Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Fri, 4 Mar 2022 19:49:51 +0100 | Subject | Re: [PATCH V2 1/4] cpufreq: amd-pstate: Add more tracepoint for AMD P-State module |
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On Fri, Mar 4, 2022 at 7:42 AM Huang Rui <ray.huang@amd.com> wrote: > > On Fri, Mar 04, 2022 at 02:07:21PM +0800, Su, Jinzhou (Joe) wrote: > > Add frequency, mperf, aperf and tsc in the trace. This can be used > > to debug and tune the performance of AMD P-state driver. > > > > Use the time difference between amd_pstate_update to calculate CPU > > frequency. There could be sleep in arch_freq_get_on_cpu, so do not > > use it here. > > > > Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com> > > Co-developed-by: Huang Rui <ray.huang@amd.com> > > Signed-off-by: Huang Rui <ray.huang@amd.com> > > Let's remove "Signed-off-by" of me, just leave "Co-developed-by".
Actually, they both need to be present (the C-d-b clarifies the S-o-b meaning), so the above is correct.
> > > --- > > drivers/cpufreq/amd-pstate-trace.h | 22 ++++++++++- > > drivers/cpufreq/amd-pstate.c | 59 +++++++++++++++++++++++++++++- > > 2 files changed, 78 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/cpufreq/amd-pstate-trace.h b/drivers/cpufreq/amd-pstate-trace.h > > index 647505957d4f..35f38ae67fb1 100644 > > --- a/drivers/cpufreq/amd-pstate-trace.h > > +++ b/drivers/cpufreq/amd-pstate-trace.h > > @@ -27,6 +27,10 @@ TRACE_EVENT(amd_pstate_perf, > > TP_PROTO(unsigned long min_perf, > > unsigned long target_perf, > > unsigned long capacity, > > + u64 freq, > > + u64 mperf, > > + u64 aperf, > > + u64 tsc, > > unsigned int cpu_id, > > bool changed, > > bool fast_switch > > @@ -35,6 +39,10 @@ TRACE_EVENT(amd_pstate_perf, > > TP_ARGS(min_perf, > > target_perf, > > capacity, > > + freq, > > + mperf, > > + aperf, > > + tsc, > > cpu_id, > > changed, > > fast_switch > > @@ -44,6 +52,10 @@ TRACE_EVENT(amd_pstate_perf, > > __field(unsigned long, min_perf) > > __field(unsigned long, target_perf) > > __field(unsigned long, capacity) > > + __field(unsigned long long, freq) > > + __field(unsigned long long, mperf) > > + __field(unsigned long long, aperf) > > + __field(unsigned long long, tsc) > > __field(unsigned int, cpu_id) > > __field(bool, changed) > > __field(bool, fast_switch) > > @@ -53,15 +65,23 @@ TRACE_EVENT(amd_pstate_perf, > > __entry->min_perf = min_perf; > > __entry->target_perf = target_perf; > > __entry->capacity = capacity; > > + __entry->freq = freq; > > + __entry->mperf = mperf; > > + __entry->aperf = aperf; > > + __entry->tsc = tsc; > > __entry->cpu_id = cpu_id; > > __entry->changed = changed; > > __entry->fast_switch = fast_switch; > > ), > > > > - TP_printk("amd_min_perf=%lu amd_des_perf=%lu amd_max_perf=%lu cpu_id=%u changed=%s fast_switch=%s", > > + TP_printk("amd_min_perf=%lu amd_des_perf=%lu amd_max_perf=%lu freq=%llu mperf=%llu aperf=%llu tsc=%llu cpu_id=%u changed=%s fast_switch=%s", > > (unsigned long)__entry->min_perf, > > (unsigned long)__entry->target_perf, > > (unsigned long)__entry->capacity, > > + (unsigned long long)__entry->freq, > > + (unsigned long long)__entry->mperf, > > + (unsigned long long)__entry->aperf, > > + (unsigned long long)__entry->tsc, > > (unsigned int)__entry->cpu_id, > > (__entry->changed) ? "true" : "false", > > (__entry->fast_switch) ? "true" : "false" > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > > index 9ce75ed11f8e..7be38bc6a673 100644 > > --- a/drivers/cpufreq/amd-pstate.c > > +++ b/drivers/cpufreq/amd-pstate.c > > @@ -65,6 +65,18 @@ MODULE_PARM_DESC(shared_mem, > > > > static struct cpufreq_driver amd_pstate_driver; > > > > +/** > > + * struct amd_aperf_mperf > > + * @aperf: actual performance frequency clock count > > + * @mperf: maximum performance frequency clock count > > + * @tsc: time stamp counter > > + */ > > +struct amd_aperf_mperf { > > + u64 aperf; > > + u64 mperf; > > + u64 tsc; > > +}; > > + > > /** > > * struct amd_cpudata - private CPU data for AMD P-State > > * @cpu: CPU number > > @@ -81,6 +93,9 @@ static struct cpufreq_driver amd_pstate_driver; > > * @min_freq: the frequency that mapped to lowest_perf > > * @nominal_freq: the frequency that mapped to nominal_perf > > * @lowest_nonlinear_freq: the frequency that mapped to lowest_nonlinear_perf > > + * @cur: Difference of Aperf/Mperf/tsc count between last and current sample > > + * @prev: Last Aperf/Mperf/tsc count value read from register > > + * @freq: current cpu frequency value > > * @boost_supported: check whether the Processor or SBIOS supports boost mode > > * > > * The amd_cpudata is key private data for each CPU thread in AMD P-State, and > > @@ -102,6 +117,10 @@ struct amd_cpudata { > > u32 nominal_freq; > > u32 lowest_nonlinear_freq; > > > > + struct amd_aperf_mperf cur; > > + struct amd_aperf_mperf prev; > > + > > + u64 freq; > > bool boost_supported; > > }; > > > > @@ -211,6 +230,39 @@ static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata, > > max_perf, fast_switch); > > } > > > > +static inline bool amd_pstate_sample(struct amd_cpudata *cpudata) > > +{ > > + u64 aperf, mperf, tsc; > > + unsigned long flags; > > + > > + local_irq_save(flags); > > + rdmsrl(MSR_IA32_APERF, aperf); > > + rdmsrl(MSR_IA32_MPERF, mperf); > > + tsc = rdtsc(); > > + > > + if (cpudata->prev.mperf == mperf || cpudata->prev.tsc == tsc) { > > + local_irq_restore(flags); > > + return false; > > + } > > + > > + local_irq_restore(flags); > > + > > + cpudata->cur.aperf = aperf; > > + cpudata->cur.mperf = mperf; > > + cpudata->cur.tsc = tsc; > > + cpudata->cur.aperf -= cpudata->prev.aperf; > > + cpudata->cur.mperf -= cpudata->prev.mperf; > > + cpudata->cur.tsc -= cpudata->prev.tsc; > > + > > + cpudata->prev.aperf = aperf; > > + cpudata->prev.mperf = mperf; > > + cpudata->prev.tsc = tsc; > > + > > + cpudata->freq = div64_u64((cpudata->cur.aperf * cpu_khz), cpudata->cur.mperf); > > + > > + return true; > > +} > > + > > static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf, > > u32 des_perf, u32 max_perf, bool fast_switch) > > { > > @@ -226,8 +278,11 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf, > > value &= ~AMD_CPPC_MAX_PERF(~0L); > > value |= AMD_CPPC_MAX_PERF(max_perf); > > > > - trace_amd_pstate_perf(min_perf, des_perf, max_perf, > > - cpudata->cpu, (value != prev), fast_switch); > > + if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) { > > + trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq, > > + cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc, > > + cpudata->cpu, (value != prev), fast_switch); > > How about using struct amd_aperf_mperf pointer as one input: > > trace_amd_pstate_perf(min_perf, des_perf, max_perf, &cpudata->cur, ...); > > You can refer the members of struct amd_aperf_mperf in the > amd-pstate-trace.h: > > __entry->mperf = cur->mperf; > __entry->aperf = cur->aperf; > __entry->tsc = cur->tsc; > > Thanks, > Ray
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