Messages in this thread Patch in this message | | | From | Len Brown <> | Subject | [PATCH 4/5] intel_pstate: skip scheduler hook when in "performance" mode. | Date | Wed, 7 Jun 2017 19:39:15 -0700 |
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From: Len Brown <len.brown@intel.com>
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.
But the cpufreq/scaling_cur_freq sysfs attribute is now provided by the x86 cpufreq core on all 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> --- drivers/cpufreq/intel_pstate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 5d67780..0ff3a4b 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2025,10 +2025,10 @@ 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); } - intel_pstate_set_update_util_hook(policy->cpu); - if (hwp_active) intel_pstate_hwp_set(policy->cpu); -- 2.7.4
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