[PATCH V3 08/14] perf tools: Make perf_evlist__set_maps() more resilient

From: Adrian Hunter
Date: Tue Sep 08 2015 - 04:02:28 EST


Make perf_evlist__set_maps() more resilient by allowing for the
possibility that one or another of the maps isn't being changed
and therefore should not be "put".

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/evlist.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 5bd3b49452c6..78ff52ee8788 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1155,11 +1155,22 @@ out_delete_threads:
void perf_evlist__set_maps(struct perf_evlist *evlist, struct cpu_map *cpus,
struct thread_map *threads)
{
- cpu_map__put(evlist->cpus);
- evlist->cpus = cpus;
+ /*
+ * Allow for the possibility that one or another of the maps isn't being
+ * changed i.e. don't put it. Note we are assuming the maps that are
+ * being applied are brand new and evlist is taking ownership of the
+ * original reference count of 1. If that is not the case it is up to
+ * the caller to increase the reference count.
+ */
+ if (cpus != evlist->cpus) {
+ cpu_map__put(evlist->cpus);
+ evlist->cpus = cpus;
+ }

- thread_map__put(evlist->threads);
- evlist->threads = threads;
+ if (threads != evlist->threads) {
+ thread_map__put(evlist->threads);
+ evlist->threads = threads;
+ }

perf_evlist__propagate_maps(evlist);
}
--
1.9.1

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