From: Viresh Kumar <viresh.kumar@linaro.org>
To: Rafael Wysocki <rjw@rjwysocki.net>
Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org,
ashwin.chaugule@linaro.org,
Viresh Kumar <viresh.kumar@linaro.org>,
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH V2 6/6] cpufreq: ondemand: update update_sampling_rate() to make it more efficient
Date: Thu, 3 Dec 2015 09:37:54 +0530 [thread overview]
Message-ID: <5b9fffd163d07be79943615d069147e801975e0c.1449115453.git.viresh.kumar@linaro.org> (raw)
In-Reply-To: <cover.1449115453.git.viresh.kumar@linaro.org>
In-Reply-To: <cover.1449115453.git.viresh.kumar@linaro.org>
Currently update_sampling_rate() runs over each online CPU and
cancels/queues timers on all policy->cpus every time. This should be
done just once for any cpu belonging to a policy.
Create a cpumask and keep on clearing it as and when we process
policies, so that we don't have to traverse through all CPUs of the same
policy.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/cpufreq_ondemand.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index f879012cf849..eae51070c034 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -246,6 +246,7 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
unsigned int new_rate)
{
struct od_dbs_tuners *od_tuners = dbs_data->tuners;
+ struct cpumask cpumask;
int cpu;
od_tuners->sampling_rate = new_rate = max(new_rate,
@@ -256,7 +257,9 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
*/
mutex_lock(&od_dbs_cdata.mutex);
- for_each_online_cpu(cpu) {
+ cpumask_copy(&cpumask, cpu_online_mask);
+
+ for_each_cpu(cpu, &cpumask) {
struct cpufreq_policy *policy;
struct od_cpu_dbs_info_s *dbs_info;
struct cpu_dbs_info *cdbs;
@@ -276,6 +279,9 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
policy = shared->policy;
+ /* clear all CPUs of this policy */
+ cpumask_andnot(&cpumask, &cpumask, policy->cpus);
+
/*
* Update sampling rate for CPUs whose policy is governed by
* dbs_data. In case of governor_per_policy, only a single
@@ -285,6 +291,10 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
if (dbs_data != policy->governor_data)
continue;
+ /*
+ * Checking this for any CPU should be fine, timers for all of
+ * them are scheduled together.
+ */
next_sampling = jiffies + usecs_to_jiffies(new_rate);
appointed_at = dbs_info->cdbs.timer.expires;
--
2.6.2.198.g614a2ac
prev parent reply other threads:[~2015-12-03 4:09 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1449115453.git.viresh.kumar@linaro.org>
2015-12-03 4:07 ` [PATCH V2 1/6] cpufreq: ondemand: Update sampling rate only for concerned policies Viresh Kumar
2015-12-03 4:07 ` [PATCH V2 2/6] cpufreq: ondemand: Work is guaranteed to be pending Viresh Kumar
2015-12-03 4:07 ` [PATCH V2 3/6] cpufreq: governor: Pass policy as argument to ->gov_dbs_timer() Viresh Kumar
2015-12-03 4:07 ` [PATCH V2 4/6] cpufreq: governor: initialize/destroy timer_mutex with 'shared' Viresh Kumar
2015-12-03 4:07 ` [PATCH V2 5/6] cpufreq: governor: replace per-cpu delayed work with timers Viresh Kumar
2015-12-04 1:18 ` Rafael J. Wysocki
2015-12-04 6:11 ` Viresh Kumar
2015-12-05 2:14 ` Rafael J. Wysocki
2015-12-05 4:10 ` Viresh Kumar
2015-12-07 1:28 ` Rafael J. Wysocki
2015-12-07 7:50 ` Viresh Kumar
2015-12-07 22:43 ` Rafael J. Wysocki
2015-12-07 23:17 ` Rafael J. Wysocki
2015-12-08 0:39 ` [PATCH][experimantal] cpufreq: governor: Use an atomic variable for synchronization Rafael J. Wysocki
2015-12-08 6:59 ` Viresh Kumar
2015-12-08 13:30 ` Rafael J. Wysocki
2015-12-08 13:36 ` Viresh Kumar
2015-12-08 14:19 ` Rafael J. Wysocki
2015-12-08 13:55 ` Viresh Kumar
2015-12-08 14:30 ` Rafael J. Wysocki
2015-12-08 14:56 ` Viresh Kumar
2015-12-08 16:42 ` Rafael J. Wysocki
2015-12-08 16:34 ` Viresh Kumar
2015-12-08 6:46 ` [PATCH V2 5/6] cpufreq: governor: replace per-cpu delayed work with timers Viresh Kumar
2015-12-08 6:56 ` Viresh Kumar
2015-12-08 13:18 ` Rafael J. Wysocki
2015-12-08 13:30 ` Viresh Kumar
2015-12-08 14:04 ` Rafael J. Wysocki
2015-12-04 6:13 ` [PATCH V3 " Viresh Kumar
2015-12-09 2:04 ` [PATCH V4 " Viresh Kumar
2015-12-09 22:06 ` Rafael J. Wysocki
2015-12-10 2:36 ` Viresh Kumar
2015-12-10 22:17 ` Rafael J. Wysocki
2015-12-11 1:42 ` Viresh Kumar
2015-12-03 4:07 ` Viresh Kumar [this message]
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