On 2020.07.14 11:16 Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> ... > Since the passive mode hasn't worked with HWP at all, and it is not going to > the default for HWP systems anyway, I don't see any drawbacks related to making > this change, so I would consider this as 5.9 material unless there are any > serious objections. Good point. Some of the tests I do involve labour intensive post processing of data. I want to automate some of that work, and it will take time. We might be into the 5.9-rc series before I have detailed feedback. However, so far: Inverse impulse response test [1]: High level test, i5-9600K, HWP-passive (this patch), ondemand: 3101 tests. 0 failures. (GOOD) >From [1], re-stated: > . High level: i5-9600K: 2453 tests, 60 failures, 2.45% fail rate. (HWP-active - powersave) > . Verify acpi-cpufreq/ondemand works fine: i5-9600K: 8975 tests. 0 failures. My version of that cool Alexander named pipe test [2] serialized workflow: HWP-passive (this patch), performance: PASS. >From [2], re-stated, and also re-tested. HWP-disabled passive - performance: FAIL. Although, I believe the issue to be EPB management, [3]. And yes, I did see the reply to [3] that came earlier, And have now re-done the test, with the referenced patch added. It still is FAIL. I reply to the [3] thread, eventually. [1] https://marc.info/?l=linux-pm&m=159354421400342&w=2 [2] https://marc.info/?l=linux-pm&m=159155067328641&w=2 [3] https://marc.info/?l=linux-pm&m=159438804230744&w=2 Kernel: b08284a541ad (HEAD -> k58rc5-doug) cpufreq: intel_pstate: Avoid enabling HWP if EPP is not supported 063fd7ccabfe cpufreq: intel_pstate: Implement passive mode with HWP enabled 730ccf5054e9 cpufreq: intel_pstate: Allow raw energy performance preference value bee36df01c68 cpufreq: intel_pstate: Allow enable/disable energy efficiency 199629d8200e cpufreq: intel_pstate: Fix active mode setting from command line 11ba468877bb (tag: v5.8-rc5, origin/master, origin/HEAD, master) Linux 5.8-rc5 Rules for this work: . never use x86_energy_perf_policy. . For HWP disabled: never change from active to passive or via versa, but rather do it via boot. . after boot always check and reset the various power limit log bits that are set. . never compile the kernel (well, until after any tests), which will set those bits again. . never run prime95 high heat torture test, which will set those bits again. . try to never do anything else that will set those bits again. To be clear, I do allow changing governors within the context of the above rules. ... Doug
