libperf: Move mmap allocation to perf_evlist__mmap_ops::get

Move allocation of the mmap array into perf_evlist__mmap_ops::get, to
centralize the mmap allocation.

Also move nr_mmap setup to perf_evlist__mmap_ops so it's centralized and
shared by both perf and libperf mmap code.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20191017105918.20873-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 9 insertions, 15 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 6cda5a311ba5..5cded4ec5806 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -599,9 +599,6 @@ static struct mmap *evlist__alloc_mmap(struct evlist *evlist,
 	int i;
 	struct mmap *map;
 
-	evlist->core.nr_mmaps = perf_cpu_map__nr(evlist->core.cpus);
-	if (perf_cpu_map__empty(evlist->core.cpus))
-		evlist->core.nr_mmaps = perf_thread_map__nr(evlist->core.threads);
 	map = zalloc(evlist->core.nr_mmaps * sizeof(struct mmap));
 	if (!map)
 		return NULL;
@@ -639,19 +636,21 @@ static struct perf_mmap*
 perf_evlist__mmap_cb_get(struct perf_evlist *_evlist, bool overwrite, int idx)
 {
 	struct evlist *evlist = container_of(_evlist, struct evlist, core);
-	struct mmap *maps = evlist->mmap;
+	struct mmap *maps;
 
-	if (overwrite) {
-		maps = evlist->overwrite_mmap;
+	maps = overwrite ? evlist->overwrite_mmap : evlist->mmap;
 
-		if (!maps) {
-			maps = evlist__alloc_mmap(evlist, true);
-			if (!maps)
-				return NULL;
+	if (!maps) {
+		maps = evlist__alloc_mmap(evlist, overwrite);
+		if (!maps)
+			return NULL;
 
+		if (overwrite) {
 			evlist->overwrite_mmap = maps;
 			if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
 				perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
+		} else {
+			evlist->mmap = maps;
 		}
 	}
 
@@ -812,11 +811,6 @@ int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
 		.mmap = perf_evlist__mmap_cb_mmap,
 	};
 
-	if (!evlist->mmap)
-		evlist->mmap = evlist__alloc_mmap(evlist, false);
-	if (!evlist->mmap)
-		return -ENOMEM;
-
 	evlist->core.mmap_len = evlist__mmap_size(pages);
 	pr_debug("mmap size %zuB\n", evlist->core.mmap_len);
 	mp.core.mask = evlist->core.mmap_len - page_size - 1;