diff --git a/tools/perf/include/bpf/bpf.h b/tools/perf/include/bpf/bpf.h
index 04ecd425a237..bd5d7b4d7760 100644
--- a/tools/perf/include/bpf/bpf.h
+++ b/tools/perf/include/bpf/bpf.h
@@ -18,12 +18,20 @@ struct bpf_map {
         unsigned int numa_node;
 };
 
+/*
+ * FIXME: this should receive .max_entries as a parameter, as careful
+ *	  tuning of these limits is needed to avoid hitting limits that
+ *	  prevents other BPF constructs, such as tracepoint handlers,
+ *	  to get installed, with cryptic messages from libbpf, etc.
+ *	  For the current need, 'perf trace --filter-pids', 64 should
+ *	  be good enough, but this surely needs to be revisited.
+ */
 #define pid_map(name, value_type)		\
 struct bpf_map SEC("maps") name = {		\
 	.type	     = BPF_MAP_TYPE_HASH,	\
 	.key_size    = sizeof(pid_t),		\
 	.value_size  = sizeof(value_type),	\
-	.max_entries = 512,			\
+	.max_entries = 64,			\
 }
 
 static int (*bpf_map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags) = (void *)BPF_FUNC_map_update_elem;