On Thu, Dec 21, 2017 at 10:08:50AM -0800, [email protected] wrote:
> From: Kan Liang <[email protected]>
>
> Per event overwrite term is not forbidden in perf top, which can bring
> problems. Because perf top only support non-overwrite mode.
>
> Check and forbid inconsistent per event overwrite term in the evlist.
> Make it possible to support either non-overwrite or overwrite mode.
> The overwrite mode is forbidden now, which will be removed when the
> overwrite mode is supported later.
>
> Signed-off-by: Kan Liang <[email protected]>
> ---
> tools/perf/builtin-top.c | 60
> ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 60 insertions(+)
>
> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> index c6ccda5..4b85e7b 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -881,6 +881,56 @@ static void perf_top__mmap_read(struct perf_top *top)
> perf_top__mmap_read_idx(top, i);
> }
>
> +/*
> + * Check per event overwrite term.
> + * perf top supports consistent mode for all events.
> + * Return -1 if the per event terms set but not consistent.
please list the rules for overwrite in the comment
are they just top specific?
SNIP
> + if (evsel == perf_evlist__first(evlist))
> + overwrite = set;
> + else
> + return -1;
> + }
> + }
> +
> + if ((overwrite >= 0) && (opts->overwrite != overwrite))
> + opts->overwrite = overwrite;
> +
> + return 0;
> +}
> +
> static int perf_top__start_counters(struct perf_top *top)
> {
> char msg[BUFSIZ];
> @@ -890,6 +940,16 @@ static int perf_top__start_counters(struct perf_top *top)
>
> perf_evlist__config(evlist, opts, &callchain_param);
so perf_evlist__config uses opts->overwrite, which you set
in your perf_top_overwrite_check call.. I'd think you need
to call it sooner
jirka
