diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a728fc492557..d00d42d6bf79 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1577,6 +1577,8 @@ void vfree_atomic(const void *addr)
  *	have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
  *	conventions for vfree() arch-depenedent would be a really bad idea)
  *
+ *	May sleep if called *not* from interrupt context.
+ *
  *	NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
  */
 void vfree(const void *addr)