diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 3 | ||||
| -rw-r--r-- | Documentation/admin-guide/pm/intel_pstate.rst | 3 | ||||
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 9 |
3 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fb8752b42ec8..77e671e55993 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2316,6 +2316,9 @@ per_cpu_perf_limits Allow per-logical-CPU P-State performance control limits using cpufreq sysfs interface + no_cas + Do not enable capacity-aware scheduling (CAS) on + hybrid systems intremap= [X86-64,Intel-IOMMU,EARLY] on enable Interrupt Remapping (default) diff --git a/Documentation/admin-guide/pm/intel_pstate.rst b/Documentation/admin-guide/pm/intel_pstate.rst index bf13ad25a32f..78fc83ed2a7e 100644 --- a/Documentation/admin-guide/pm/intel_pstate.rst +++ b/Documentation/admin-guide/pm/intel_pstate.rst @@ -696,6 +696,9 @@ of them have to be prepended with the ``intel_pstate=`` prefix. Use per-logical-CPU P-State limits (see `Coordination of P-state Limits`_ for details). +``no_cas`` + Do not enable capacity-aware scheduling (CAS) which is enabled by + default on hybrid systems. Diagnostics and Tuning ====================== diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 9c4cc01fd51a..bc31e9b9b660 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -936,6 +936,8 @@ static struct freq_attr *hwp_cpufreq_attrs[] = { NULL, }; +static bool no_cas __ro_after_init; + static struct cpudata *hybrid_max_perf_cpu __read_mostly; /* * Protects hybrid_max_perf_cpu, the capacity_perf fields in struct cpudata, @@ -1041,6 +1043,10 @@ static void hybrid_refresh_cpu_capacity_scaling(void) static void hybrid_init_cpu_capacity_scaling(bool refresh) { + /* Bail out if enabling capacity-aware scheduling is prohibited. */ + if (no_cas) + return; + /* * If hybrid_max_perf_cpu is set at this point, the hybrid CPU capacity * scaling has been enabled already and the driver is just changing the @@ -3835,6 +3841,9 @@ static int __init intel_pstate_setup(char *str) if (!strcmp(str, "no_hwp")) no_hwp = 1; + if (!strcmp(str, "no_cas")) + no_cas = true; + if (!strcmp(str, "force")) force_load = 1; if (!strcmp(str, "hwp_only")) |