From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Doug Smythies <dsmythies@telus.net>,
Giovanni Gherdovich <ggherdovich@suse.com>
Subject: [PATCH v2 0/3] cpufreq: Allow drivers to receive more information from the governor
Date: Mon, 14 Dec 2020 21:01:52 +0100 [thread overview]
Message-ID: <3827230.0GnL3RTcl1@kreacher> (raw)
In-Reply-To: <20360841.iInq7taT2Z@kreacher>
Hi,
The timing of this is not perfect (sorry about that), but here's a refresh
of this series.
The majority of the previous cover letter still applies:
On Monday, December 7, 2020 5:25:38 PM CET Rafael J. Wysocki wrote:
>
> This is based on the RFC posted a few days ago:
>
> https://lore.kernel.org/linux-pm/1817571.2o5Kk4Ohv2@kreacher/
>
> Using intel_pstate in the passive mode with HWP enabled, in particular under
> the schedutil governor, is still kind of problematic, because it has to assume
> that it should not allow the frequency to fall below the one requested by the
> governor. For this reason, it translates the target frequency into HWP.REQ.MIN
> which generally causes the processor to run a bit too fast.
>
> Moreover, this allows the HWP algorithm to use any frequency between the target
> one and HWP.REQ.MAX that corresponds to the policy max limit and some workloads
> cause it to go for the max turbo frequency prematurely which hurts energy-
> efficiency without improving performance, even though the schedutil governor
> itself would not allow the frequency to ramp up so fast.
>
> This patch series attempts to improve the situation by introducing a new driver
> callback allowing the driver to receive more information from the governor. In
> particular, this allows the min (required) and target (desired) performance
> levels to be passed to it and those can be used to give better hints to the
> hardware.
In this second revision there are three patches (one preparatory patch for
schedutil that hasn't changed since the v1, the introduction of the new
callback and schedutil changes in patch [2/3] and the intel_pstate changes
in patch [3/3] that are the same as before.
Please see patch changelogs for details.
Thanks!
next prev parent reply other threads:[~2020-12-14 20:11 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 16:25 [PATCH v1 0/4] cpufreq: Allow drivers to receive more information from the governor Rafael J. Wysocki
2020-12-07 16:28 ` [PATCH v1 1/4] cpufreq: schedutil: Add util to struct sg_cpu Rafael J. Wysocki
2020-12-08 8:33 ` Viresh Kumar
2020-12-09 17:17 ` Rafael J. Wysocki
2020-12-07 16:29 ` [PATCH v1 2/4] cpufreq: schedutil: Adjust utilization instead of frequency Rafael J. Wysocki
2020-12-08 8:51 ` Viresh Kumar
2020-12-08 17:01 ` Rafael J. Wysocki
2020-12-09 5:16 ` Viresh Kumar
2020-12-09 15:32 ` Rafael J. Wysocki
2020-12-14 11:07 ` Viresh Kumar
2020-12-07 16:35 ` [PATCH v1 3/4] cpufreq: Add special-purpose fast-switching callback for drivers Rafael J. Wysocki
2020-12-08 9:02 ` Viresh Kumar
2020-12-15 4:16 ` Viresh Kumar
2020-12-15 15:38 ` Rafael J. Wysocki
2020-12-07 16:38 ` [PATCH v1 4/4] cpufreq: intel_pstate: Implement the ->adjust_perf() callback Rafael J. Wysocki
2020-12-08 12:43 ` Peter Zijlstra
2020-12-08 17:10 ` Rafael J. Wysocki
2020-12-08 16:30 ` [PATCH v1 0/4] cpufreq: Allow drivers to receive more information from the governor Giovanni Gherdovich
2020-12-08 17:13 ` Rafael J. Wysocki
2020-12-08 19:14 ` Doug Smythies
2020-12-13 19:12 ` Doug Smythies
2020-12-18 15:32 ` Peter Zijlstra
2020-12-14 20:01 ` Rafael J. Wysocki [this message]
2020-12-14 20:04 ` [PATCH v2 1/3] cpufreq: schedutil: Add util to struct sg_cpu Rafael J. Wysocki
2020-12-14 20:08 ` [PATCH v2 2/3] cpufreq: Add special-purpose fast-switching callback for drivers Rafael J. Wysocki
2020-12-14 20:09 ` [PATCH v2 3/3] cpufreq: intel_pstate: Implement the ->adjust_perf() callback Rafael J. Wysocki
2020-12-15 3:29 ` Srinivas Pandruvada
2020-12-15 4:16 ` [PATCH v2 0/3] cpufreq: Allow drivers to receive more information from the governor Viresh Kumar
2020-12-17 15:26 ` Doug Smythies
2020-12-21 10:41 ` Rafael J. Wysocki
2020-12-18 16:11 ` Giovanni Gherdovich
2020-12-21 16:11 ` Rafael J. Wysocki
2020-12-23 13:06 ` Giovanni Gherdovich
2020-12-28 19:11 ` Rafael J. Wysocki
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