[PATCH 04/28] perf top: Fix annoying fallback message on older kernels

Arnaldo Carvalho de Melo
2018-03-05T14:29:57Z

From: Kan Liang <Kan.liang@intel.com>

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

┌─Warning:──────────────────────┐
│fall back to non-overwrite mode│
│ │
│ │
│Press any key... │
└───────────────────────────────┘

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@kernel.org>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Fixes: ebebbf082357 ("perf top: Switch default mode to overwrite mode")
Link: http://lkml.kernel.org/r/1519669030-176549-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
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;
}

--
2.14.3