[PATCH 2/2] perf evlist: Support pipe mode display
From: Namhyung Kim
Date: Thu Dec 10 2020 - 01:14:29 EST
Likewise, perf evlist command should print event attributes by reading
PERF_RECORD_HEADER_ATTR records.
Before:
$ perf record -o- true | ./perf evlist -i-
(prints nothing)
After:
$ perf record -o- true | ./perf evlist -i-
cycles:pppH
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-evlist.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/tools/perf/builtin-evlist.c b/tools/perf/builtin-evlist.c
index 98e992801251..4617b32c9c97 100644
--- a/tools/perf/builtin-evlist.c
+++ b/tools/perf/builtin-evlist.c
@@ -17,6 +17,14 @@
#include "util/data.h"
#include "util/debug.h"
#include <linux/err.h>
+#include "util/tool.h"
+
+static int process_header_feature(struct perf_session *session __maybe_unused,
+ union perf_event *event __maybe_unused)
+{
+ session_done = 1;
+ return 0;
+}
static int __cmd_evlist(const char *file_name, struct perf_attr_details *details)
{
@@ -27,12 +35,20 @@ static int __cmd_evlist(const char *file_name, struct perf_attr_details *details
.mode = PERF_DATA_MODE_READ,
.force = details->force,
};
+ struct perf_tool tool = {
+ /* only needed for pipe mode */
+ .attr = perf_event__process_attr,
+ .feature = process_header_feature,
+ };
bool has_tracepoint = false;
- session = perf_session__new(&data, 0, NULL);
+ session = perf_session__new(&data, 0, &tool);
if (IS_ERR(session))
return PTR_ERR(session);
+ if (data.is_pipe)
+ perf_session__process_events(session);
+
evlist__for_each_entry(session->evlist, pos) {
evsel__fprintf(pos, details, stdout);
--
2.29.2.576.ga3fc446d84-goog