perf top: Start display thread earlier

If events are coming in at a rate such that the event processing thread
can barely keep up, our initial run of the event ring will almost never
terminate and this delays the starting of the display thread.

The screen basically stays black until the event thread can get out of
it's endless loop.

Therefore, start the display thread before we start processing the ring
buffer.

This also make sure that we always have the user requested real time
setting engaged when processing the ring.

Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20181030.223003.2242527041807905962.davem@davemloft.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
David Miller 2018-10-30 22:30:03 -07:00 committed by Arnaldo Carvalho de Melo
parent 76b0b80178
commit ff27a06af6

View file

@ -1134,11 +1134,6 @@ static int __cmd_top(struct perf_top *top)
if (!target__none(&opts->target))
perf_evlist__enable(top->evlist);
/* Wait for a minimal set of events before starting the snapshot */
perf_evlist__poll(top->evlist, 100);
perf_top__mmap_read(top);
ret = -1;
if (pthread_create(&thread, NULL, (use_browser > 0 ? display_thread_tui :
display_thread), top)) {
@ -1156,6 +1151,11 @@ static int __cmd_top(struct perf_top *top)
}
}
/* Wait for a minimal set of events before starting the snapshot */
perf_evlist__poll(top->evlist, 100);
perf_top__mmap_read(top);
while (!done) {
u64 hits = top->samples;