Linux-PM Archive on lore.kernel.org
 help / color / Atom feed
From: Chanwoo Choi <cw00.choi@samsung.com>
To: Dmitry Osipenko <digetx@gmail.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	MyungJoo Ham <myungjoo.ham@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 18/24] PM / devfreq: tegra30: Optimize CPUFreq notifier
Date: Thu, 18 Jul 2019 18:48:42 +0900
Message-ID: <ce18694a-4281-a245-7bdf-299fedc3c724@samsung.com> (raw)
In-Reply-To: <20190707223303.6755-19-digetx@gmail.com>

On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote:
> When CPU's memory activity is low or memory activity is high such that
> CPU's frequency contribution to the boosting is not taken into account,
> then there is no need to schedule devfreq's update. This eliminates
> unnecessary CPU activity during of idling caused by the scheduled work.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/devfreq/tegra30-devfreq.c | 73 +++++++++++++++++++++++++++----
>  1 file changed, 64 insertions(+), 9 deletions(-)

Patch4 add the 'cpufreq notifier' and this patch optimize the cpufreq notifier.
I think t hat you can combine two patches.

> 
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index 43c9c5fbfe91..8d6bf6e9f1ae 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -216,10 +216,10 @@ static inline unsigned long do_percent(unsigned long val, unsigned int pct)
>  	return val * pct / 100;
>  }
>  
> -static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra)
> +static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,
> +					    unsigned int cpu_freq)
>  {
>  	const struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios;
> -	unsigned int cpu_freq = cpufreq_get(0);
>  	unsigned int i;
>  
>  	for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) {
> @@ -239,15 +239,15 @@ tegra_actmon_account_cpu_freq(struct tegra_devfreq *tegra,
>  			      struct tegra_devfreq_device *dev,
>  			      unsigned long target_freq)
>  {
> -	unsigned long static_cpu_emc_freq;
> +	unsigned long cpu_emc_freq = 0;
>  
> -	if (dev->config->avg_dependency_threshold &&
> -	    dev->config->avg_dependency_threshold < dev->avg_freq) {
> -		static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra);
> -		target_freq = max(target_freq, static_cpu_emc_freq);
> -	}
> +	if (!dev->config->avg_dependency_threshold)
> +		return target_freq;
>  
> -	return target_freq;
> +	if (dev->avg_freq > dev->config->avg_dependency_threshold)
> +		cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpufreq_get(0));
> +
> +	return max(target_freq, cpu_emc_freq);
>  }
>  
>  static unsigned long tegra_actmon_lower_freq(struct tegra_devfreq *tegra,
> @@ -531,16 +531,71 @@ static void tegra_actmon_delayed_update(struct work_struct *work)
>  	mutex_unlock(&tegra->devfreq->lock);
>  }
>  
> +static unsigned long
> +tegra_actmon_cpufreq_contribution(struct tegra_devfreq *tegra,
> +				  unsigned int cpu_freq)
> +{
> +	unsigned long freq, static_cpu_emc_freq;
> +
> +	/* check whether CPU's freq is taken into account at all */
> +	if (tegra->devices[MCCPU].avg_freq <=
> +	    tegra->devices[MCCPU].config->avg_dependency_threshold)
> +		return 0;
> +
> +	static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
> +
> +	/* compare static CPU-EMC freq with MCALL */
> +	freq = tegra->devices[MCALL].avg_freq +
> +	       tegra->devices[MCALL].boost_freq;
> +
> +	freq = tegra_actmon_upper_freq(tegra, freq);
> +
> +	if (freq == tegra->max_freq || freq >= static_cpu_emc_freq)
> +		return 0;
> +
> +	/* compare static CPU-EMC freq with MCCPU */
> +	freq = tegra->devices[MCCPU].avg_freq +
> +	       tegra->devices[MCCPU].boost_freq;
> +
> +	freq = tegra_actmon_upper_freq(tegra, freq);
> +
> +	if (freq == tegra->max_freq || freq >= static_cpu_emc_freq)
> +		return 0;
> +
> +	return static_cpu_emc_freq;
> +}
> +
>  static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb,
>  				      unsigned long action, void *ptr)
>  {
> +	struct cpufreq_freqs *freqs = ptr;
>  	struct tegra_devfreq *tegra;
> +	unsigned long old, new;
>  
>  	if (action != CPUFREQ_POSTCHANGE)
>  		return NOTIFY_OK;
>  
>  	tegra = container_of(nb, struct tegra_devfreq, cpu_rate_change_nb);
>  
> +	/*
> +	 * Quickly check whether CPU frequency should be taken into account
> +	 * at all, without blocking CPUFreq's core.
> +	 */
> +	if (mutex_trylock(&tegra->devfreq->lock)) {
> +		old = tegra_actmon_cpufreq_contribution(tegra, freqs->old);
> +		new = tegra_actmon_cpufreq_contribution(tegra, freqs->new);
> +		mutex_unlock(&tegra->devfreq->lock);
> +
> +		/*
> +		 * If CPU's frequency shouldn't be taken into account at
> +		 * the moment, then there is no need to update the devfreq's
> +		 * state because ISR will re-check CPU's frequency on the
> +		 * next interrupt.
> +		 */
> +		if (old == new)
> +			return NOTIFY_OK;
> +	}
> +
>  	/*
>  	 * CPUFreq driver should support CPUFREQ_ASYNC_NOTIFICATION in order
>  	 * to allow asynchronous notifications. This means we can't block
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

  reply index

Thread overview: 94+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-07 22:32 [PATCH v4 00/24] More improvements for Tegra30 devfreq driver Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 01/24] PM / devfreq: tegra30: Change irq type to unsigned int Dmitry Osipenko
2019-07-16 11:35   ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 02/24] PM / devfreq: tegra30: Keep interrupt disabled while governor is stopped Dmitry Osipenko
2019-07-16 11:47   ` Chanwoo Choi
2019-07-16 13:03     ` Dmitry Osipenko
2019-07-17  6:37       ` Chanwoo Choi
2019-07-17 16:44         ` Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 03/24] PM / devfreq: tegra30: Handle possible round-rate error Dmitry Osipenko
2019-07-16 11:50   ` Chanwoo Choi
2019-07-16 13:09     ` Dmitry Osipenko
2019-07-17  6:38       ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 04/24] PM / devfreq: tegra30: Drop write-barrier Dmitry Osipenko
2019-07-16 11:51   ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 05/24] PM / devfreq: tegra30: Set up watermarks properly Dmitry Osipenko
2019-07-18 10:17   ` Chanwoo Choi
2019-07-19  0:00     ` Dmitry Osipenko
2019-07-19  1:31       ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 06/24] PM / devfreq: tegra30: Tune up boosting thresholds Dmitry Osipenko
2019-07-16 11:55   ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 07/24] PM / devfreq: tegra30: Use CPUFreq notifier Dmitry Osipenko
2019-07-16 12:08   ` Chanwoo Choi
2019-07-16 13:18     ` Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 08/24] PM / devfreq: tegra30: Move clk-notifier's registration to governor's start Dmitry Osipenko
2019-07-16 12:11   ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 09/24] PM / devfreq: tegra30: Reset boosting on startup Dmitry Osipenko
2019-07-16 12:13   ` Chanwoo Choi
2019-07-16 13:19     ` Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 10/24] PM / devfreq: tegra30: Don't enable consecutive-down interrupt " Dmitry Osipenko
2019-07-16 12:17   ` Chanwoo Choi
2019-07-16 15:17     ` Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 11/24] PM / devfreq: tegra30: Add debug messages Dmitry Osipenko
2019-07-16 12:23   ` Chanwoo Choi
2019-07-16 13:26     ` Dmitry Osipenko
2019-07-17  6:45       ` Chanwoo Choi
2019-07-17 15:46         ` Dmitry Osipenko
2019-07-18  9:07           ` Chanwoo Choi
2019-07-19  1:13             ` Dmitry Osipenko
2019-07-19  1:22               ` Chanwoo Choi
2019-07-19 17:10                 ` Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 12/24] PM / devfreq: tegra30: Inline all one-line functions Dmitry Osipenko
2019-07-16 12:26   ` Chanwoo Choi
2019-07-16 13:35     ` Dmitry Osipenko
2019-07-18  9:09       ` Chanwoo Choi
2019-07-19  1:22         ` Dmitry Osipenko
2019-07-19  1:24           ` Chanwoo Choi
2019-07-19  1:27             ` Chanwoo Choi
2019-07-19  2:14               ` Dmitry Osipenko
2019-07-19  6:01                 ` Chanwoo Choi
2019-07-19 16:52                   ` Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 13/24] PM / devfreq: tegra30: Constify structs Dmitry Osipenko
2019-07-16 12:26   ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 14/24] PM / devfreq: tegra30: Ensure that target freq won't overflow Dmitry Osipenko
2019-07-16 12:30   ` Chanwoo Choi
2019-07-16 13:59     ` Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 15/24] PM / devfreq: tegra30: Fix integer overflow on CPU's freq max out Dmitry Osipenko
2019-07-16 12:32   ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 16/24] PM / devfreq: tegra30: Use kHz units uniformly in the code Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 17/24] PM / devfreq: tegra30: Use tracepoints for debugging Dmitry Osipenko
2019-07-18  9:47   ` Chanwoo Choi
2019-07-19  0:49     ` Dmitry Osipenko
2019-07-19  1:01       ` Chanwoo Choi
2019-07-19  1:50         ` Dmitry Osipenko
2019-07-07 22:32 ` [PATCH v4 18/24] PM / devfreq: tegra30: Optimize CPUFreq notifier Dmitry Osipenko
2019-07-18  9:48   ` Chanwoo Choi [this message]
2019-07-19  0:42     ` Dmitry Osipenko
2019-07-19  1:09       ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 19/24] PM / devfreq: tegra30: Optimize upper consecutive watermark selection Dmitry Osipenko
2019-07-18  9:51   ` Chanwoo Choi
2019-07-19  0:40     ` Dmitry Osipenko
2019-07-19  1:15       ` Chanwoo Choi
2019-07-19  1:17         ` Chanwoo Choi
2019-07-07 22:32 ` [PATCH v4 20/24] PM / devfreq: tegra30: Optimize upper average " Dmitry Osipenko
2019-07-19  1:36   ` Chanwoo Choi
2019-07-19  1:59     ` Dmitry Osipenko
2019-07-19  2:06       ` Chanwoo Choi
2019-07-19  2:21         ` Dmitry Osipenko
2019-07-19  6:09           ` Chanwoo Choi
2019-07-19  6:11             ` Chanwoo Choi
2019-07-19 17:52               ` Dmitry Osipenko
2019-07-24 11:17                 ` Chanwoo Choi
2019-07-24 11:19                   ` Chanwoo Choi
2019-07-07 22:33 ` [PATCH v4 21/24] PM / devfreq: tegra30: Synchronize average count on target's update Dmitry Osipenko
2019-07-18 10:15   ` Chanwoo Choi
2019-07-19  0:31     ` Dmitry Osipenko
2019-07-19  1:40       ` Chanwoo Choi
2019-07-19 16:46         ` Dmitry Osipenko
2019-07-07 22:33 ` [PATCH v4 22/24] PM / devfreq: tegra30: Include appropriate header Dmitry Osipenko
2019-07-18  9:58   ` Chanwoo Choi
2019-07-19  0:34     ` Dmitry Osipenko
2019-07-07 22:33 ` [PATCH v4 23/24] PM / devfreq: tegra30: Increase sampling period to 16ms Dmitry Osipenko
2019-07-18 10:00   ` Chanwoo Choi
2019-07-07 22:33 ` [PATCH v4 24/24] PM / devfreq: tegra20/30: Add Dmitry as a maintainer Dmitry Osipenko
2019-07-18  9:56   ` Chanwoo Choi

Reply instructions:

You may reply publically 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=ce18694a-4281-a245-7bdf-299fedc3c724@samsung.com \
    --to=cw00.choi@samsung.com \
    --cc=digetx@gmail.com \
    --cc=jonathanh@nvidia.com \
    --cc=kyungmin.park@samsung.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=myungjoo.ham@samsung.com \
    --cc=thierry.reding@gmail.com \
    --cc=tomeu.vizoso@collabora.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

Linux-PM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pm/0 linux-pm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pm linux-pm/ https://lore.kernel.org/linux-pm \
		linux-pm@vger.kernel.org
	public-inbox-index linux-pm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git