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Commit a923e2c4 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
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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: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarPekka 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent b1019d5e

tools/perf/builtin-kmem.c

+14 −3
Original line number Diff line number Diff line
@@ -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[] = "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 @@ 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;

		}