Re: [PATCH v3] perf script: Fix output type for dynamically allocated core PMU's

Liang, Kan
2024-12-16T15:38:49Z

On 2024-12-13 4:54 p.m., Thomas Falcon wrote:
> perf script output may show different fields on different core PMU's
> that exist on heterogeneous platforms. For example,
>
> perf record -e "{cpu_core/mem-loads-aux/,cpu_core/event=0xcd,\
> umask=0x01,ldlat=3,name=MEM_UOPS_RETIRED.LOAD_LATENCY/}:upp"\
> -c10000 -W -d -a -- sleep 1
>
> perf script:
>
> chromium-browse 46572 [002] 544966.882384: 10000 cpu_core/MEM_UOPS_RETIRED.LOAD_LATENCY/: 7ffdf1391b0c 10268100142 \
> |OP LOAD|LVL L1 hit|SNP None|TLB L1 or L2 hit|LCK No|BLK N/A 5 7 0 7fad7c47425d [unknown] (/usr/lib64/libglib-2.0.so.0.8000.3)
>
> perf record -e cpu_atom/event=0xd0,umask=0x05,ldlat=3,\
> name=MEM_UOPS_RETIRED.LOAD_LATENCY/upp -c10000 -W -d -a -- sleep 1
>
> perf script:
>
> gnome-control-c 534224 [023] 544951.816227: 10000 cpu_atom/MEM_UOPS_RETIRED.LOAD_LATENCY/: 7f0aaaa0aae0 [unknown] (/usr/lib64/libglib-2.0.so.0.8000.3)
>
> Some fields, such as data_src, are not included by default.
>
> The cause is that while one PMU may be assigned a type such as
> PERF_TYPE_RAW, other core PMU's are dynamically allocated at boot time.
> If this value does not match an existing PERF_TYPE_X value,
> output_type(perf_event_attr.type) will return OUTPUT_TYPE_OTHER.
>
> Instead search for a core PMU with a matching perf_event_attr type
> and, if one is found, return PERF_TYPE_RAW to match output of other
> core PMU's.
>
> Suggested-by: Kan Liang <kan.liang@intel.com>
> Signed-off-by: Thomas Falcon <thomas.falcon@intel.com>

Reviewed-by: Kan Liang <kan.liang@linux.intel.com>

Thanks,
Kan

> ---
> v2: restrict pmu lookup to platforms with more than one core pmu
> v3: only scan core pmu list
> ---
> tools/perf/builtin-script.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index 9e47905f75a6..685232883f9c 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -384,6 +384,19 @@ static int evsel_script__fprintf(struct evsel_script *es, FILE *fp)
> st.st_size / 1024.0 / 1024.0, es->filename, es->samples);
> }
>
> +static bool output_type_many_core_pmus(unsigned int type)
> +{
> + struct perf_pmu *pmu = NULL;
> +
> + if (perf_pmus__num_core_pmus() > 1) {
> + while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
> + if (pmu->type == type)
> + return true;
> + }
> + }
> + return false;
> +}
> +
> static inline int output_type(unsigned int type)
> {
> switch (type) {
> @@ -394,6 +407,9 @@ static inline int output_type(unsigned int type)
> return type;
> }
>
> + if (output_type_many_core_pmus(type))
> + return PERF_TYPE_RAW;