[PATCH 08/12] perf tools: Fix side band thread draining

[Jiri Olsa]

Current perf_evlist__poll_thread code could finish
without draining the data. Adding the logic that
makes sure we won't finish before the drain.

Fixes: 657ee5531903 ("perf evlist: Introduce side band thread")
Link: http://lkml.kernel.org/n/tip-41i888xyim9n5ceyr44jb...@git.kernel.org
Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
 tools/perf/util/evlist.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index f2bbae38278d..4b6783ff5813 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1868,12 +1868,12 @@ static void *perf_evlist__poll_thread(void *arg)
 {
        struct perf_evlist *evlist = arg;
        bool draining = false;
-       int i;
+       int i, done = 0;
+
+       while (!done) {
+               bool got_data = false;
 
-       while (draining || !(evlist->thread.done)) {
-               if (draining)
-                       draining = false;
-               else if (evlist->thread.done)
+               if (evlist->thread.done)
                        draining = true;
 
                if (!draining)
@@ -1894,9 +1894,13 @@ static void *perf_evlist__poll_thread(void *arg)
                                        pr_warning("cannot locate proper evsel 
for the side band event\n");
 
                                perf_mmap__consume(map);
+                               got_data = true;
                        }
                        perf_mmap__read_done(map);
                }
+
+               if (draining && !got_data)
+                       break;
        }
        return NULL;
 }
-- 
2.17.2