Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH 3/4] cpufreq: intel_pstate: Add ->offline and ->online callbacks | Date | Thu, 20 Aug 2020 18:38:01 +0200 |
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From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Add ->offline and ->online driver callbacksto to do the cleanup before taking a CPU offline and to restore its working configuration when it goes back online, respectively, to avoid invoking the ->init callback on every CPU online which is quite a bit of unnecessary overhead.
Define ->offline and ->online so that they can be used in the passive as well as in the active mode and because ->offline will do the majority of ->stop_cpu work, the passive mode does not need that callback any more, so drop it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> --- drivers/cpufreq/intel_pstate.c | 38 ++++++++++++++++++++++++++++------ 1 file changed, 32 insertions(+), 6 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 3d18934fa975..aca0587b176f 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2297,28 +2297,51 @@ static int intel_pstate_verify_policy(struct cpufreq_policy_data *policy) return 0; } -static void intel_cpufreq_stop_cpu(struct cpufreq_policy *policy) +static int intel_pstate_cpu_offline(struct cpufreq_policy *policy) { + pr_debug("CPU %d going offline\n", policy->cpu); + + intel_pstate_exit_perf_limits(policy); + + /* + * If the CPU is an SMT thread and it goes offline with the performance + * settings different from the minimum, it will prevent its sibling + * from getting to lower performance levels, so force the minimum + * performance on CPU offline to prevent that form happening. + */ if (hwp_active) intel_pstate_hwp_force_min_perf(policy->cpu); else intel_pstate_set_min_pstate(all_cpu_data[policy->cpu]); + + return 0; +} + +static int intel_pstate_cpu_online(struct cpufreq_policy *policy) +{ + pr_debug("CPU %d going online\n", policy->cpu); + + intel_pstate_init_acpi_perf_limits(policy); + + if (hwp_active) + wrmsrl_on_cpu(policy->cpu, MSR_HWP_REQUEST, + all_cpu_data[policy->cpu]->hwp_req_cached); + + return 0; } static void intel_pstate_stop_cpu(struct cpufreq_policy *policy) { - pr_debug("CPU %d exiting\n", policy->cpu); + pr_debug("CPU %d stopping\n", policy->cpu); intel_pstate_clear_update_util_hook(policy->cpu); if (hwp_active) intel_pstate_hwp_save_state(policy); - - intel_cpufreq_stop_cpu(policy); } static int intel_pstate_cpu_exit(struct cpufreq_policy *policy) { - intel_pstate_exit_perf_limits(policy); + pr_debug("CPU %d exiting\n", policy->cpu); policy->fast_switch_possible = false; @@ -2398,6 +2421,8 @@ static struct cpufreq_driver intel_pstate = { .init = intel_pstate_cpu_init, .exit = intel_pstate_cpu_exit, .stop_cpu = intel_pstate_stop_cpu, + .offline = intel_pstate_cpu_offline, + .online = intel_pstate_cpu_online, .update_limits = intel_pstate_update_limits, .name = "intel_pstate", }; @@ -2652,7 +2677,8 @@ static struct cpufreq_driver intel_cpufreq = { .fast_switch = intel_cpufreq_fast_switch, .init = intel_cpufreq_cpu_init, .exit = intel_cpufreq_cpu_exit, - .stop_cpu = intel_cpufreq_stop_cpu, + .offline = intel_pstate_cpu_offline, + .online = intel_pstate_cpu_online, .update_limits = intel_pstate_update_limits, .name = "intel_cpufreq", }; -- 2.26.2
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