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cpufreq: intel_pstate: Adjust policy->cur in active mode to policy

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Since arch_freq_get_on_cpu() on x86 falls back to cpufreq_quick_get(),
which effectively causes policy->cur to be returned when intel_pstate
is used, adjust intel_pstate_set_policy() to set policy->cur to reflect
the P-state that is actually going to be requested in the "performance"
policy case instead of setting it to policy->min (which is confusing
because it causes scaling_cur_freq to show the minimum frequency while
the CPU is likely running at the maximum one).

For this purpose, rearrange intel_pstate_set_policy() to handle the HWP
case separately, to avoid calling intel_pstate_set_pstate() pointlessly
with HWP enabled, and use the observation that with HWP enabled in the
active mode, the utilization update hook is only needed when HWP boost
is used and the policy is not "performance".

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Doug Smythies <dsmythies@telus.net>
Tested-by: Doug Smythies <dsmythies@telus.net>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://patch.msgid.link/5144014.31r3eYUQgx@rafael.j.wysocki
This commit is contained in:
Rafael J. Wysocki
2026-07-29 20:40:08 +02:00
parent 53d08ba34e
commit 9e4cb21f29
1 changed files with 24 additions and 15 deletions
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39
drivers/cpufreq/intel_pstate.c
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@@ -2870,6 +2870,7 @@ static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
static int intel_pstate_set_policy(struct cpufreq_policy *policy)
{
unsigned int freq = policy->min;
struct cpudata *cpu;
if (!policy->cpuinfo.max_freq)
@@ -2885,7 +2886,23 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
intel_pstate_update_perf_limits(cpu, policy->min, policy->max);
if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE) {
if (hwp_active) {
/*
* The active mode only requires an update util hook if HWP
* boost is used and the policy is not "performance".
*/
if (hwp_boost && cpu->policy != CPUFREQ_POLICY_PERFORMANCE) {
intel_pstate_set_update_util_hook(policy->cpu);
} else {
intel_pstate_clear_update_util_hook(policy->cpu);
if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE) {
freq = cpu->max_perf_ratio * cpu->pstate.scaling;
if (cpu->pstate.scaling != cpu->pstate.perf_ctl_scaling)
freq = rounddown(freq, cpu->pstate.perf_ctl_scaling);
}
}
intel_pstate_hwp_set(policy->cpu);
} else if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE) {
int pstate = max(cpu->pstate.min_pstate, cpu->max_perf_ratio);
/*
@@ -2894,25 +2911,17 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
*/
intel_pstate_clear_update_util_hook(policy->cpu);
intel_pstate_set_pstate(cpu, pstate);
freq = pstate * cpu->pstate.scaling;
} else {
intel_pstate_set_update_util_hook(policy->cpu);
}
if (hwp_active) {
/*
* When hwp_boost was active before and dynamically it
* was turned off, in that case we need to clear the
* update util hook.
*/
if (!hwp_boost)
intel_pstate_clear_update_util_hook(policy->cpu);
intel_pstate_hwp_set(policy->cpu);
}
/*
* policy->cur is never updated with the intel_pstate driver, but it
* is used as a stale frequency value. So, keep it within limits.
* policy->cur is never updated in the intel_pstate driver, but it is
* used as a stale frequency value, so set it to reflect the actual
* requested P-state in the "performance" policy case and to the min
* otherwise.
*/
policy->cur = policy->min;
policy->cur = freq;
mutex_unlock(&intel_pstate_limits_lock);