Patch "cpufreq: schedutil: Fix per-CPU structure initialization in sugov_start()" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

cpufreq: schedutil: Fix per-CPU structure initialization in sugov_start()

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-fix-per-cpu-structure-initialization-in-sugov_start.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.

From: "Rafael J. Wysocki" <[email protected]>
Date: Sun, 19 Mar 2017 14:30:02 +0100
Subject: cpufreq: schedutil: Fix per-CPU structure initialization in sugov_start()

From: Rafael J. Wysocki <[email protected]>

commit 4296f23ed49a15d36949458adcc66ff993dee2a8 upstream.

sugov_start() only initializes struct sugov_cpu per-CPU structures for shared policies, but it should do that for single-CPU policies too.

That in particular makes the IO-wait boost mechanism work in the cases when cpufreq policies correspond to individual CPUs.

---
 kernel/sched/cpufreq_schedutil.c |   20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

@@ -507,20 +507,14 @@ static int sugov_start(struct cpufreq_po
 	for_each_cpu(cpu, policy->cpus) {
 		struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
 
+		memset(sg_cpu, 0, sizeof(*sg_cpu));
 		sg_cpu->sg_policy = sg_policy;
-		if (policy_is_shared(policy)) {
-			sg_cpu->util = 0;
-			sg_cpu->max = 0;
-			sg_cpu->flags = SCHED_CPUFREQ_RT;
-			sg_cpu->last_update = 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,
-						     sugov_update_shared);
-		} else {
-			cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util,
-						     sugov_update_single);
-		}
+		sg_cpu->flags = SCHED_CPUFREQ_RT;
+		sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq;
+		cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util,
+					     policy_is_shared(policy) ?
+							sugov_update_shared :
+							sugov_update_single);
 	}
 	return 0;
 }

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