On Mon, Sep 25, 2017 at 01:23:08PM -0700, kan.li...@intel.com wrote:
> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> index 6a0d7ff..ef0b6b1 100644
> --- a/tools/perf/util/evlist.c
> +++ b/tools/perf/util/evlist.c
> @@ -723,7 +723,10 @@ perf_mmap__read(struct perf_mmap *md, bool check_messup,
> u64 start,
> * In either case, truncate and restart at 'end'.
> */
> if (diff > md->mask / 2 || diff < 0) {
> - fprintf(stderr, "WARNING: failed to keep up with mmap
> data.\n");
> + WARN_ONCE(1, "WARNING: failed to keep up with mmap
> data.\n"
> + "Please try increasing the period (-c)
> or\n"
> + "decreasing the freq (-F) or\n"
> + "limiting the number of CPUs");
should suggest -C too
"limiting the number of CPUs (-C)");
-Andi
