Messages in this thread | | | Date | Fri, 15 May 2020 09:43:39 +0800 | From | Oliver Sang <> | Subject | Re: [sched/fair] 0b0695f2b3: phoronix-test-suite.compress-gzip.0.seconds 19.8% regression |
| |
On Thu, May 14, 2020 at 07:09:35PM +0200, Vincent Guittot wrote: > Hi Oliver, > > On Thu, 14 May 2020 at 16:05, kernel test robot <oliver.sang@intel.com> wrote: > > > > Hi Vincent Guittot, > > > > Below report FYI. > > Last year, we actually reported an improvement "[sched/fair] 0b0695f2b3: > > vm-scalability.median 3.1% improvement" on link [1]. > > but now we found the regression on pts.compress-gzip. > > This seems align with what showed in "[v4,00/10] sched/fair: rework the CFS > > load balance" (link [2]), where showed the reworked load balance could have > > both positive and negative effect for different test suites. > > We have tried to run all possible use cases but it's impossible to > covers all so there were a possibility that one that is not covered, > would regressed. > > > And also from link [3], the patch set risks regressions. > > > > We also confirmed this regression on another platform > > (Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz with 8G memory), > > below is the data (lower is better). > > v5.4 4.1 > > fcf0553db6f4c79387864f6e4ab4a891601f395e 4.01 > > 0b0695f2b34a4afa3f6e9aa1ff0e5336d8dad912 4.89 > > v5.5 5.18 > > v5.6 4.62 > > v5.7-rc2 4.53 > > v5.7-rc3 4.59 > > > > It seems there are some recovery on latest kernels, but not fully back. > > We were just wondering whether you could share some lights the further works > > on the load balance after patch set [2] which could cause the performance > > change? > > And whether you have plan to refine the load balance algorithm further? > > I'm going to have a look at your regression to understand what is > going wrong and how it can be fixed
Thanks a lot!
> > Thanks > Vincent >
| |