From ff27a06af6ffd3f49b9e193eb68f487ad76651e1 Mon Sep 17 00:00:00 2001 From: David Miller Date: Tue, 30 Oct 2018 22:30:03 -0700 Subject: [PATCH] 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 Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Link: http://lkml.kernel.org/r/20181030.223003.2242527041807905962.davem@davemloft.net Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-top.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 8e29e0cc8626..b2838de13de0 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -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;