From 1fedbb589448bee9f20bb2ed9c850d1d2cf9963c Mon Sep 17 00:00:00 2001 From: Yaxiong Tian Date: Tue, 3 Feb 2026 10:48:52 +0800 Subject: [PATCH] cpufreq: intel_pstate: Enable asym capacity only when CPU SMT is not possible According to the description in the intel_pstate.rst documentation, Capacity-Aware Scheduling and Energy-Aware Scheduling are only supported on a hybrid processor without SMT. Previously, the system used sched_smt_active() for judgment, which is not a strict condition because users can switch it on or off via /sys at any time. This could lead to incorrect driver settings in certain scenarios. For example, on a CPU that supports SMT, a user can disable SMT via the nosmt parameter to enable asym capacity, and then re-enable SMT via /sys. In such cases, some settings in the driver would no longer be correct. To address this issue, replace sched_smt_active() with cpu_smt_possible(), and only enable asym capacity when CPU SMT is not possible. Fixes: 929ebc93ccaa ("cpufreq: intel_pstate: Set asymmetric CPU capacity on hybrid systems") Signed-off-by: Yaxiong Tian [ rjw: Subject and changelog edits ] Link: https://patch.msgid.link/20260203024852.301066-1-tianyaxiong@kylinos.cn Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index ec4abe3745736..1625ec2d0d06a 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1161,7 +1161,7 @@ static void hybrid_init_cpu_capacity_scaling(bool refresh) * the capacity of SMT threads is not deterministic even approximately, * do not do that when SMT is in use. */ - if (hwp_is_hybrid && !sched_smt_active() && arch_enable_hybrid_capacity_scale()) { + if (hwp_is_hybrid && !cpu_smt_possible() && arch_enable_hybrid_capacity_scale()) { hybrid_refresh_cpu_capacity_scaling(); /* * Disabling ITMT causes sched domains to be rebuilt to disable asym -- 2.47.3