[tip:perf/core] perf top: Do show usage message when failing to create cpu/thread maps

[tip:perf/core] perf top: Do show usage message when failing to create cpu/thread maps

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  f8a5c0b24b8b1e77a0812b0c8251db0afc0524b7
Gitweb:     http://git.kernel.org/tip/f8a5c0b24b8b1e77a0812b0c8251db0afc0524b7
Author:     Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Thu, 10 Dec 2015 14:48:45 -0300
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 10 Dec 2015 15:47:47 -0300

perf top: Do show usage message when failing to create cpu/thread maps

This is necessary to get rid of the browser dependency from
usage_with_options() and its friends.  Because we validate the targets
which are used to create the cpu/thread maps and inform the user about
any override performed via the chosen UI, we don't need to call the
usage routine for that.

Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-slu7lj7buzpwgop1vo9la8ma@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-top.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 7e2e72e..84fd636 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1279,8 +1279,11 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (target__none(target))
 		target->system_wide = true;
 
-	if (perf_evlist__create_maps(top.evlist, target) < 0)
-		usage_with_options(top_usage, options);
+	if (perf_evlist__create_maps(top.evlist, target) < 0) {
+		ui__error("Couldn't create thread/CPU maps: %s\n",
+			  errno == ENOENT ? "No such process" : strerror_r(errno, errbuf, sizeof(errbuf)));
+		goto out_delete_evlist;
+	}
 
 	if (!top.evlist->nr_entries &&
 	    perf_evlist__add_default(top.evlist) < 0) {