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From: Dmitry Osipenko <digetx@gmail.com>
To: 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>
Cc: linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v4 18/24] PM / devfreq: tegra30: Optimize CPUFreq notifier
Date: Mon,  8 Jul 2019 01:32:57 +0300
Message-ID: <20190707223303.6755-19-digetx@gmail.com> (raw)
In-Reply-To: <20190707223303.6755-1-digetx@gmail.com>

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(-)

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
-- 
2.22.0


  parent 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 ` Dmitry Osipenko [this message]
2019-07-18  9:48   ` [PATCH v4 18/24] PM / devfreq: tegra30: Optimize CPUFreq notifier Chanwoo Choi
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

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