[PATCH 13/19] perf ftrace: Use pager for displaying result

[Namhyung Kim <namhyung@kernel.org>]

From: Namhyung Kim <namhyung.kim@lge.com>

It's convenient to use pager when seeing many lines of result.

Note that setup_pager() should be called after perf_evlist__
prepare_workload() since they can interfere each other regarding
shared stdio streams.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 1e28dc7e9743..8bb2604517cc 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -227,6 +227,7 @@ static int do_ftrace_live(struct perf_ftrace *ftrace)
 	signal(SIGINT, sig_handler);
 	signal(SIGUSR1, sig_handler);
 	signal(SIGCHLD, sig_handler);
+	signal(SIGPIPE, sig_handler);
 
 	if (setup_tracing_files(ftrace) < 0)
 		goto out_reset;
@@ -1415,6 +1416,8 @@ __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 						  argv, false, true) < 0)
 		goto out_maps;
 
+	setup_pager();
+
 	ret = do_ftrace_live(ftrace);
 
 out_maps:
@@ -1536,6 +1539,8 @@ __cmd_ftrace_show(struct perf_ftrace *ftrace, int argc, const char **argv)
 	if (ftrace->dirname == NULL)
 		ftrace->dirname = DEFAULT_DIRNAME;
 
+	setup_pager();
+
 	ret = do_ftrace_show(ftrace);
 
 	perf_evlist__delete_maps(ftrace->evlist);
@@ -1597,6 +1602,7 @@ __cmd_ftrace_report(struct perf_ftrace *ftrace, int argc, const char **argv)
 	perf_hpp__column_enable(PERF_HPP__OVERHEAD);
 	perf_hpp__init();
 
+	setup_pager();
 	setup_sorting();
 
 	symbol_conf.exclude_other = false;
-- 
1.7.11.7