Re: [dpdk-dev] [PATCH v1 1/1] test/power: check cpuinfo cur freq before scaling cur freq

[Richael Zhuang <Richael.Zhuang@arm.com>]

> -----Original Message-----
> From: David Hunt <david.hunt@intel.com>
> Sent: Wednesday, July 14, 2021 6:14 PM
> To: Richael Zhuang <Richael.Zhuang@arm.com>; dev@dpdk.org
> Cc: zhiminx.huang@intel.com; stable@dpdk.org; nd <nd@arm.com>
> Subject: Re: [PATCH v1 1/1] test/power: check cpuinfo cur freq before scaling
> cur freq
> 
> 
> On 14/7/2021 10:23 AM, Richael Zhuang wrote:
> >
> >> -----Original Message-----
> >> From: David Hunt <david.hunt@intel.com>
> >> Sent: Wednesday, July 14, 2021 5:15 PM
> >> To: Richael Zhuang <Richael.Zhuang@arm.com>; dev@dpdk.org
> >> Cc: zhiminx.huang@intel.com; stable@dpdk.org
> >> Subject: Re: [PATCH v1 1/1] test/power: check cpuinfo cur freq before
> >> scaling cur freq
> >>
> >>
> >> On 14/7/2021 9:44 AM, Richael Zhuang wrote:
> >>> For acpi_cpufreq and cppc_cpufreq, both cpuinfo_cur_freq and
> >>> scaling_cur_freq exist. For pstate, only scaling_cur_freq exists.
> >>> And value in scaling_cur_freq and cpuinfo_cur_freq may not be the
> >>> same. For acpi_cpufreq and cppc_cpufreq, we should check
> >>> cpuinfo_cur_freq. So here checking cpuinfo_cur_freq before
> >>> scaling_cur_freq to make sure it works for all cpufreq drivers.
> >>>
> >>> Fixes: ff6dfb8e492f ("test/power: fix CPU frequency check")
> >>> Cc: david.hunt@intel.com
> >>> Cc: stable@dpdk.org
> >>>
> >>> Signed-off-by: Richael Zhuang <richael.zhuang@arm.com>
> >>> ---
> >>>    app/test/test_power_cpufreq.c | 4 ++--
> >>>    1 file changed, 2 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/app/test/test_power_cpufreq.c
> >>> b/app/test/test_power_cpufreq.c index b8fc53925c..f56abb6f86 100644
> >>> --- a/app/test/test_power_cpufreq.c
> >>> +++ b/app/test/test_power_cpufreq.c
> >>> @@ -62,13 +62,13 @@ check_cur_freq(unsigned int lcore_id, uint32_t
> >>> idx,
> >> bool turbo)
> >>>    	int i;
> >>>
> >>>    	if (snprintf(fullpath, sizeof(fullpath),
> >>> -		TEST_POWER_SYSFILE_SCALING_FREQ, lcore_id) < 0) {
> >>> +		TEST_POWER_SYSFILE_CPUINFO_FREQ, lcore_id) < 0) {
> >>>    		return 0;
> >>>    	}
> >>>    	f = fopen(fullpath, "r");
> >>>    	if (f == NULL) {
> >>>    		if (snprintf(fullpath, sizeof(fullpath),
> >>> -			TEST_POWER_SYSFILE_CPUINFO_FREQ, lcore_id) < 0)
> >> {
> >>> +			TEST_POWER_SYSFILE_SCALING_FREQ, lcore_id) < 0)
> >> {
> >>>    			return 0;
> >>>    		}
> >>>    		f = fopen(fullpath, "r");
> >>
> >> Hi Richael, I don't think this patch fixes anything. If the scaling
> >> file is not available, it will then attempt to open the cpuinfo file.
> >> Changing the order does not address the underlying issue.
> >>
> >> It looks like the test is failing in check_cur_req, which is only
> >> rounding for cppc driver. I think it also needs to round for the
> >> other drivers. I've just checked intel_pstate driver now, and it
> >> needs the rounding. I would think that acpi driver also needs it.
> >> I'll do a bit more investigation and see if I can  change to acpi and attempt
> to confirm that all drivers need the rounding.
> >>
> >> Rgds,
> >> Dave.
> >>
> >>
> > Hi David,
> > For acpi_cpufreq and cppc_cpufreq, both two files exist. So with the
> current code, it will check the scaling_cur_freq. But I think for this two drivers,
> it should check cpuinfo_cur_freq but not scaling_cur_freq. From my system,
> for acpi cpufreq, the value in cpuinfo_cur_freq and scaling_cur_freq are not
> the same.
> 
> 
> Ah OK. Now I see different the values in scaling_cur_freq and
> cpuinfo_cur_freq on a system here with acpi driver. The cpuinfo_cur_freq is
> already rounded, but the scaling_cur_freq is not.
> 
> # cat /sys/devices/system/cpu/cpu2/cpufreq/scaling_cur_freq
> 800259
> # cat /sys/devices/system/cpu/cpu2/cpufreq/cpuinfo_cur_freq
> 800000
> 
> So I think it would make sense to include the re-order of the filenames as you
> suggest, but maybe also add rounding for the pstate driver, as that is needed.
> 
> -               if (env == PM_ENV_CPPC_CPUFREQ) {
> +               if ((env == PM_ENV_CPPC_CPUFREQ) || (env ==
> PM_ENV_PSTATE_CPUFREQ)) {
> 
> That avoids the complication of the acpi_cpufreq driver when turbo is
> enabled (2301000 for any turbo freq).
> 
> I've just run the test with the two changes (reorder filenames and round
> on pstate), and the power_cpufreq_autotest passes on both intel_pstate
> and acpi-cpufreq driver systems.
> 
> Regards,
> Dave.
> 
> 
Hi David,
For I don't have a platform with pstate available now,  I can’t  verify it by myself. Thanks for your test and conclusion, I will include" env ==
 PM_ENV_PSTATE_CPUFREQ".

> 
> >    So if not changing the check sequence, the result is:
> > ##########
> > RTE>>power_cpufreq_autotest
> > POWER: Env isn't set yet!
> > POWER: Attempting to initialise ACPI cpufreq power management...
> > POWER: Initialized successfully for lcore 2 power management
> > POWER: Power management of lcore 2 has exited from 'userspace' mode
> and been set back to the original
> > POWER: Lcore id 128 can not exceeds 127
> > POWER: Initialized successfully for lcore 2 power management
> > POWER: Power management of lcore 2 is in use
> > POWER: Invalid lcore ID
> > POWER: NULL buffer supplied
> > POWER: Buffer size is not enough
> > POWER: Invalid lcore ID
> > POWER: Power management of lcore 2 has exited from 'userspace' mode
> and been set back to the original
> > Test Failed
> > RTE>>quit
> > #############
> >
> > But after changing the check sequence, the result is OK from my test:
> > ######
> > RTE>>power_cpufreq_autotest
> > POWER: Env isn't set yet!
> > POWER: Attempting to initialise ACPI cpufreq power management...
> > POWER: Initialized successfully for lcore 2 power management
> > POWER: Power management of lcore 2 has exited from 'userspace' mode
> and been set back to the original
> > POWER: Lcore id 128 can not exceeds 127
> > POWER: Initialized successfully for lcore 2 power management
> > POWER: Power management of lcore 2 is in use
> > POWER: Invalid lcore ID
> > POWER: NULL buffer supplied
> > POWER: Buffer size is not enough
> > POWER: Invalid lcore ID
> > POWER: Invalid lcore ID
> > POWER: Invalid frequency index 64, which should be less than 3
> > POWER: Invalid frequency index 3, which should be less than 3
> > POWER: Failed to enable turbo on lcore 2
> > POWER: Invalid lcore ID
> > POWER: Invalid lcore ID
> > POWER: Invalid lcore ID
> > POWER: Invalid lcore ID
> > Turbo not available on lcore 2, skipping test
> > POWER: Power management of lcore 2 has exited from 'userspace' mode
> and been set back to the original
> > POWER: Power management of lcore 2 is not used
> > POWER: Lcore id 128 can not exceeds 127
> > Test OK
> > ############