[PATCH] perf: ftrace: flush output after each writing

[Changbin Du]

The pager will result stdout in full buffering mode instead of line
buffering. We need to make the trace visible timely.

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxxx>
---
 tools/perf/builtin-ftrace.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 810e3376c7d6..ad2a9ae041f6 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -650,6 +650,8 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace)
 				break;
 			if (fwrite(buf, n, 1, stdout) != 1)
 				break;
+			/* flush output since stdout is in full buffering mode due to pager */
+			fflush(stdout);
 		}
 	}
 
-- 
2.25.1