[PATCH] faster update_atime.

Another 2.4 forward port, original from Andrew Morton.

fs/inode.c

@@ -1196,6 +1196,8 @@ static inline void do_atime_update(struct inode *inode)
  
 void update_atime (struct inode *inode)
 {
+	if (inode->i_atime == CURRENT_TIME)
+		return;
 	if ( IS_NOATIME (inode) ) return;
 	if ( IS_NODIRATIME (inode) && S_ISDIR (inode->i_mode) ) return;
 	if ( IS_RDONLY (inode) ) return;