On Thu, 23 Dec 2010 13:43:23 +0800, Huang Ying said:
> The functionality of xlist and llist is almost same.  This patch
> replace xlist with llist to avoid code duplication.

>  /*
> - * this takes a list head of mrs and turns it into an xlist of clusters.
> - * each cluster has an xlist of MR_CLUSTER_SIZE mrs that are ready for
> - * reuse.
> + * this takes a list head of mrs and turns it into linked llist nodes.
>   */

This comment change loses a lot of information.  The original 3 lines
tells me a lot about what the data structure is and what it's used for,
the replacement is a 'b +=5; /* add 5 to b */' type of comment.