Re: [PATCH perf/urgent] perf top: Always sample time
- Date: Mon, 15 Apr 2019 14:22:15 -0300
- From: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>
- Subject: Re: [PATCH perf/urgent] perf top: Always sample time
Em Mon, Apr 15, 2019 at 02:53:33PM +0200, Jiri Olsa escreveu:
> Bastian reported broken perf top -p PID command, it won't
> display any data.
> The problem is that for -p option we monitor single thread,
> so we don't enable time in samples, because it's not needed.
> However since commit 16c66bc167cc we use ordered queues to
> stash data plus later commits added logic for dropping samples
> in case there's big load and we don't keep up. All this needs
> timestamp for sample. Enabling it unconditionally for perf top.
Thanks, tested and applied.
> Fixes: 16c66bc167cc ("perf top: Add processing thread")
> Reported-by: Bastian Beischer <bastian.beischer@xxxxxxxxxxxxxx>
> Link: http://lkml.kernel.org/n/tip-zhn7jg8hqpl9547g7vqjini7@xxxxxxxxxxxxxx
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> tools/perf/builtin-top.c | 1 +
> 1 file changed, 1 insertion(+)
> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> index 1999d6533d12..fbbb0da43abb 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -1377,6 +1377,7 @@ int cmd_top(int argc, const char **argv)
> * */
> .overwrite = 0,
> .sample_time = true,
> + .sample_time_set = true,
> .max_stack = sysctl__max_stack(),
> .annotation_opts = annotation__default_options,