perf kmem: Show warning when trying to run stat without record
Sometimes one can mistakenly run 'perf kmem stat' without running 'perf
kmem record' before or with a different configuration like recording
--slab and stat --page. Show a warning message like the one below to
inform the user:
# perf kmem stat --page --caller
No page allocation events found. Have you run 'perf kmem record --page'?
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1430837572-31395-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 828b728..e628bf1 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -1882,6 +1882,7 @@
};
struct perf_session *session;
int ret = -1;
+ const char errmsg[] = "No %s allocation events found. Have you run 'perf kmem record --%s'?\n";
perf_config(kmem_config, NULL);
argc = parse_options_subcommand(argc, argv, kmem_options,
@@ -1908,11 +1909,21 @@
if (session == NULL)
return -1;
- if (kmem_page) {
- struct perf_evsel *evsel = perf_evlist__first(session->evlist);
+ if (kmem_slab) {
+ if (!perf_evlist__find_tracepoint_by_name(session->evlist,
+ "kmem:kmalloc")) {
+ pr_err(errmsg, "slab", "slab");
+ return -1;
+ }
+ }
- if (evsel == NULL || evsel->tp_format == NULL) {
- pr_err("invalid event found.. aborting\n");
+ if (kmem_page) {
+ struct perf_evsel *evsel;
+
+ evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
+ "kmem:mm_page_alloc");
+ if (evsel == NULL) {
+ pr_err(errmsg, "page", "page");
return -1;
}