From: Viresh Kumar <viresh.kumar@linaro.org>
To: Rafael Wysocki <rjw@rjwysocki.net>
Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org,
Viresh Kumar <viresh.kumar@linaro.org>,
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH 6/6] cpufreq: ondemand: update update_sampling_rate() to make it more efficient
Date: Thu, 29 Oct 2015 17:57:25 +0530 [thread overview]
Message-ID: <a15399b18a06bbe3e22e9e7b01e8e4a7a61a044f.1446121217.git.viresh.kumar@linaro.org> (raw)
In-Reply-To: <cover.1446121217.git.viresh.kumar@linaro.org>
In-Reply-To: <cover.1446121217.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 9e0293c23285..6eac39124894 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -251,6 +251,7 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
struct cpufreq_policy *policy;
struct cpu_common_dbs_info *shared;
unsigned long next_sampling, appointed_at;
+ struct cpumask cpumask;
int cpu;
od_tuners->sampling_rate = new_rate = max(new_rate,
@@ -261,7 +262,9 @@ 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) {
dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
cdbs = &dbs_info->cdbs;
shared = cdbs->shared;
@@ -275,6 +278,9 @@ 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
@@ -284,6 +290,10 @@ 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:[~2015-10-29 12:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1446121217.git.viresh.kumar@linaro.org>
2015-10-29 12:27 ` [PATCH 1/6] cpufreq: ondemand: Update sampling rate only for concerned policies Viresh Kumar
2015-12-03 2:16 ` Rafael J. Wysocki
2015-10-29 12:27 ` [PATCH 2/6] cpufreq: ondemand: Work is guaranteed to be pending Viresh Kumar
2015-10-29 12:27 ` [PATCH 3/6] cpufreq: governor: Pass policy as argument to ->gov_dbs_timer() Viresh Kumar
2015-10-29 12:27 ` [PATCH 4/6] cpufreq: governor: initialize/destroy timer_mutex with 'shared' Viresh Kumar
2015-10-29 12:27 ` [PATCH 5/6] cpufreq: governor: replace per-cpu delayed work with timers Viresh Kumar
2015-10-30 20:46 ` Ashwin Chaugule
2015-10-31 2:36 ` Viresh Kumar
2015-11-03 19:01 ` Ashwin Chaugule
2015-11-30 12:05 ` Lucas Stach
2015-11-30 13:35 ` Viresh Kumar
2015-10-29 12:27 ` Viresh Kumar [this message]
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