perf evlist: Fix inverted logic in perf_mmap__empty

perf_evlist__mmap_consume() uses perf_mmap__empty() to judge whether
perf_mmap is empty and can be released. But the result is inverted so
fix it.

Signed-off-by: He Kuang <hekuang@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1428399071-7141-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 82bf224bbee934ef1ed9f09619acf985de9a26e9..76ef7ee62640d0b1cb4a85a667faea4b576d2014 100644 (file)
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -695,7 +695,7 @@ union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
 
 static bool perf_mmap__empty(struct perf_mmap *md)
 {
-       return perf_mmap__read_head(md) != md->prev;
+       return perf_mmap__read_head(md) == md->prev;
 }
 
 static void perf_evlist__mmap_get(struct perf_evlist *evlist, int idx)