The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 4296f23ed49a15d36949458adcc66ff993dee2a8 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> Date: Sun, 19 Mar 2017 14:30:02 +0100 Subject: [PATCH] cpufreq: schedutil: Fix per-CPU structure initialization in sugov_start() 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. Fixes: 21ca6d2c52f8 (cpufreq: schedutil: Add iowait boosting) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> Cc: 4.9+ <stable@xxxxxxxxxxxxxxx> # 4.9+ diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index cd7cd489f739..54c577578da6 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -584,20 +584,14 @@ static int sugov_start(struct cpufreq_policy *policy) 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; }