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Patch "cpufreq: schedutil: move cached_raw_freq to struct sugov_policy" has been added to the 4.9-stable tree

PATCH [email protected] 1 participant 1 message Jun 12, 2017

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Stable branch Scheduler CPU frequency scaling framework
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This is a note to let you know that I've just added the patch titled

cpufreq: schedutil: move cached_raw_freq to struct sugov_policy

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
cpufreq-schedutil-move-cached_raw_freq-to-struct-sugov_policy.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 6c4f0fa643cb9e775dcc976e3db00d649468ff1d Mon Sep 17 00:00:00 2001

From: Viresh Kumar <[email protected]>
Date: Thu, 2 Mar 2017 14:03:20 +0530
Subject: cpufreq: schedutil: move cached_raw_freq to struct sugov_policy

From: Viresh Kumar <[email protected]>

commit 6c4f0fa643cb9e775dcc976e3db00d649468ff1d upstream.

cached_raw_freq applies to the entire cpufreq policy and not individual CPUs. Apart from wasting per-cpu memory, it is actually wrong to keep it in struct sugov_cpu as we may end up comparing next_freq with a stale cached_raw_freq of a random CPU.

Move cached_raw_freq to struct sugov_policy.

Fixes 5cbea46984d6 (cpufreq: schedutil: map raw required frequency to driver frequency)
Signed-off-by Viresh Kumar <[email protected]>
Signed-off-by Rafael J. Wysocki <[email protected]>
Signed-off-by Amit Pundir <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 kernel/sched/cpufreq_schedutil.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
kernel/sched/cpufreq_schedutil.c +4 -4
@@ -32,6 +32,7 @@ struct sugov_policy {
 	u64 last_freq_update_time;
 	s64 freq_update_delay_ns;
 	unsigned int next_freq;
+	unsigned int cached_raw_freq;
 
 	/* The next fields are only needed if fast switch cannot be used. */
 	struct irq_work irq_work;

@@ -46,7 +47,6 @@ struct sugov_cpu {
 	struct update_util_data update_util;
 	struct sugov_policy *sg_policy;
 
-	unsigned int cached_raw_freq;
 	unsigned long iowait_boost;
 	unsigned long iowait_boost_max;
 	u64 last_update;

@@ -140,9 +140,9 @@ static unsigned int get_next_freq(struct
 
 	freq = (freq + (freq >> 2)) * util / max;
 
-	if (freq == sg_cpu->cached_raw_freq && sg_policy->next_freq != UINT_MAX)
+	if (freq == sg_policy->cached_raw_freq && sg_policy->next_freq != UINT_MAX)
 		return sg_policy->next_freq;
-	sg_cpu->cached_raw_freq = freq;
+	sg_policy->cached_raw_freq = freq;
 	return cpufreq_driver_resolve_freq(policy, freq);
 }
 

@@ -502,6 +502,7 @@ static int sugov_start(struct cpufreq_po
 	sg_policy->next_freq = UINT_MAX;
 	sg_policy->work_in_progress = false;
 	sg_policy->need_freq_update = false;
+	sg_policy->cached_raw_freq = 0;
 
 	for_each_cpu(cpu, policy->cpus) {
 		struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);

@@ -512,7 +513,6 @@ static int sugov_start(struct cpufreq_po
 			sg_cpu->max = 0;
 			sg_cpu->flags = SCHED_CPUFREQ_RT;
 			sg_cpu->last_update = 0;
-			sg_cpu->cached_raw_freq = 0;
 			sg_cpu->iowait_boost = 0;
 			sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq;
 			cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util,

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/cpufreq-schedutil-move-cached_raw_freq-to-struct-sugov_policy.patch queue-4.9/cpufreq-schedutil-fix-per-cpu-structure-initialization-in-sugov_start.patch queue-4.9/cpufreq-cpufreq_register_driver-should-return-enodev-if-init-fails.patch