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

From: Thomas Falcon
Date: Fri Dec 13 2024 - 16:55:40 EST


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@xxxxxxxxx>
Signed-off-by: Thomas Falcon <thomas.falcon@xxxxxxxxx>
---
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;
+
return OUTPUT_TYPE_OTHER;
}

--
2.47.1