From 27d80e0f8b8dff97503fc0061754b1d3800cb961 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 7 Jul 2026 19:19:55 +0200 Subject: [PATCH 1/2] cpufreq: intel_pstate: Set non-turbo capacity to HWP_GUARANTEED_PERF() Setting cpu->capacity_perf to cpu->pstate.max_pstate_physical in the "no turbo" case is inconsistent with what happens elsewhere in the driver and causes arch_scale_cpu_capacity() to be incorrect. It also skews arch_scale_freq_capacity() which ends up differing from 1024 for the guaranteed P-state. Address that by setting capacity_perf to HWP_GUARANTEED_PERF() in the "no turbo" case. Fixes: 929ebc93ccaa ("cpufreq: intel_pstate: Set asymmetric CPU capacity on hybrid systems") Signed-off-by: Rafael J. Wysocki Tested-by: Ricardo Neri Cc: All applicable Link: https://patch.msgid.link/12928972.O9o76ZdvQC@rafael.j.wysocki --- drivers/cpufreq/intel_pstate.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 5a0eeb84d382..6e984c114d96 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1058,12 +1058,14 @@ static void hybrid_clear_cpu_capacity(unsigned int cpunum) static void hybrid_get_capacity_perf(struct cpudata *cpu) { + u64 hwp_cap = READ_ONCE(cpu->hwp_cap_cached); + if (READ_ONCE(global.no_turbo)) { - cpu->capacity_perf = cpu->pstate.max_pstate_physical; + cpu->capacity_perf = HWP_GUARANTEED_PERF(hwp_cap); return; } - cpu->capacity_perf = HWP_HIGHEST_PERF(READ_ONCE(cpu->hwp_cap_cached)); + cpu->capacity_perf = HWP_HIGHEST_PERF(hwp_cap); } static void hybrid_set_capacity_of_cpus(void) From d2d5c129d07ea8eb91cd8a8633b5774116c4d171 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 7 Jul 2026 19:25:39 +0200 Subject: [PATCH 2/2] cpufreq: Make cpufreq_update_pressure() fall back to cpuinfo.max_freq If arch_scale_freq_ref() is not defined for a given arch (like x86, for example), cpufreq_update_pressure() will always set cpufreq_pressure to zero for all CPUs in the system, which is generally problematic on systems with asymmetric capacity [1]. However, in the absence of arch_scale_freq_ref(), it is reasonable to assume that cpuinfo.max_freq is the maximum sustainable frequency for the given cpufreq policy. Moreover, there are cases in which arch_scale_freq_ref() would need to be defined to return essentially the cpuinfo.max_freq value anyway (for example, intel_pstate on hybrid platforms). For the above reasons, update cpufreq_update_pressure() to fall back to using cpuinfo.max_freq as the reference frequency if zero is returned by arch_scale_freq_ref(). Fixes: 75d659317bb1 ("cpufreq: Add a cpufreq pressure feedback for the scheduler") Link: https://lore.kernel.org/lkml/CAKfTPtBuRLfYNnR4w--cFZYZy-R8gaPEgVwCcaMmbCcJ2H-muQ@mail.gmail.com/ [1] Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Reviewed-by: Zhongqiu Han Tested-by: Ricardo Neri # cluster scheduling Acked-by: Vincent Guittot Link: https://patch.msgid.link/5086499.GXAFRqVoOG@rafael.j.wysocki --- drivers/cpufreq/cpufreq.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 507224c9ecd3..b898b6544069 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2586,6 +2586,9 @@ static void cpufreq_update_pressure(struct cpufreq_policy *policy) cpu = cpumask_first(policy->related_cpus); max_freq = arch_scale_freq_ref(cpu); + if (!max_freq) + max_freq = policy->cpuinfo.max_freq; + capped_freq = policy->max; /*