> Aaron's 3rd patch alone: 638.49 231.06 > > > > > > Admittedly, there's some high variance on some of those numbers. > > The high variance suggests the code having some fairness issues :-) > > For the test here, I didn't expect the 3rd patch being used alone > since the fairness is solved by patch2 and patch3 together.
Makes sense, thanks. --
