Commit cad30467 authored Dec 30, 2016 by Rafael J. Wysocki

cpufreq: intel_pstate: Use locking in intel_cpufreq_verify_policy()



Race conditions are possible if intel_cpufreq_verify_policy()
is executed in parallel with global limits updates from sysfs,
so the invocation of intel_pstate_update_perf_limits() in it
should be carried out under intel_pstate_limits_lock.

Make that happen.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

parent aa439248

drivers/cpufreq/intel_pstate.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -2103,8 +2103,12 @@ static int intel_cpufreq_verify_policy(struct cpufreq_policy *policy)
		if (per_cpu_limits)
		perf_limits = cpu->perf_limits;

		mutex_lock(&intel_pstate_limits_lock);

		intel_pstate_update_perf_limits(policy, perf_limits);

		mutex_unlock(&intel_pstate_limits_lock);

		return 0;
		}