| Message ID | 20210122204038.3238-1-ggherdovich@suse.cz |
|---|---|
| Headers | show |
| Series | AMD EPYC: fix schedutil perf regression (freq-invariance) | expand |
From ongoing tests of this patch, it still certainly shows to address most of the Linux 5.11 performance regression previously encountered when using Schedutil. Additionally, for a number of workloads where not seeing a regression from 5.10 to 5.11 Git is still showing even better performance with this patch. The power monitoring on the AMD EPYC server is showing higher power spikes but the average power consumption rate is roughly comparable to that of Linux 5.11 Git, which is higher than 5.10 by just about 3%. So this patch still seems to be working out well and indeed taking care of some wide losses seen otherwise on Linux 5.11 when using Schedutil on AMD Zen2/Zen3. Still have some other tests running but so far no unexpected results. Michael AMD EPYC 7F72 2P On an EPYC 7F72 2P server[1] across 147 test cases I am finding the patched Linux 5.11 kernel to be just over 1% faster than 5.10 stable compared to the unpatched 5.11 Git being just behind 5.10. For the workloads on that server where Linux 5.11 is slower with Schedutil, the patch indeed is largely addressing that regression and also providing other improvements. During that testing, the amd_energy interface was monitored. Linux 5.11 with Schedutil AMD freq invariance did show on average 10 Watts (~3.7%) higher power consumption on average than Linux 5.10 with Schedutil. But with this patch, that average is still basically the same. The peak power consumption during any of the tests was higher at 530~549 Watts compared to 501 Watts with Linux 5.10. Overall the performance is looking good but given amd_energy still not working for consumer models, I don't have much power data to share at the moment. Ryzen 9 5950X Expanding on the prior testing with the 5950X, I ran some follow-up tests[2]. Of 221 test cases there, the current Linux 5.11 Git performance came around 2% slower on a geo mean basis than Linux 5.10 while the patched performance pulls it to ~2.5% faster than 5.10. There still are some cases where Linux 5.10 is faster, but overall at least the patched Linux 5.11 performance doesn't show nearly as many regressions. In a number of test cases, the Linux 5.11 patched performance is outright better than Linux 5.10 even where 5.11 (un-patched) hadn't regressed or by that much. Ryzen 5 4500U For something at the lower end of the spectrum I also ran a number of tests on a Ryzen 5 4500U notebook[3]. Linux 5.11 (unpatched) doesn't see as many regressions as on the larger systems but still the patched performance did help in a number of tests, particularly around graphics/gaming. In the heavier multi-core core tests are still a number of cases where Linux 5.10 is faster than patched/unpatched 5.11. The patched kernel in those 90 tests came out to being about 4% faster than 5.10. (Result highlights below, results with little change set to hidden by default.) [1] https://openbenchmarking.org/result/2101248-HA-AMDEPYC7F52&grs&hlc=1&hnr=1&hlc=1 [2] https://openbenchmarking.org/result/2101242-HA-RYZEN959530&grs&hlc=1 [3] https://openbenchmarking.org/result/2101232-PTS-RENOIRLI89&grs&hnr=1&hlc=1 On 1/22/21 2:40 PM, Giovanni Gherdovich wrote: > Michael Larabel from Phoronix.com graciously tested v1, see results at: > > AMD EPYC 7702 - > https://openbenchmarking.org/result/2101210-PTS-LINUX51178 > > AMD Ryzen 9 5950X - > https://openbenchmarking.org/result/2101212-HA-RYZEN959566 > > The reported regression is recovered, and some workloads even report an > improvement over the v5.10 results. > > Thanks Michael for the feedback! > > > v1 at https://lore.kernel.org/lkml/20210121003223.20257-1-ggherdovich@suse.cz/ > > Changes wrt v1: > > - move code around so that it builds for non-x86 architectures too > > Giovanni Gherdovich (1): > x86,sched: On AMD EPYC set freq_max = max_boost in schedutil invariant > formula > > drivers/cpufreq/acpi-cpufreq.c | 64 +++++++++++++++++++++++++++++++- > drivers/cpufreq/cpufreq.c | 3 ++ > include/linux/cpufreq.h | 5 +++ > kernel/sched/cpufreq_schedutil.c | 8 +++- > 4 files changed, 76 insertions(+), 4 deletions(-) >
On Sun, Jan 24, 2021 at 04:30:57PM -0600, Michael Larabel wrote: > From ongoing tests of this patch, it still certainly shows to address most > of the Linux 5.11 performance regression previously encountered when using > Schedutil. Additionally, for a number of workloads where not seeing a > regression from 5.10 to 5.11 Git is still showing even better performance > with this patch. The power monitoring on the AMD EPYC server is showing > higher power spikes but the average power consumption rate is roughly > comparable to that of Linux 5.11 Git, which is higher than 5.10 by just > about 3%. > > So this patch still seems to be working out well and indeed taking care of > some wide losses seen otherwise on Linux 5.11 when using Schedutil on AMD > Zen2/Zen3. Still have some other tests running but so far no unexpected > results. > Did you do all this writing and forget to add: Tested-by: Michael Larabel <Michael@phoronix.com> ?
On Mon, 2021-01-25 at 09:34 +0100, Peter Zijlstra wrote: > On Sun, Jan 24, 2021 at 04:30:57PM -0600, Michael Larabel wrote: > > From ongoing tests of this patch, it still certainly shows to address most > > of the Linux 5.11 performance regression previously encountered when using > > Schedutil. Additionally, for a number of workloads where not seeing a > > regression from 5.10 to 5.11 Git is still showing even better performance > > with this patch. The power monitoring on the AMD EPYC server is showing > > higher power spikes but the average power consumption rate is roughly > > comparable to that of Linux 5.11 Git, which is higher than 5.10 by just > > about 3%. > > > > So this patch still seems to be working out well and indeed taking care of > > some wide losses seen otherwise on Linux 5.11 when using Schedutil on AMD > > Zen2/Zen3. Still have some other tests running but so far no unexpected > > results. > > > > Did you do all this writing and forget to add: > > Tested-by: Michael Larabel <Michael@phoronix.com> > > ? Michael confirmed me off-list that yes, the patch should carry the "Tested-by" tag with his name. Giovanni
Michael Larabel from Phoronix.com graciously tested v1, see results at: AMD EPYC 7702 - https://openbenchmarking.org/result/2101210-PTS-LINUX51178 AMD Ryzen 9 5950X - https://openbenchmarking.org/result/2101212-HA-RYZEN959566 The reported regression is recovered, and some workloads even report an improvement over the v5.10 results. Thanks Michael for the feedback! v1 at https://lore.kernel.org/lkml/20210121003223.20257-1-ggherdovich@suse.cz/ Changes wrt v1: - move code around so that it builds for non-x86 architectures too Giovanni Gherdovich (1): x86,sched: On AMD EPYC set freq_max = max_boost in schedutil invariant formula drivers/cpufreq/acpi-cpufreq.c | 64 +++++++++++++++++++++++++++++++- drivers/cpufreq/cpufreq.c | 3 ++ include/linux/cpufreq.h | 5 +++ kernel/sched/cpufreq_schedutil.c | 8 +++- 4 files changed, 76 insertions(+), 4 deletions(-)