On Friday, November 16, 2018 11:24:19 PM CET Srinivas Pandruvada wrote:
> Force HWP Request MAX = HWP Request MIN = HWP Capability MIN and EPP to
> 0xFF. In this way the performance limits on the offlined CPU will not
> influence performance limits on its sibling CPU, which is still online.
>
> If the sibling CPU is calling for higher performance, it will impact the
> max core performance. Here core performance will follow higher of the
> performance requests from each sibling.
>
> Reported-and-tested-by: Chen Yu <yu.c.chen@xxxxxxxxx>
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> ---
> drivers/cpufreq/intel_pstate.c | 28 ++++++++++++++++++++++++++--
> 1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 14f551a3d36e..501ab9f4489a 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -830,6 +830,28 @@ static void intel_pstate_hwp_set(unsigned int cpu)
> wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
> }
>
> +static void intel_pstate_hwp_force_min_perf(int cpu)
> +{
> + u64 value;
> + int min_perf;
> +
> + value = all_cpu_data[cpu]->hwp_req_cached;
> + value &= ~GENMASK_ULL(31, 0);
> + min_perf = HWP_LOWEST_PERF(all_cpu_data[cpu]->hwp_cap_cached);
> +
> + /* Set hwp_max = hwp_min */
> + value |= HWP_MAX_PERF(min_perf);
> + value |= HWP_MIN_PERF(min_perf);
> +
> + /* Set EPP/EPB to min */
> + if (static_cpu_has(X86_FEATURE_HWP_EPP))
> + value |= HWP_ENERGY_PERF_PREFERENCE(HWP_EPP_POWERSAVE);
> + else
> + intel_pstate_set_epb(cpu, HWP_EPP_BALANCE_POWERSAVE);
> +
> + wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
> +}
> +
> static int intel_pstate_hwp_save_state(struct cpufreq_policy *policy)
> {
> struct cpudata *cpu_data = all_cpu_data[policy->cpu];
> @@ -2093,10 +2115,12 @@ static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
> pr_debug("CPU %d exiting\n", policy->cpu);
>
> intel_pstate_clear_update_util_hook(policy->cpu);
> - if (hwp_active)
> + if (hwp_active) {
> intel_pstate_hwp_save_state(policy);
> - else
> + intel_pstate_hwp_force_min_perf(policy->cpu);
> + } else {
> intel_cpufreq_stop_cpu(policy);
> + }
> }
>
> static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
>
Both this one and the [2/2] applied, thanks!
