Re: [PATCH v1 1/2] cpufreq: ACPI: Extend frequency tables to cover boost frequencies
From: Giovanni Gherdovich <hidden>
Date: 2021-02-05 07:07:14
Also in:
linux-acpi, lkml
On Thu, 2021-02-04 at 18:25 +0100, Rafael J. Wysocki wrote:
quoted hunk ↗ jump to hunk
From: Rafael J. Wysocki <redacted> A severe performance regression on AMD EPYC processors when using the schedutil scaling governor was discovered by Phoronix.com and attributed to the following commits: 41ea667227ba ("x86, sched: Calculate frequency invariance for AMD systems") 976df7e5730e ("x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC") [snip] Fixes: 41ea667227ba ("x86, sched: Calculate frequency invariance for AMD systems") Fixes: 976df7e5730e ("x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC") Fixes: db865272d9c4 ("cpufreq: Avoid configuring old governors as default with intel_pstate") Link: https://www.phoronix.com/scan.php?page=article&item=linux511-amd-schedutil&num=1 Link: https://lore.kernel.org/linux-pm/20210203135321.12253-2-ggherdovich@suse.cz/ (local) Reported-by: Michael Larabel <redacted> Diagnosed-by: Giovanni Gherdovich [off-list ref] Signed-off-by: Rafael J. Wysocki <redacted> --- drivers/cpufreq/acpi-cpufreq.c | 107 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 95 insertions(+), 12 deletions(-) Index: linux-pm/drivers/cpufreq/acpi-cpufreq.c ===================================================================--- linux-pm.orig/drivers/cpufreq/acpi-cpufreq.c +++ linux-pm/drivers/cpufreq/acpi-cpufreq.c[...]
Tested-by: Giovanni Gherdovich <redacted> Reviewed-by: Giovanni Gherdovich <redacted> Note there is also the Tested-by: Michael, from the other thread https://lore.kernel.org/lkml/5ea06dbe-255c-3d22-b9bd-6e627c5f94af@phoronix.com/ (local) I tested this patch with the "NASA Parallel Benchmarks" from [link below], the results confirms that the 5.10 performance is recovered: Ratios of completion times, lower is better (5.10 is the baseline) 5.10 5.11-rc6 5.11-rc6-ggherdov 5.11-rc6-rafael ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Integer Sort 1.00 1.21 0.91 0.93 Embarrassingly Parallel 1.00 1.60 1.00 1.00 Discrete FFT 1.00 1.68 0.67 0.67 CPU : MODEL : 2x AMD EPYC 7742 FREQUENCY TABLE : P2: 1.50 GHz P1: 2.00 GHz P0: 2.25 GHz MAX BOOST : 3.40 GHz [link] https://www.nas.nasa.gov/publications/npb.html Thanks, Giovanni