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cpufreq: intel_pstate: Use likely() optimization in intel_pstate_sample() 

The comment above the condition `if (cpu->last_sample_time)` clearly
indicates that the branch is taken for the vast majority of invocations
after the first sample in a cycle. The first sample is a one-time
initialization case.

Add likely() hint to the condition to improve branch prediction for
this performance-critical path in intel_pstate_sample().

Signed-off-by: Yaxiong Tian <tianyaxiong@kylinos.cn>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Yaxiong Tian 2025-09-12 15:35:02 +08:00 committed by Rafael J. Wysocki
parent 7c0dde86c1
commit 02d09026a8
1 changed files with 1 additions and 1 deletions
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2
drivers/cpufreq/intel_pstate.c
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@ -2542,7 +2542,7 @@ static inline bool intel_pstate_sample(struct cpudata *cpu, u64 time)
* that sample.time will always be reset before setting the utilization * that sample.time will always be reset before setting the utilization
* update hook and make the caller skip the sample then. * update hook and make the caller skip the sample then.
*/ */
if (cpu->last_sample_time) { if (likely(cpu->last_sample_time)) {
intel_pstate_calc_avg_perf(cpu); intel_pstate_calc_avg_perf(cpu);
return true; return true;
} }