Messages in this thread | | | From | Doug Smythies <> | Date | Sun, 24 Oct 2021 15:44:03 -0700 | Subject | Re: problem in changing from active to passive mode |
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On Sun, Oct 24, 2021 at 6:03 AM Julia Lawall <julia.lawall@inria.fr> wrote: > > Hello,
Hi,
> > I have an Intel 6130 and an Intel 5218. These machines have HWP. They > are configured to boot with active mode and performance as the power > governor. Since the following commit: > > commit a365ab6b9dfbaf8fb4fb4cd5d8a4c55dc4fb8b1c (HEAD, refs/bisect/bad) > Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > Date: Mon Dec 14 21:09:26 2020 +0100 > > cpufreq: intel_pstate: Implement the ->adjust_perf() callback > > If I change te mode from active to passive, I have the impression that the > machine is no longer able to raise the core frequencies above the minimum. > Changing the mode back to active has no effect. This persists if I reboot > to another kernel. > > Here are some runs that illustrate the problem. I have tested the > benchmark many times, and apart from this issue its performance is stable.
Could you also list the CPU frequency scaling governor being used in your tests. I know you mentioned the performance governor above, but it changes between active/passive/active transitions.
Example from my test computer:
Note 1: It is only for brevity of this e-mail that I only list for one CPU. Obviously, I looked at all CPUs when doing this.
Note 2: The test example and conditions have been cherry picked for dramatic effect.
$ cat /sys/devices/system/cpu/cpu6/cpufreq/scaling_driver intel_pstate $ cat /sys/devices/system/cpu/cpu6/cpufreq/scaling_governor performance $ cat /sys/devices/system/cpu/intel_pstate/status active $ ./ping-pong-many 100000 500 10 1418.0660 usecs/loop. (less is better)
$ echo passive | sudo tee /sys/devices/system/cpu/intel_pstate/status passive $ cat /sys/devices/system/cpu/cpu6/cpufreq/scaling_driver intel_cpufreq $ cat /sys/devices/system/cpu/cpu6/cpufreq/scaling_governor schedutil $ cat /sys/devices/system/cpu/intel_pstate/status passive $ ./ping-pong-many 100000 500 10 5053.6355 usecs/loop.
$ echo active | sudo tee /sys/devices/system/cpu/intel_pstate/status active $ cat /sys/devices/system/cpu/cpu6/cpufreq/scaling_driver intel_pstate $ cat /sys/devices/system/cpu/cpu6/cpufreq/scaling_governor powersave $ cat /sys/devices/system/cpu/intel_pstate/status active $ ./ping-pong-many 100000 500 10 2253.5833 usecs/loop.
... Doug
> > Intel 6130: > > root@yeti-2:/tmp# java -jar dacapo-9.12-MR1-bach.jar avrora -n 3 > ===== DaCapo 9.12-MR1 avrora starting warmup 1 ===== > ===== DaCapo 9.12-MR1 avrora completed warmup 1 in 3420 msec ===== > ===== DaCapo 9.12-MR1 avrora starting warmup 2 ===== > ===== DaCapo 9.12-MR1 avrora completed warmup 2 in 2536 msec ===== > ===== DaCapo 9.12-MR1 avrora starting ===== > ===== DaCapo 9.12-MR1 avrora PASSED in 2502 msec ===== > root@yeti-2:/tmp# echo passive | tee /sys/devices/system/cpu/intel_pstate/status > passive > root@yeti-2:/tmp# > root@yeti-2:/tmp# echo active | tee /sys/devices/system/cpu/intel_pstate/status > active > root@yeti-2:/tmp# java -jar dacapo-9.12-MR1-bach.jar avrora -n 3 > ===== DaCapo 9.12-MR1 avrora starting warmup 1 ===== > ===== DaCapo 9.12-MR1 avrora completed warmup 1 in 7561 msec ===== > ===== DaCapo 9.12-MR1 avrora starting warmup 2 ===== > ===== DaCapo 9.12-MR1 avrora completed warmup 2 in 6528 msec ===== > ===== DaCapo 9.12-MR1 avrora starting ===== > ===== DaCapo 9.12-MR1 avrora PASSED in 7796 msec ===== > > ------------------------------------------------------------------------- > > Intel 5218: > > root@troll-2:/tmp# java -jar dacapo-9.12-MR1-bach.jar avrora -n 3 > ===== DaCapo 9.12-MR1 avrora starting warmup 1 ===== > ===== DaCapo 9.12-MR1 avrora completed warmup 1 in 2265 msec ===== > ===== DaCapo 9.12-MR1 avrora starting warmup 2 ===== > ===== DaCapo 9.12-MR1 avrora completed warmup 2 in 2033 msec ===== > ===== DaCapo 9.12-MR1 avrora starting ===== > ===== DaCapo 9.12-MR1 avrora PASSED in 2068 msec ===== > root@troll-2:/tmp# echo passive | tee /sys/devices/system/cpu/intel_pstate/status > passive > root@troll-2:/tmp# echo active | tee /sys/devices/system/cpu/intel_pstate/statusactive > root@troll-2:/tmp# java -jar dacapo-9.12-MR1-bach.jar avrora -n 3 > ===== DaCapo 9.12-MR1 avrora starting warmup 1 ===== > ===== DaCapo 9.12-MR1 avrora completed warmup 1 in 4363 msec ===== > ===== DaCapo 9.12-MR1 avrora starting warmup 2 ===== > ===== DaCapo 9.12-MR1 avrora completed warmup 2 in 4486 msec ===== > ===== DaCapo 9.12-MR1 avrora starting ===== > ===== DaCapo 9.12-MR1 avrora PASSED in 3417 msec ===== > > ------------------------------------------------------------------------- > > thanks, > julia
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