linux-kernel - [PATCH V2 3/4] intel_pstate: Ignore scheduler cpufreq callbacks on remote CPUs

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Message-Id: <a33ba3746dacce67a7c2e17b64e54ee89f64a3bc.1498712046.git.viresh.kumar@linaro.org>
Date:   Thu, 29 Jun 2017 10:56:32 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Rafael Wysocki <rjw@...ysocki.net>, Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        Len Brown <lenb@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>
Cc:     linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        linux-kernel@...r.kernel.org, smuckle.linux@...il.com,
        juri.lelli@....com, Morten.Rasmussen@....com,
        patrick.bellasi@....com, eas-dev@...ts.linaro.org
Subject: [PATCH V2 3/4] intel_pstate: Ignore scheduler cpufreq callbacks on remote CPUs

From: Steve Muckle <smuckle.linux@...il.com>

In preparation for the scheduler cpufreq callback happening on remote
CPUs, check for this case in intel_pstate which currently requires the
callback run on the local CPU. Such callbacks are ignored for now.

Signed-off-by: Steve Muckle <smuckle.linux@...il.com>
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/cpufreq/intel_pstate.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 4ce501148790..7a2a8ee579ef 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1755,6 +1755,9 @@ static void intel_pstate_update_util(struct update_util_data *data, u64 time,
 	struct cpudata *cpu = container_of(data, struct cpudata, update_util);
 	u64 delta_ns;
 
+	if (smp_processor_id() != data->cpu)
+		return;
+
 	if (flags & SCHED_CPUFREQ_IOWAIT) {
 		cpu->iowait_boost = int_tofp(1);
 	} else if (cpu->iowait_boost) {
-- 
2.13.0.71.gd7076ec9c9cb