Re: [cpufreq] 909c0e9cc1: fwq.fwq.med 210.0% improvement

From: Rong Chen
Date: Thu Mar 05 2020 - 03:18:38 EST




On 3/5/20 3:50 PM, Rafael J. Wysocki wrote:
On 3/5/2020 2:35 AM, kernel test robot wrote:
Greeting,

FYI, we noticed a 210.0% improvement of fwq.fwq.med due to commit:

Well, that sounds impressive. :-)



commit: 909c0e9cc11ba39fa5a660583b25c2431cf54deb ("cpufreq: intel_pstate: Use passive mode by default without HWP")
https://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git intel_pstate-passive

in testcase: fwq
on test machine: 16 threads Intel(R) Xeon(R) CPU D-1541 @ 2.10GHz with 48G memory
with following parameters:

    nr_task: 100%
    samples: 100000ss
    iterations: 18x
    cpufreq_governor: powersave

The governor should be schedutil, though, unless it is explicitly set to powersave in the test environment.

Is that the case?



Hi Rafael,

Yes, we set to powersave for this test.

user  :notice: [  +0.061763] 2020-03-04 21:15:33
user  :notice: [  +0.057012] for cpu_dir in /sys/devices/system/cpu/cpu[0-9]*
user  :notice: [  +0.059494] do
user  :notice: [  +0.046899]    online_file="$cpu_dir"/online
user  :notice: [  +0.074995]    [ -f "$online_file" ] && [ "$(cat "$online_file")" -eq 0 ] && continue
user  :notice: [  +0.080600] file="$cpu_dir"/cpufreq/scaling_governor
user  :notice: [  +0.067584]    [ -f "$file" ] && echo "powersave" > "$file"
user  :notice: [  +0.050203] done
user  :notice: [  +0.084039]    Internal Reference Designator: IPMI_LAN
user  :notice: [  +0.059001]    External Reference Designator: IPMI_LAN
user  :notice: [  +0.056562] IPMI Device Information
user  :notice: [  +0.058074] BMC ARP Control         : ARP Responses Enabled, Gratuitous ARP Disabled
user  :notice: [  +0.053677] 2020-03-04 21:15:34 ./t_fwq -n 100000 -w 18 -t 16
user  :notice: [Mar 4 21:22] numthreads = 16
user  :notice: [  +0.007123] thread number 1 being created.
user  :notice: [  +0.008334] thread number 2 being created.
user  :notice: [  +0.008335] thread number 3 being created.
user  :notice: [  +0.008222] thread number 4 being created.
user  :notice: [  +0.008359] thread number 5 being created.
user  :notice: [  +0.008360] thread number 6 being created.
user  :notice: [  +0.008128] thread number 7 being created.
user  :notice: [  +0.008409] thread number 8 being created.
user  :notice: [  +0.008317] thread number 9 being created.
user  :notice: [  +0.008352] thread number 10 being created.
user  :notice: [  +0.008480] thread number 11 being created.
user  :notice: [  +0.008393] thread number 12 being created.
user  :notice: [  +0.008519] thread number 13 being created.
user  :notice: [  +0.008518] thread number 14 being created.
user  :notice: [  +0.008266] thread number 15 being created.
user  :notice: [  +0.009492] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.010539] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.010499] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.010492] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.010473] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.010255] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.010525] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013377] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013653] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013755] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013936] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013843] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013884] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013685] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013835] Starting FWQ_CORE with work_length = 262144
user  :notice: [  +0.013927] Starting FWQ_CORE with work_length = 262144


Best Regards,
Rong Chen