Sometimes one can mistakenly run perf kmem stat without perf kmem
record before or different configuration like recoding --slab and stat
--page. Show a warning message like below to inform user:
# perf kmem stat --page --caller
Not found page events. Have you run 'perf kmem record --page' before?
Acked-by: Pekka Enberg <penberg@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
Use perf_evlist__find_tracepoint_by_name().
tools/perf/builtin-kmem.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 828b7284e547..5868b4347925 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -1882,6 +1882,7 @@ int cmd_kmem(int argc, const char **argv, const char *prefix __maybe_unused)
};
struct perf_session *session;
int ret = -1;
+ const char errmsg[] = "Not found %s events. Have you run 'perf kmem record --%s' before?\n";
perf_config(kmem_config, NULL);
argc = parse_options_subcommand(argc, argv, kmem_options,
@@ -1908,11 +1909,21 @@ int cmd_kmem(int argc, const char **argv, const char *prefix __maybe_unused)
if (session == NULL)
return -1;
+ if (kmem_slab) {
+ if (!perf_evlist__find_tracepoint_by_name(session->evlist,
+ "kmem:kmalloc")) {
+ pr_err(errmsg, "slab", "slab");
+ return -1;
+ }
+ }
+
if (kmem_page) {
- struct perf_evsel *evsel = perf_evlist__first(session->evlist);
+ struct perf_evsel *evsel;
- if (evsel == NULL || evsel->tp_format == NULL) {
- pr_err("invalid event found.. aborting\n");
+ evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
+ "kmem:mm_page_alloc");
+ if (evsel == NULL) {
+ pr_err(errmsg, "page", "page");
return -1;
}
--
2.3.7
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