Snap for 6416172 from d3a7616aa26eb5f0b6c46de96730305e21cd3f35 to rvc-release

Change-Id: I61b2b762ab281b5e44c36a8ebb6a6e2b28d5ca84

include/jemalloc/internal/jemalloc_internal_defs.h

diff --git a/include/jemalloc/internal/jemalloc_internal_defs.h b/include/jemalloc/internal/jemalloc_internal_defs.h
index 052bd11..37ab466 100644
--- a/include/jemalloc/internal/jemalloc_internal_defs.h
+++ b/include/jemalloc/internal/jemalloc_internal_defs.h
@@ -237,7 +237,12 @@
  * common sequences of mmap()/munmap() calls will cause virtual memory map
  * holes.
  */
+#if defined(__LP64__)
+// Only use retain for 64 bit since virtual memory can be exhausted
+// very easily when running in 32 bit.
+// See b/142556796.
 #define JEMALLOC_RETAIN 
+#endif
 
 /* TLS is used to map arenas and magazine caches to threads. */
 /* #undef JEMALLOC_TLS */