2 files changed, 36 insertions, 7 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 6b13bfa7ac2c..bcf157c8a9da 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -402,7 +402,21 @@ int perf_evlist__enable_event_idx(struct perf_evlist *evlist,
                 return perf_evlist__enable_event_thread(evlist, evsel, idx);
 }
 
-static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
+static int perf_evlist__grow_pollfd(struct perf_evlist *evlist, int hint)
+{
+        int nr_fds_alloc = evlist->nr_fds_alloc + hint;
+        size_t size = sizeof(struct pollfd) * nr_fds_alloc;
+        struct pollfd *pollfd = realloc(evlist->pollfd, size);
+
+        if (pollfd == NULL)
+                return -ENOMEM;
+
+        evlist->nr_fds_alloc = nr_fds_alloc;
+        evlist->pollfd       = pollfd;
+        return 0;
+}
+
+int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 {
         int nr_cpus = cpu_map__nr(evlist->cpus);
         int nr_threads = thread_map__nr(evlist->threads);
@@ -416,16 +430,28 @@ static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
                         nfds += nr_cpus * nr_threads;
         }
 
-        evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
-        return evlist->pollfd != NULL ? 0 : -ENOMEM;
+        if (evlist->nr_fds_alloc - evlist->nr_fds < nfds &&
+            perf_evlist__grow_pollfd(evlist, nfds) < 0)
+                return -ENOMEM;
+
+        return 0;
 }
 
-void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
+int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
 {
+        /*
+         * XXX: 64 is arbitrary, just not to call realloc at each fd.
+         *      Find a better autogrowing heuristic
+         */
+        if (evlist->nr_fds == evlist->nr_fds_alloc &&
+            perf_evlist__grow_pollfd(evlist, 64) < 0)
+                return -ENOMEM;
+
         fcntl(fd, F_SETFL, O_NONBLOCK);
         evlist->pollfd[evlist->nr_fds].fd = fd;
         evlist->pollfd[evlist->nr_fds].events = POLLIN | POLLERR | POLLHUP;
         evlist->nr_fds++;
+        return 0;
 }
 
 int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
@@ -717,6 +743,7 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx,
                 evlist->mmap[idx].base = NULL;
                 return -1;
         }
+
         return 0;
 }
 
@@ -743,7 +770,8 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx,
                                 return -1;
                 }
 
-                perf_evlist__add_pollfd(evlist, fd);
+                if (perf_evlist__add_pollfd(evlist, fd) < 0)
+                        return -1;
 
                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
                     perf_evlist__id_add_fd(evlist, evsel, cpu, thread, fd) < 0)
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 1082420951f9..bbc2fd01b5c5 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -30,6 +30,7 @@ struct perf_evlist {
         int              nr_entries;
         int              nr_groups;
         int              nr_fds;
+        int              nr_fds_alloc;
         int              nr_mmaps;
         size_t           mmap_len;
         int              id_pos;
@@ -82,8 +83,8 @@ perf_evlist__find_tracepoint_by_name(struct perf_evlist *evlist,
 void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
                          int cpu, int thread, u64 id);
 
-void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd);
-
+int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd);
+int perf_evlist__alloc_pollfd(struct perf_evlist *evlist);
 int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask);
 
 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id);