Update Linux to v5.10.157

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.157.tar.xz

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I7b30d9e98d8c465d6b44de8e7433b4a40b3289ba
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 8d04e7d..297744e 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -39,12 +39,15 @@
 	atomic_t refcount;
 
 	/*
-	 * Count of child anon_vmas and VMAs which points to this anon_vma.
+	 * Count of child anon_vmas. Equals to the count of all anon_vmas that
+	 * have ->parent pointing to this one, including itself.
 	 *
 	 * This counter is used for making decision about reusing anon_vma
 	 * instead of forking new one. See comments in function anon_vma_clone.
 	 */
-	unsigned degree;
+	unsigned long num_children;
+	/* Count of VMAs whose ->anon_vma pointer points to this object. */
+	unsigned long num_active_vmas;
 
 	struct anon_vma *parent;	/* Parent of this anon_vma */