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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM list <linux-pm@vger.kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Juri Lelli <juri.lelli@arm.com>
Subject: [PATCH 1/9] cpufreq: governor: Simplify gov_cancel_work() slightly
Date: Mon, 15 Feb 2016 02:12:56 +0100	[thread overview]
Message-ID: <1696919.WxyrSFSFde@vostro.rjw.lan> (raw)
In-Reply-To: <3329748.lhJgppdTt9@vostro.rjw.lan>

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The atomic work counter incrementation in gov_cancel_work() is not
necessary any more, because work items won't be queued up after
gov_clear_update_util() anyway, so drop it along with the comment
about how it may be missed by the gov_clear_update_util().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

This is a new version of https://patchwork.kernel.org/patch/8291021/ .

Changes from the previous version:
- Rebase.

---
 drivers/cpufreq/cpufreq_governor.c |    8 --------
 1 file changed, 8 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq_governor.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c
+++ linux-pm/drivers/cpufreq/cpufreq_governor.c
@@ -300,13 +300,6 @@ static void gov_cancel_work(struct cpufr
 {
 	struct policy_dbs_info *policy_dbs = policy->governor_data;
 
-	/* Tell dbs_update_util_handler() to skip queuing up work items. */
-	atomic_inc(&policy_dbs->work_count);
-	/*
-	 * If dbs_update_util_handler() is already running, it may not notice
-	 * the incremented work_count, so wait for it to complete to prevent its
-	 * work item from being queued up after the cancel_work_sync() below.
-	 */
 	gov_clear_update_util(policy_dbs->policy);
 	irq_work_sync(&policy_dbs->irq_work);
 	cancel_work_sync(&policy_dbs->work);
@@ -369,7 +362,6 @@ static void dbs_update_util_handler(stru
 	 * The work may not be allowed to be queued up right now.
 	 * Possible reasons:
 	 * - Work has already been queued up or is in progress.
-	 * - The governor is being stopped.
 	 * - It is too early (too little time from the previous sample).
 	 */
 	if (atomic_inc_return(&policy_dbs->work_count) == 1) {

  reply	other threads:[~2016-02-15  1:21 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-15  1:08 [PATCH 0/9] cpufreq governor improvements Rafael J. Wysocki
2016-02-15  1:12 ` Rafael J. Wysocki [this message]
2016-02-15  5:40   ` [PATCH 1/9] cpufreq: governor: Simplify gov_cancel_work() slightly Viresh Kumar
2016-02-15  1:13 ` [PATCH 2/9] cpufreq: governor: Avoid atomic operations in hot paths Rafael J. Wysocki
2016-02-15  6:17   ` Viresh Kumar
2016-02-15  8:20   ` Viresh Kumar
2016-02-15  1:15 ` [PATCH 3/9] cpufreq: governor: Fix nice contribution computation in dbs_check_cpu() Rafael J. Wysocki
2016-02-15  8:29   ` Viresh Kumar
2016-02-15  1:18 ` [PATCH 4/9] cpufreq: governor: Clean up load-related computations Rafael J. Wysocki
2016-02-15  8:33   ` Viresh Kumar
2016-02-15  1:19 ` [PATCH 5/9] cpufreq: governor: Get rid of the ->gov_check_cpu callback Rafael J. Wysocki
2016-02-15  8:52   ` Viresh Kumar
2016-02-15  1:20 ` [PATCH 6/9] cpufreq: governor: Reset sample delay in store_sampling_rate() Rafael J. Wysocki
2016-02-15  8:53   ` Viresh Kumar
2016-02-15  1:20 ` [PATCH 7/9] cpufreq: governor: Move rate_mult to struct policy_dbs Rafael J. Wysocki
2016-02-15  8:56   ` Viresh Kumar
2016-02-15  1:21 ` [PATCH 8/9] cpufreq: ondemand: Simplify conditionals in od_dbs_timer() Rafael J. Wysocki
2016-02-15  8:57   ` Viresh Kumar
2016-02-15  1:22 ` [PATCH 9/9] cpufreq: governor: Use microseconds in sample delay computations Rafael J. Wysocki
2016-02-15  8:58   ` Viresh Kumar

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