[PATCH v15 06/12] perf tools: Alloc backward_mmap array for evlist

[Wang Nan]

Add backward_mmap to evlist. Alloc this array in perf_evlist__mmap_ex()
and free it together with normal mmap.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: Nilay Vaish <nilayvaish@xxxxxxxxx>
Cc: pi3orama@xxxxxxx
---
 tools/perf/util/evlist.c | 18 +++++++++++++-----
 tools/perf/util/evlist.h |  1 +
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index bbad72f..53c25a4 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -123,6 +123,7 @@ static void perf_evlist__purge(struct perf_evlist *evlist)
 void perf_evlist__exit(struct perf_evlist *evlist)
 {
 	zfree(&evlist->mmap);
+	zfree(&evlist->backward_mmap);
 	fdarray__exit(&evlist->pollfd);
 }
 
@@ -962,17 +963,20 @@ static void perf_evlist__munmap_nofree(struct perf_evlist *evlist)
 {
 	int i;
 
-	if (evlist->mmap == NULL)
-		return;
+	if (evlist->mmap)
+		for (i = 0; i < evlist->nr_mmaps; i++)
+			perf_mmap__munmap(&evlist->mmap[i]);
 
-	for (i = 0; i < evlist->nr_mmaps; i++)
-		perf_mmap__munmap(&evlist->mmap[i]);
+	if (evlist->backward_mmap)
+		for (i = 0; i < evlist->nr_mmaps; i++)
+			perf_mmap__munmap(&evlist->backward_mmap[i]);
 }
 
 void perf_evlist__munmap(struct perf_evlist *evlist)
 {
 	perf_evlist__munmap_nofree(evlist);
 	zfree(&evlist->mmap);
+	zfree(&evlist->backward_mmap);
 }
 
 static struct perf_mmap *perf_evlist__alloc_mmap(struct perf_evlist *evlist)
@@ -1289,8 +1293,12 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
 
 	if (!evlist->mmap)
 		evlist->mmap = perf_evlist__alloc_mmap(evlist);
-	if (!evlist->mmap)
+	if (!evlist->backward_mmap)
+		evlist->backward_mmap = perf_evlist__alloc_mmap(evlist);
+	if (!evlist->mmap || !evlist->backward_mmap) {
+		perf_evlist__munmap(evlist);
 		return -ENOMEM;
+	}
 
 	if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
 		return -ENOMEM;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 2fc5c16..8acac5f 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -61,6 +61,7 @@ struct perf_evlist {
 	} workload;
 	struct fdarray	 pollfd;
 	struct perf_mmap *mmap;
+	struct perf_mmap *backward_mmap;
 	struct thread_map *threads;
 	struct cpu_map	  *cpus;
 	struct perf_evsel *selected;
-- 
1.8.3.4