[PATCH v2 3/3] perf list: Support filtering in JSON output

From: Namhyung Kim

Date: Wed Nov 19 2025 - 19:47:30 EST


Like regular output mode, it should honor command line arguments to
limit to a certain type of PMUs or events.

$ perf list -j hw
[
{
"Unit": "cpu",
"Topic": "legacy hardware",
"EventName": "branch-instructions",
"EventType": "Kernel PMU event",
"BriefDescription": "Retired branch instructions [This event is an alias of branches]",
"Encoding": "cpu/event=0xc4\n/"
},
{
"Unit": "cpu",
"Topic": "legacy hardware",
"EventName": "branch-misses",
"EventType": "Kernel PMU event",
"BriefDescription": "Mispredicted branch instructions",
"Encoding": "cpu/event=0xc5\n/"
},
...

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-list.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
index 6c5913f129f39c94..5cbca0bacd35237e 100644
--- a/tools/perf/builtin-list.c
+++ b/tools/perf/builtin-list.c
@@ -373,6 +373,23 @@ static void json_print_event(void *ps, const char *topic,
FILE *fp = print_state->common.fp;
struct strbuf buf;

+ if (deprecated && !print_state->common.deprecated)
+ return;
+
+ if (print_state->common.pmu_glob &&
+ (!pmu_name || !strglobmatch(pmu_name, print_state->common.pmu_glob)))
+ return;
+
+ if (print_state->common.exclude_abi && pmu_type < PERF_TYPE_MAX &&
+ pmu_type != PERF_TYPE_RAW)
+ return;
+
+ if (print_state->common.event_glob &&
+ (!event_name || !strglobmatch(event_name, print_state->common.event_glob)) &&
+ (!event_alias || !strglobmatch(event_alias, print_state->common.event_glob)) &&
+ (!topic || !strglobmatch_nocase(topic, print_state->common.event_glob)))
+ return;
+
strbuf_init(&buf, 0);
fprintf(fp, "%s{\n", print_state->need_sep ? ",\n" : "");
print_state->need_sep = true;
@@ -449,6 +466,13 @@ static void json_print_metric(void *ps __maybe_unused, const char *group,
FILE *fp = print_state->common.fp;
struct strbuf buf;

+ if (print_state->common.event_glob &&
+ (!print_state->common.metrics || !name ||
+ !strglobmatch(name, print_state->common.event_glob)) &&
+ (!print_state->common.metricgroups || !group ||
+ !strglobmatch(group, print_state->common.event_glob)))
+ return;
+
strbuf_init(&buf, 0);
fprintf(fp, "%s{\n", print_state->need_sep ? ",\n" : "");
print_state->need_sep = true;
--
2.52.0.rc1.455.g30608eb744-goog