On Mon, Mar 05, 2018 at 02:10:59PM -0500, kan.li...@linux.intel.com wrote: SNIP
> diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c > index e3921ed..403c5e6 100644 > --- a/tools/perf/util/mmap.c > +++ b/tools/perf/util/mmap.c > @@ -235,16 +235,13 @@ static int overwrite_rb_find_range(void *buf, int mask, > u64 head, u64 *start, u6 > /* > * Report the start and end of the available data in ringbuffer > */ > -int perf_mmap__read_init(struct perf_mmap *md, bool overwrite, > - u64 *startp, u64 *endp) > +int perf_mmap__read_init(struct perf_mmap *md, bool overwrite) > { > u64 head = perf_mmap__read_head(md); > u64 old = md->prev; > unsigned char *data = md->base + page_size; > unsigned long size; > > - *startp = overwrite ? head : old; > - *endp = overwrite ? old : head; > md->overwrite = overwrite; hum, can't we set 'overwrite' at the moment we create struct perf_mmap? it's not changing during the mmap's lifetime.. maybe we could do it in perf_evlist__alloc_mmap function really nice cleanup! thanks, jirka