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Date: Fri, 03 Mar 2017 23:51:31 +0100 From: "Rafael J. Wysocki" <rjw@...ysocki.net> To: Linux PM <linux-pm@...r.kernel.org> Cc: LKML <linux-kernel@...r.kernel.org>, Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com> Subject: [Update][PATCH v2 3/3] cpufreq: intel_pstate: Avoid triggering cpu_frequency tracepoint unnecessarily From: Rafael J. Wysocki <rafael.j.wysocki@...el.com> In the passive mode the cpu_frequency trace event is already triggered by the cpufreq core or by scaling governors, so intel_pstate should not trigger it once again for the same P-state updates. In addition to that, the frequency returned by intel_cpufreq_fast_switch() and passed via freqs.new from intel_cpufreq_target() to cpufreq_freq_transition_end() should reflect the P-state actually set, so make that happen. Fixes: 001c76f05b01 (cpufreq: intel_pstate: Generic governors support) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com> --- -> v2: As mentioned in the changelog, the frequencies propagated to the caller of intel_cpufreq_fast_switch() and to cpufreq_freq_transition_end() should reflect the P-state that was set and not the requested frequency (which may be different due to the global limits, rounding etc). --- drivers/cpufreq/intel_pstate.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -1879,13 +1879,11 @@ static int intel_pstate_prepare_request( intel_pstate_get_min_max(cpu, &min_perf, &max_perf); pstate = clamp_t(int, pstate, min_perf, max_perf); - trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu); return pstate; } static void intel_pstate_update_pstate(struct cpudata *cpu, int pstate) { - pstate = intel_pstate_prepare_request(cpu, pstate); if (pstate == cpu->pstate.current_pstate) return; @@ -1905,6 +1903,8 @@ static inline void intel_pstate_adjust_b update_turbo_state(); + target_pstate = intel_pstate_prepare_request(cpu, target_pstate); + trace_cpu_frequency(target_pstate * cpu->pstate.scaling, cpu->cpu); intel_pstate_update_pstate(cpu, target_pstate); sample = &cpu->sample; @@ -2365,6 +2365,7 @@ static int intel_cpufreq_target(struct c wrmsrl_on_cpu(policy->cpu, MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, target_pstate)); } + freqs.new = target_pstate * cpu->pstate.scaling; cpufreq_freq_transition_end(policy, &freqs, false); return 0; @@ -2378,8 +2379,9 @@ static unsigned int intel_cpufreq_fast_s target_freq = intel_cpufreq_turbo_update(cpu, policy, target_freq); target_pstate = DIV_ROUND_UP(target_freq, cpu->pstate.scaling); + target_pstate = intel_pstate_prepare_request(cpu, target_pstate); intel_pstate_update_pstate(cpu, target_pstate); - return target_freq; + return target_pstate * cpu->pstate.scaling; } static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy)
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