Message ID | b4fcf3b4c2b5abcf79bbaf9780fe67b4ec697dee.1707363758.git.perry.yuan@amd.com (mailing list archive) |
---|---|
State | Superseded, archived |
Headers | show |
Series | AMD Pstate Fixes And Enhancements | expand |
On Thu, Feb 08, 2024 at 11:46:30AM +0800, Perry Yuan wrote: > Optimizes the process of retrieving the nominal frequency by utilizing > 'cpudata->nominal_freq' instead of repeatedly accessing the cppc_acpi interface. > > To enhance efficiency and reduce the CPU load, shifted to using > 'cpudata->nominal_freq'. It allows for the nominal frequency to be accessed > directly from the cached data in 'cpudata' of each CPU. > It will also slightly reduce the frequency change latency while using pstate > driver passive mode. > > Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > --- > drivers/cpufreq/amd-pstate.c | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index ac7faa98a450..ea8681ea3bad 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -619,7 +619,7 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata) > if (ret) > return ret; > > - nominal_freq = cppc_perf.nominal_freq; > + nominal_freq = READ_ONCE(cpudata->nominal_freq); Does it make sense to call cppc_get_perf_caps() in amd_pstate_cpu_init() and amd_pstate_epp_cpu_init() and cache all the relevant metrics such as highest_perf, lowest_perf, lowest_nonlinear_perf, nominal_perf, nominal_freq, lowest_freq so that subsequent calls to amd_get_max/min/lowest_nonlinear/nominal_freq() can use these cached values instead of calling cppc_get_perf_caps() again ? Because even with this patch, we continue to call cppc_get_perf_caps() in amd_get_max_freq(), amd_get_min_freq() and amd_get_lowest_nonlinear_freq(). > nominal_perf = READ_ONCE(cpudata->nominal_perf); > max_perf = READ_ONCE(cpudata->highest_perf); > > @@ -654,7 +654,7 @@ static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata) > if (ret) > return ret; > > - nominal_freq = cppc_perf.nominal_freq; > + nominal_freq = READ_ONCE(cpudata->nominal_freq); > nominal_perf = READ_ONCE(cpudata->nominal_perf); > > lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf; > @@ -848,13 +848,14 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy) > goto free_cpudata1; > > min_freq = amd_get_min_freq(cpudata); > - max_freq = amd_get_max_freq(cpudata); > nominal_freq = amd_get_nominal_freq(cpudata); > + cpudata->nominal_freq = nominal_freq; > + max_freq = amd_get_max_freq(cpudata); > lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); > > - if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { > - dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", > - min_freq, max_freq); > + if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) { +1 for the "nominal_freq == 0" check. On CPPCv2, nominal_freq and lowest_freq are not advertised. So nominal_freq will be 0. It is better to fail here than failing later at the time of governor initialization. > + dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) is incorrect\n", > + min_freq, max_freq, nominal_freq); > ret = -EINVAL; > goto free_cpudata1; > } > @@ -893,7 +894,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy) > cpudata->min_freq = min_freq; > cpudata->max_limit_freq = max_freq; > cpudata->min_limit_freq = min_freq; > - cpudata->nominal_freq = nominal_freq; > cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; > > policy->driver_data = cpudata; > @@ -1310,12 +1310,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) > goto free_cpudata1; > > min_freq = amd_get_min_freq(cpudata); > - max_freq = amd_get_max_freq(cpudata); > nominal_freq = amd_get_nominal_freq(cpudata); > + cpudata->nominal_freq = nominal_freq; > + max_freq = amd_get_max_freq(cpudata); > lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); > - if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { > - dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", > - min_freq, max_freq); > + if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) { Ditto. > + dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) is incorrect\n", > + min_freq, max_freq, nominal_freq); > ret = -EINVAL; > goto free_cpudata1; > } > @@ -1328,7 +1329,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) > /* Initial processor data capability frequencies */ > cpudata->max_freq = max_freq; > cpudata->min_freq = min_freq; > - cpudata->nominal_freq = nominal_freq; > cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; -- Thanks and Regards gautham.
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index ac7faa98a450..ea8681ea3bad 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -619,7 +619,7 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata) if (ret) return ret; - nominal_freq = cppc_perf.nominal_freq; + nominal_freq = READ_ONCE(cpudata->nominal_freq); nominal_perf = READ_ONCE(cpudata->nominal_perf); max_perf = READ_ONCE(cpudata->highest_perf); @@ -654,7 +654,7 @@ static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata) if (ret) return ret; - nominal_freq = cppc_perf.nominal_freq; + nominal_freq = READ_ONCE(cpudata->nominal_freq); nominal_perf = READ_ONCE(cpudata->nominal_perf); lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf; @@ -848,13 +848,14 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy) goto free_cpudata1; min_freq = amd_get_min_freq(cpudata); - max_freq = amd_get_max_freq(cpudata); nominal_freq = amd_get_nominal_freq(cpudata); + cpudata->nominal_freq = nominal_freq; + max_freq = amd_get_max_freq(cpudata); lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); - if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { - dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", - min_freq, max_freq); + if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) { + dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) is incorrect\n", + min_freq, max_freq, nominal_freq); ret = -EINVAL; goto free_cpudata1; } @@ -893,7 +894,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy) cpudata->min_freq = min_freq; cpudata->max_limit_freq = max_freq; cpudata->min_limit_freq = min_freq; - cpudata->nominal_freq = nominal_freq; cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; policy->driver_data = cpudata; @@ -1310,12 +1310,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) goto free_cpudata1; min_freq = amd_get_min_freq(cpudata); - max_freq = amd_get_max_freq(cpudata); nominal_freq = amd_get_nominal_freq(cpudata); + cpudata->nominal_freq = nominal_freq; + max_freq = amd_get_max_freq(cpudata); lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); - if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { - dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", - min_freq, max_freq); + if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) { + dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) is incorrect\n", + min_freq, max_freq, nominal_freq); ret = -EINVAL; goto free_cpudata1; } @@ -1328,7 +1329,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) /* Initial processor data capability frequencies */ cpudata->max_freq = max_freq; cpudata->min_freq = min_freq; - cpudata->nominal_freq = nominal_freq; cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; policy->driver_data = cpudata;