linux-pm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Beata Michalska <beata.michalska@arm.com>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Prashant Malani <pmalani@google.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Jie Zhan <zhanjie9@hisilicon.com>,
	Ionela Voinescu <ionela.voinescu@arm.com>,
	Ben Segall <bsegall@google.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Ingo Molnar <mingo@redhat.com>,
	Juri Lelli <juri.lelli@redhat.com>,
	open list <linux-kernel@vger.kernel.org>,
	"open list:CPU FREQUENCY SCALING FRAMEWORK"
	<linux-pm@vger.kernel.org>, Mel Gorman <mgorman@suse.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Valentin Schneider <vschneid@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	z00813676 <zhenglifeng1@huawei.com>,
	sudeep.holla@arm.com
Subject: Re: [PATCH v2 2/2] cpufreq: CPPC: Dont read counters for idle CPUs
Date: Thu, 31 Jul 2025 22:23:24 +0200	[thread overview]
Message-ID: <aIvQvLL34br6haQi@arm.com> (raw)
In-Reply-To: <20250731111324.vv6vsh35enk3gg4h@vireshk-i7>

On Thu, Jul 31, 2025 at 04:43:24PM +0530, Viresh Kumar wrote:
> On 31-07-25, 10:27, Beata Michalska wrote:
> > I am still wondering whether cpufreq core is not a better suited place for
> > checking whether the CPU is idle. We could potentially try on anther CPU within
> > the policy and if there is none, just provide the last known freq ?
> > 
> > @Viresh: What are your thoughts on that ?
> 
> For other platforms (that' don't have counters to read), I think a call to
> ->get() to get the currently configured frequency is perfectly fine. Isn't it ?
I assume it is. I was just thinking out loud and wasn't suggesting anything
otherwise. The reason why I mentioned that is that getting current frequency
for an idle CPU seems like smth we could potentially optimise away and save some
cycles (fixing other problems on the way, like this one).
But if that's undesired for any reason, it's perfectly fine to stay with
unconditional calls to `->get()'.

---
BR
Beata
> 
> -- 
> viresh

  reply	other threads:[~2025-07-31 20:23 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-19  0:09 [PATCH v2 0/2] cpufreq: CPPC: idle cpu perf handling Prashant Malani
2025-06-19  0:09 ` [PATCH v2 1/2] sched: Expose idle_cpu() to modules Prashant Malani
2025-06-19  0:09 ` [PATCH v2 2/2] cpufreq: CPPC: Dont read counters for idle CPUs Prashant Malani
2025-06-20  3:53   ` Jie Zhan
2025-06-20  5:07     ` Prashant Malani
2025-06-26 18:42       ` Prashant Malani
2025-06-27  7:54       ` Jie Zhan
2025-06-27 17:07         ` Prashant Malani
2025-07-02 18:38           ` Prashant Malani
2025-07-03  9:29             ` Beata Michalska
2025-07-07  8:32             ` Beata Michalska
2025-07-09 17:25               ` Prashant Malani
2025-07-09 22:49                 ` Prashant Malani
2025-07-14  9:30                   ` Beata Michalska
2025-07-15  6:28                     ` Prashant Malani
2025-07-21 17:00                       ` Rafael J. Wysocki
2025-07-21 19:40                         ` Prashant Malani
2025-07-22  3:27                           ` Viresh Kumar
2025-07-22  6:02                             ` Prashant Malani
2025-07-30  7:31                               ` Prashant Malani
2025-07-31  8:27                                 ` Beata Michalska
2025-07-31 11:13                                   ` Viresh Kumar
2025-07-31 20:23                                     ` Beata Michalska [this message]
2025-08-01  4:43                                       ` Viresh Kumar
2025-08-07  0:19                                         ` Prashant Malani
2025-08-11  6:05                                           ` Viresh Kumar
2025-08-11 18:43                                             ` Prashant Malani
2025-08-11 19:19                                               ` Rafael J. Wysocki
2025-08-11 20:01                                                 ` Prashant Malani
2025-08-14 11:48                                                   ` Rafael J. Wysocki
2025-08-15  5:12                                                     ` Prashant Malani
2025-08-16  8:25                                                       ` Prashant Malani
2025-08-13 10:12                                               ` Beata Michalska
2025-07-31 16:51                                   ` Prashant Malani
2025-07-31 20:30                                     ` Beata Michalska
2025-08-01  9:16                                       ` Prashant Malani
2025-08-04 20:55                                         ` Prashant Malani
2025-08-06  7:21                                           ` Beata Michalska
2025-08-07  0:01                                             ` Prashant Malani
2025-08-07 10:24                                               ` Beata Michalska
2025-08-08  2:14                                                 ` Prashant Malani
2025-08-13 10:15                                                   ` Beata Michalska
2025-08-13 22:25                                                     ` Prashant Malani
2025-07-07  8:35         ` Beata Michalska

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=aIvQvLL34br6haQi@arm.com \
    --to=beata.michalska@arm.com \
    --cc=bsegall@google.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=ionela.voinescu@arm.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mgorman@suse.de \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=pmalani@google.com \
    --cc=rafael@kernel.org \
    --cc=rostedt@goodmis.org \
    --cc=sudeep.holla@arm.com \
    --cc=vincent.guittot@linaro.org \
    --cc=viresh.kumar@linaro.org \
    --cc=vschneid@redhat.com \
    --cc=zhanjie9@hisilicon.com \
    --cc=zhenglifeng1@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).