[tip:perf/urgent] perf top: Fix annoying fallback message on older kernels

From: tip-bot for Kan Liang
Date: Wed Mar 07 2018 - 03:25:33 EST


Commit-ID: 626af862da9c650e80bdea44684be9334f8eb75b
Gitweb: https://git.kernel.org/tip/626af862da9c650e80bdea44684be9334f8eb75b
Author: Kan Liang <Kan.liang@xxxxxxxxx>
AuthorDate: Mon, 26 Feb 2018 10:17:10 -0800
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 5 Mar 2018 11:48:56 -0300

perf top: Fix annoying fallback message on older kernels

On older (e.g. v4.4) kernels, an annoying fallback message can be
observed in 'perf top':

ââWarning:âââââââââââââââââââââââ
âfall back to non-overwrite modeâ
â â
â â
âPress any key... â
âââââââââââââââââââââââââââââââââ

The 'perf top' utility has been changed to overwrite mode since commit
ebebbf082357 ("perf top: Switch default mode to overwrite mode").

For older kernels which don't have overwrite mode support, 'perf top'
will fall back to non-overwrite mode and print out the fallback message
using ui__warning(), which needs user's input to close.

The fallback message is not critical for end users. Turning it to debug
message which is printed when running with -vv.

Reported-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxx>
Fixes: ebebbf082357 ("perf top: Switch default mode to overwrite mode")
Link: http://lkml.kernel.org/r/1519669030-176549-1-git-send-email-kan.liang@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-top.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index b7c823ba8374..35ac016fcb98 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -991,7 +991,7 @@ static int perf_top_overwrite_fallback(struct perf_top *top,
evlist__for_each_entry(evlist, counter)
counter->attr.write_backward = false;
opts->overwrite = false;
- ui__warning("fall back to non-overwrite mode\n");
+ pr_debug2("fall back to non-overwrite mode\n");
return 1;
}