Re: [PATCH v5 4/8] perf record: Introduce rec->overwrite_evlist for overwritable events

From: Wangnan (F)
Date: Wed May 25 2016 - 06:18:18 EST

On 2016/5/25 13:03, Wang Nan wrote:
Create an auxiliary evlist for overwritable events.

Before mmap, build this evlist and set 'overwrite' and 'backward'
attribute. Since perf_evlist__mmap_ex() only maps events when
evsel->overwrite matches evlist's corresponding attributes, with
these two evlists an event goes to either rec->evlist or

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
tools/perf/builtin-record.c | 138 ++++++++++++++++++++++++++++++++++++--------
1 file changed, 114 insertions(+), 24 deletions(-)


@@ -941,7 +1026,10 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
err = 0;
- if (perf_evlist__filter_pollfd(rec->evlist, POLLERR | POLLHUP) == 0)
+ active_evts = perf_evlist__filter_pollfd(rec->evlist, POLLERR | POLLHUP);
+ active_evts += perf_evlist__filter_pollfd(rec->overwrite_evlist, POLLERR | POLLHUP);

Sorry, before calling filter here should check if rec->overwrite_evlist is not NULL.
I'll resend this patch with this problem fixed soon.