Commit 82b4e03e authored Jun 23, 2017 by Len Brown Committed by Rafael J. Wysocki Jun 27, 2017

intel_pstate: skip scheduler hook when in "performance" mode



When the governor is set to "performance", intel_pstate does not
need the scheduler hook for doing any calculations.  Under these
conditions, its only purpose is to continue to maintain
cpufreq/scaling_cur_freq.

The cpufreq/scaling_cur_freq sysfs attribute is now provided by
shared x86 cpufreq code on modern x86 systems, including
all systems supported by the intel_pstate driver.

So in "performance" governor mode, the scheduler hook can be skipped.
This applies to both in Software and Hardware P-state control modes.

Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 62611cb9

drivers/cpufreq/intel_pstate.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -2044,9 +2044,9 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
		*/
		intel_pstate_clear_update_util_hook(policy->cpu);
		intel_pstate_max_within_limits(cpu);
		}

		} else {
		intel_pstate_set_update_util_hook(policy->cpu);
		}

		if (hwp_active)
		intel_pstate_hwp_set(policy->cpu);