Re: [PATCH v2 13/17] cpufreq/amd-pstate: Move all EPP tracing into *_update_perf and *_set_epp functions

Gautham R. Shenoy
2025-02-17T14:14:30Z

On Fri, Feb 14, 2025 at 06:52:40PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
>
> The EPP tracing is done by the caller today, but this precludes the
> information about whether the CPPC request has changed.
>
> Move it into the update_perf and set_epp functions and include information
> about whether the request has changed from the last one.

A consequential change is that the amd_pstate_update_perf() and the
amd_pstate_set_epp() functions now have the cpufreq_policy parameter
in place of the cpudata parameter as policy->boost_enabled is needed
by the tracepoint. Can you please add this to the commit log?

Otherwise, the patch looks good to me.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

--
Thanks and Regards
gautham.

>
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> drivers/cpufreq/amd-pstate-trace.h | 13 +++-
> drivers/cpufreq/amd-pstate.c | 119 +++++++++++++++++------------
> 2 files changed, 81 insertions(+), 51 deletions(-)
>
> diff --git a/drivers/cpufreq/amd-pstate-trace.h b/drivers/cpufreq/amd-pstate-trace.h
> index f457d4af2c62e..32e1bdc588c52 100644
> --- a/drivers/cpufreq/amd-pstate-trace.h
> +++ b/drivers/cpufreq/amd-pstate-trace.h
> @@ -90,7 +90,8 @@ TRACE_EVENT(amd_pstate_epp_perf,
> u8 epp,
> u8 min_perf,
> u8 max_perf,
> - bool boost
> + bool boost,
> + bool changed
> ),
>
> TP_ARGS(cpu_id,
> @@ -98,7 +99,8 @@ TRACE_EVENT(amd_pstate_epp_perf,
> epp,
> min_perf,
> max_perf,
> - boost),
> + boost,
> + changed),
>
> TP_STRUCT__entry(
> __field(unsigned int, cpu_id)
> @@ -107,6 +109,7 @@ TRACE_EVENT(amd_pstate_epp_perf,
> __field(u8, min_perf)
> __field(u8, max_perf)
> __field(bool, boost)
> + __field(bool, changed)
> ),
>
> TP_fast_assign(
> @@ -116,15 +119,17 @@ TRACE_EVENT(amd_pstate_epp_perf,
> __entry->min_perf = min_perf;
> __entry->max_perf = max_perf;
> __entry->boost = boost;
> + __entry->changed = changed;
> ),
>
> - TP_printk("cpu%u: [%hhu<->%hhu]/%hhu, epp=%hhu, boost=%u",
> + TP_printk("cpu%u: [%hhu<->%hhu]/%hhu, epp=%hhu, boost=%u, changed=%u",
> (unsigned int)__entry->cpu_id,
> (u8)__entry->min_perf,
> (u8)__entry->max_perf,
> (u8)__entry->highest_perf,
> (u8)__entry->epp,
> - (bool)__entry->boost
> + (bool)__entry->boost,
> + (bool)__entry->changed
> )
> );
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 9517da9b7e692..1304bdc23e809 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -228,9 +228,10 @@ static u8 shmem_get_epp(struct amd_cpudata *cpudata)
> return FIELD_GET(AMD_CPPC_EPP_PERF_MASK, epp);
> }
>
> -static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
> +static int msr_update_perf(struct cpufreq_policy *policy, u8 min_perf,
> u8 des_perf, u8 max_perf, u8 epp, bool fast_switch)
> {
> + struct amd_cpudata *cpudata = policy->driver_data;
> u64 value, prev;
>
> value = prev = READ_ONCE(cpudata->cppc_req_cached);
> @@ -242,6 +243,18 @@ static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
> value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
> value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
>
> + if (trace_amd_pstate_epp_perf_enabled()) {
> + union perf_cached perf = READ_ONCE(cpudata->perf);
> +
> + trace_amd_pstate_epp_perf(cpudata->cpu,
> + perf.highest_perf,
> + epp,
> + min_perf,
> + max_perf,
> + policy->boost_enabled,
> + value != prev);
> + }
> +
> if (value == prev)
> return 0;
>
> @@ -256,24 +269,26 @@ static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
> }
>
> WRITE_ONCE(cpudata->cppc_req_cached, value);
> - WRITE_ONCE(cpudata->epp_cached, epp);
> + if (epp != cpudata->epp_cached)
> + WRITE_ONCE(cpudata->epp_cached, epp);
>
> return 0;
> }
>
> DEFINE_STATIC_CALL(amd_pstate_update_perf, msr_update_perf);
>
> -static inline int amd_pstate_update_perf(struct amd_cpudata *cpudata,
> +static inline int amd_pstate_update_perf(struct cpufreq_policy *policy,
> u8 min_perf, u8 des_perf,
> u8 max_perf, u8 epp,
> bool fast_switch)
> {
> - return static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
> + return static_call(amd_pstate_update_perf)(policy, min_perf, des_perf,
> max_perf, epp, fast_switch);
> }
>
> -static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
> +static int msr_set_epp(struct cpufreq_policy *policy, u8 epp)
> {
> + struct amd_cpudata *cpudata = policy->driver_data;
> u64 value, prev;
> int ret;
>
> @@ -281,6 +296,19 @@ static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
> value &= ~AMD_CPPC_EPP_PERF_MASK;
> value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
>
> + if (trace_amd_pstate_epp_perf_enabled()) {
> + union perf_cached perf = cpudata->perf;
> +
> + trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> + epp,
> + FIELD_GET(AMD_CPPC_MIN_PERF_MASK,
> + cpudata->cppc_req_cached),
> + FIELD_GET(AMD_CPPC_MAX_PERF_MASK,
> + cpudata->cppc_req_cached),
> + policy->boost_enabled,
> + value != prev);
> + }
> +
> if (value == prev)
> return 0;
>
> @@ -299,15 +327,29 @@ static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
>
> DEFINE_STATIC_CALL(amd_pstate_set_epp, msr_set_epp);
>
> -static inline int amd_pstate_set_epp(struct amd_cpudata *cpudata, u8 epp)
> +static inline int amd_pstate_set_epp(struct cpufreq_policy *policy, u8 epp)
> {
> - return static_call(amd_pstate_set_epp)(cpudata, epp);
> + return static_call(amd_pstate_set_epp)(policy, epp);
> }
>
> -static int shmem_set_epp(struct amd_cpudata *cpudata, u8 epp)
> +static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
> {
> - int ret;
> + struct amd_cpudata *cpudata = policy->driver_data;
> struct cppc_perf_ctrls perf_ctrls;
> + int ret;
> +
> + if (trace_amd_pstate_epp_perf_enabled()) {
> + union perf_cached perf = cpudata->perf;
> +
> + trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> + epp,
> + FIELD_GET(AMD_CPPC_MIN_PERF_MASK,
> + cpudata->cppc_req_cached),
> + FIELD_GET(AMD_CPPC_MAX_PERF_MASK,
> + cpudata->cppc_req_cached),
> + policy->boost_enabled,
> + epp != cpudata->epp_cached);
> + }
>
> if (epp == cpudata->epp_cached)
> return 0;
> @@ -339,17 +381,7 @@ static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
> return -EBUSY;
> }
>
> - if (trace_amd_pstate_epp_perf_enabled()) {
> - union perf_cached perf = READ_ONCE(cpudata->perf);
> -
> - trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> - epp,
> - FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
> - FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
> - policy->boost_enabled);
> - }
> -
> - return amd_pstate_set_epp(cpudata, epp);
> + return amd_pstate_set_epp(policy, epp);
> }
>
> static inline int msr_cppc_enable(bool enable)
> @@ -492,15 +524,16 @@ static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata)
> return static_call(amd_pstate_init_perf)(cpudata);
> }
>
> -static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
> +static int shmem_update_perf(struct cpufreq_policy *policy, u8 min_perf,
> u8 des_perf, u8 max_perf, u8 epp, bool fast_switch)
> {
> + struct amd_cpudata *cpudata = policy->driver_data;
> struct cppc_perf_ctrls perf_ctrls;
> u64 value, prev;
> int ret;
>
> if (cppc_state == AMD_PSTATE_ACTIVE) {
> - int ret = shmem_set_epp(cpudata, epp);
> + int ret = shmem_set_epp(policy, epp);
>
> if (ret)
> return ret;
> @@ -515,6 +548,18 @@ static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
> value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
> value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
>
> + if (trace_amd_pstate_epp_perf_enabled()) {
> + union perf_cached perf = READ_ONCE(cpudata->perf);
> +
> + trace_amd_pstate_epp_perf(cpudata->cpu,
> + perf.highest_perf,
> + epp,
> + min_perf,
> + max_perf,
> + policy->boost_enabled,
> + value != prev);
> + }
> +
> if (value == prev)
> return 0;
>
> @@ -592,7 +637,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
> cpudata->cpu, fast_switch);
> }
>
> - amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
> + amd_pstate_update_perf(policy, min_perf, des_perf, max_perf, 0, fast_switch);
> }
>
> static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
> @@ -1527,7 +1572,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
> return ret;
> WRITE_ONCE(cpudata->cppc_req_cached, value);
> }
> - ret = amd_pstate_set_epp(cpudata, cpudata->epp_default);
> + ret = amd_pstate_set_epp(policy, cpudata->epp_default);
> if (ret)
> return ret;
>
> @@ -1568,14 +1613,8 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
> epp = READ_ONCE(cpudata->epp_cached);
>
> perf = READ_ONCE(cpudata->perf);
> - if (trace_amd_pstate_epp_perf_enabled()) {
> - trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf, epp,
> - perf.min_limit_perf,
> - perf.max_limit_perf,
> - policy->boost_enabled);
> - }
>
> - return amd_pstate_update_perf(cpudata, perf.min_limit_perf, 0U,
> + return amd_pstate_update_perf(policy, perf.min_limit_perf, 0U,
> perf.max_limit_perf, epp, false);
> }
>
> @@ -1615,14 +1654,7 @@ static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
> if (ret)
> pr_err("failed to enable amd pstate during resume, return %d\n", ret);
>
> - if (trace_amd_pstate_epp_perf_enabled()) {
> - trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> - cpudata->epp_cached,
> - FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
> - perf.highest_perf, policy->boost_enabled);
> - }
> -
> - return amd_pstate_update_perf(cpudata, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
> + return amd_pstate_update_perf(policy, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
> }
>
> static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
> @@ -1648,14 +1680,7 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
> if (cpudata->suspended)
> return 0;
>
> - if (trace_amd_pstate_epp_perf_enabled()) {
> - trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> - AMD_CPPC_EPP_BALANCE_POWERSAVE,
> - perf.lowest_perf, perf.lowest_perf,
> - policy->boost_enabled);
> - }
> -
> - return amd_pstate_update_perf(cpudata, perf.lowest_perf, 0, perf.lowest_perf,
> + return amd_pstate_update_perf(policy, perf.lowest_perf, 0, perf.lowest_perf,
> AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
> }
>
> --
> 2.43.0
>