linux-kernel - [RFC 8/9] intel_pstate: ignore scheduler cpufreq callbacks on remote CPUs

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Message-Id: <fdd9ba5de92726cc953d36c0a84f68dda5356dd3.1489058244.git.viresh.kumar@linaro.org>
Date:   Thu,  9 Mar 2017 17:15:18 +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:     linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        smuckle.linux@...il.com, juri.lelli@....com,
        Morten.Rasmussen@....com, patrick.bellasi@....com,
        eas-dev@...ts.linaro.org
Subject: [RFC 8/9] 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 3d37219a0dd7..bd60f1cd7ea6 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1930,6 +1930,9 @@ 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 (pstate_funcs.get_target_pstate == get_target_pstate_use_cpu_load) {
 		if (flags & SCHED_CPUFREQ_IOWAIT) {
 			cpu->iowait_boost = int_tofp(1);
-- 
2.7.1.410.g6faf27b