Messages in this thread | | | Date | Tue, 29 Aug 2023 10:57:32 +0200 | From | Greg KH <> | Subject | Re: [PATCH v2] cpufreq: intel_pstate: set stale CPU frequency to minimum |
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On Mon, Aug 28, 2023 at 04:35:13PM -0700, Keyon Jie wrote: > > > On 8/22/23 04:46, Rafael J. Wysocki wrote: > > On Sun, Aug 20, 2023 at 10:46 PM Doug Smythies <dsmythies@telus.net> wrote: > > > > > > The intel_pstate CPU frequency scaling driver does not > > > use policy->cur and it is 0. > > > When the CPU frequency is outdated arch_freq_get_on_cpu() > > > will default to the nominal clock frequency when its call to > > > cpufreq_quick_getpolicy_cur returns the never updated 0. > > > Thus, the listed frequency might be outside of currently > > > set limits. Some users are complaining about the high > > > reported frequency, albeit stale, when their system is > > > idle and/or it is above the reduced maximum they have set. > > > > > > This patch will maintain policy_cur for the intel_pstate > > > driver at the current minimum CPU frequency. > > > > > > Reported-by: Yang Jie <yang.jie@linux.intel.com> > > > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217597 > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > > --- > > > > > > v1 -> v2: > > > * v1 was a completely different approach, programming around > > > the issue rather than fixing it at the source. > > > reference: > > > https://patchwork.kernel.org/project/linux-pm/patch/006901d9be8c$f4439930$dccacb90$@telus.net/ > > > * v2 does not fix an issue with the intel_cpufreq CPU scaling > > > driver (A.K.A. the intel_pstate driver in passive mode) and > > > the schedutil CPU frequency scaling governor when HWP is enabled > > > where limit changes are not reflected in the stale listed frequencies. > > > A fix for that will be some future patch. > > > > > > --- > > > drivers/cpufreq/intel_pstate.c | 5 +++++ > > > 1 file changed, 5 insertions(+) > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > > > index 8ca2bce4341a..08284dee583a 100644 > > > --- a/drivers/cpufreq/intel_pstate.c > > > +++ b/drivers/cpufreq/intel_pstate.c > > > @@ -2609,6 +2609,11 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy) > > > intel_pstate_clear_update_util_hook(policy->cpu); > > > intel_pstate_hwp_set(policy->cpu); > > > } > > > + /* policy current is never updated with the intel_pstate driver > > > + * but it is used as a stale frequency value. So, keep it within > > > + * limits. > > > + */ > > > + policy->cur = policy->min; > > > > > > mutex_unlock(&intel_pstate_limits_lock); > > > > > > -- > > > > Applied as 6.6 material, with some mailer-induced white space damage > > fixed and the new comment adjusted to the kernel coding style. > > > > Thanks! > > Hi Doug and Rafael, > > Thank you for making the fix happen. > > Hi Greg, > > Will this be picked to the stable linux-6.1.y and linux-6.4.y kernel, it > could benefit to users there.
Sure, when it hits Linus's tree, please follow the instructions in: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to get it merged.
thanks,
greg k-h
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