From: Dmitry Osipenko <digetx@gmail.com>
To: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Thierry Reding <thierry.reding@gmail.com>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
Kyungmin Park <kyungmin.park@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
Tomeu Vizoso <tomeu.vizoso@collabora.com>,
Peter Geis <pgwipeout@gmail.com>,
linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 17/19] PM / devfreq: tegra30: Support variable polling interval
Date: Sat, 2 Nov 2019 01:23:48 +0300 [thread overview]
Message-ID: <590f47a4-c75a-e8c9-88b8-b3cd98578969@gmail.com> (raw)
In-Reply-To: <20191101215816.GB8724@qmqm.qmqm.pl>
02.11.2019 00:58, Michał Mirosław пишет:
> On Wed, Oct 30, 2019 at 01:00:17AM +0300, Dmitry Osipenko wrote:
>> The ACTMON governor is interrupt-driven and currently hardware's polling
>> interval is fixed to 16ms in the driver. Devfreq supports variable polling
>> interval by the generic governors, let's re-use the generic interface for
>> changing of the polling interval. Now the polling interval can be changed
>> dynamically via /sys/class/devfreq/devfreq0/polling_interval.
> [...]
>> @@ -308,7 +308,7 @@ static unsigned long actmon_device_target_freq(struct tegra_devfreq *tegra,
>> unsigned int avg_sustain_coef;
>> unsigned long target_freq;
>>
>> - target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;
>> + target_freq = dev->avg_count / tegra->devfreq->profile->polling_ms;
>> avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
>> target_freq = do_percent(target_freq, avg_sustain_coef);
>> target_freq += dev->boost_freq;
>
> Noting a comment in patch 13, if this is hot path you could try reciprocal_divide().
Hello Michał,
This not really a hot path, I just wanted to optimize that case to keep
things a bit nicer.
Please take a look at the arch/arm/boot/compressed/lib1funcs.S, firstly
it checks whether divisor is a power of 2 value and then takes optimized
code path that uses a single shift. Hence the patch 13 still applies here.
next prev parent reply other threads:[~2019-11-01 22:23 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-29 22:00 [PATCH v7 00/19] More improvements for Tegra30 devfreq driver Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 01/19] PM / devfreq: tegra30: Change irq type to unsigned int Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 02/19] PM / devfreq: tegra30: Keep interrupt disabled while governor is stopped Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 03/19] PM / devfreq: tegra30: Handle possible round-rate error Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 04/19] PM / devfreq: tegra30: Drop write-barrier Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 05/19] PM / devfreq: tegra30: Fix integer overflow on CPU's freq max out Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 06/19] PM / devfreq: tegra30: Use kHz units uniformly in the code Dmitry Osipenko
2019-10-31 4:44 ` Chanwoo Choi
2019-10-31 23:08 ` Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 07/19] PM / devfreq: tegra30: Use CPUFreq notifier Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 08/19] PM / devfreq: tegra30: Move clk-notifier's registration to governor's start Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 09/19] PM / devfreq: tegra30: Reset boosting on startup Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 10/19] PM / devfreq: tegra30: Don't enable consecutive-down interrupt " Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 11/19] PM / devfreq: tegra30: Constify structs Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 12/19] PM / devfreq: tegra30: Include appropriate header Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 13/19] PM / devfreq: tegra30: Increase sampling period to 16ms Dmitry Osipenko
2019-11-01 21:53 ` Michał Mirosław
2019-10-29 22:00 ` [PATCH v7 14/19] PM / devfreq: tegra30: Don't enable already enabled consecutive interrupts Dmitry Osipenko
2019-11-01 7:00 ` Chanwoo Choi
2019-10-29 22:00 ` [PATCH v7 15/19] PM / devfreq: tegra30: Disable consecutive interrupts when appropriate Dmitry Osipenko
2019-11-01 7:01 ` Chanwoo Choi
2019-10-29 22:00 ` [PATCH v7 16/19] PM / devfreq: Add new interrupt_driven flag for governors Dmitry Osipenko
2019-11-01 7:32 ` Chanwoo Choi
2019-11-01 13:56 ` Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 17/19] PM / devfreq: tegra30: Support variable polling interval Dmitry Osipenko
2019-11-01 7:41 ` Chanwoo Choi
2019-11-01 13:55 ` Dmitry Osipenko
2019-11-01 21:58 ` Michał Mirosław
2019-11-01 22:23 ` Dmitry Osipenko [this message]
2019-11-03 15:25 ` Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 18/19] PM / devfreq: tegra30: Tune up MCCPU boost-down coefficient Dmitry Osipenko
2019-11-01 7:45 ` Chanwoo Choi
2019-11-01 14:14 ` Dmitry Osipenko
2019-10-29 22:00 ` [PATCH v7 19/19] PM / devfreq: tegra20/30: Add Dmitry as a maintainer Dmitry Osipenko
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