Messages in this thread | | | Date | Thu, 27 Jul 2023 10:56:05 +0100 | From | Will Deacon <> | Subject | Re: [PATCH] arm64: Provide an AMU-based version of arch_freq_get_on_cpu |
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On Wed, Jun 07, 2023 at 03:00:49PM +0100, Beata Michalska wrote: > On Wed, Jun 07, 2023 at 10:58:56AM +0100, Sudeep Holla wrote: > > On Tue, Jun 06, 2023 at 04:57:54PM +0100, Beata Michalska wrote: > > > With the Frequency Invariance Engine (FIE) being already wired up with > > > sched tick and making use of relevant (core counter and constant > > > counter) AMU counters, getting the current frequency for a given CPU > > > on supported platforms, can be achieved by utilizing the frequency scale > > > factor which reflects an average CPU frequency for the last tick period > > > length. > > > > > > With that at hand, arch_freq_get_on_cpu dedicated implementation > > > gets enrolled into cpuinfo_cur_freq policy sysfs attribute handler, > > > which is expected to represent the current frequency of a given CPU, > > > as obtained by the hardware. This is exactly the type of feedback that > > > cycle counters provide. > > > > > > In order to avoid calling arch_freq_get_on_cpu from the scaling_cur_freq > > > attribute handler for platforms that do provide cpuinfo_cur_freq, and > > > yet keeping things intact for those platform that do not, its use gets > > > conditioned on the presence of cpufreq_driver (*get) callback (which also > > > seems to be the case for creating cpuinfo_cur_freq attribute). > > > > > > > LGTM, > > > > Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> > > > Thanks for the review. > > However I fail to understand if both the changes are dependent ? > > Can this be split into 2 patches ? I fail to see the dependency, what > > am I missing ? Even if there is some dependency to get arch value > > (arch_freq_get_on_cpu() from show_cpuinfo_cur_freq()), you can push > > that change first followed by the arm64 change as 2 different change. > > > I guess I could split the patch into two parts: > 1. adding implementation for the arch_freq_get_on_cpu > 2. wiring it up with the cpufreq relevant attrib handlers > > or the other way round (if that's what you have in mind). > > Will wait a bit for any further comments before pushing new v.
Are you still planning on a v2?
Will
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