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
ebebbf0823 ("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: ebebbf0823 ("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>
626af862da