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authorJiri Olsa <jolsa@kernel.org>2019-10-07 14:53:30 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-10-10 12:52:41 -0300
commit285aaeac8c5d537b56b70169e21ac29ae5caa8e1 (patch)
tree575d94a0ff5dbe0be84cf4d8e4475d26e4c74f3f /tools/perf/lib
parent923d0f1868cb331d660fb569ecd00c39889905f6 (diff)
libperf: Centralize map refcnt setting
Currently when a new map is mmapped we set its refcnt to 2 in the perf_evlist_mmap_ops::mmap callback. Every mmap gets its refcnt set to 2 when it's first mmaped: - 1 for the current user, which will be taken out by a call to perf_evlist__munmap_filtered(), where we find out there's no more data comming from kernel to this mmap. - 1 for the drain code where in perf_mmap__consume() the mmap is released if it is empty. Move this common setup into libperf's generic code before the mmap callback is called. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lore.kernel.org/lkml/20191007125344.14268-23-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/lib')
-rw-r--r--tools/perf/lib/evlist.c30
1 files changed, 15 insertions, 15 deletions
diff --git a/tools/perf/lib/evlist.c b/tools/perf/lib/evlist.c
index b69722627779..f9a802d2ceb5 100644
--- a/tools/perf/lib/evlist.c
+++ b/tools/perf/lib/evlist.c
@@ -362,21 +362,6 @@ static int
perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
int output, int cpu)
{
- /*
- * The last one will be done at perf_mmap__consume(), so that we
- * make sure we don't prevent tools from consuming every last event in
- * the ring buffer.
- *
- * I.e. we can get the POLLHUP meaning that the fd doesn't exist
- * anymore, but the last events for it are still in the ring buffer,
- * waiting to be consumed.
- *
- * Tools can chose to ignore this at their own discretion, but the
- * evlist layer can't just drop it when filtering events in
- * perf_evlist__filter_pollfd().
- */
- refcount_set(&map->refcnt, 2);
-
return perf_mmap__mmap(map, mp, output, cpu);
}
@@ -418,6 +403,21 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
if (*output == -1) {
*output = fd;
+ /*
+ * The last one will be done at perf_mmap__consume(), so that we
+ * make sure we don't prevent tools from consuming every last event in
+ * the ring buffer.
+ *
+ * I.e. we can get the POLLHUP meaning that the fd doesn't exist
+ * anymore, but the last events for it are still in the ring buffer,
+ * waiting to be consumed.
+ *
+ * Tools can chose to ignore this at their own discretion, but the
+ * evlist layer can't just drop it when filtering events in
+ * perf_evlist__filter_pollfd().
+ */
+ refcount_set(&map->refcnt, 2);
+
if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
return -1;
} else {