On Mon, Apr 11, 2011 at 02:50:22PM +1000, NeilBrown wrote: > diff --git a/block/blk-core.c b/block/blk-core.c > index 273d60b..903ce8d 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -2674,19 +2674,23 @@ static void flush_plug_list(struct blk_plug *plug) > struct request_queue *q; > unsigned long flags; > struct request *rq; > + struct list_head head; > > BUG_ON(plug->magic != PLUG_MAGIC); > > if (list_empty(&plug->list)) > return; > + list_add(&head, &plug->list); > + list_del_init(&plug->list); > > if (plug->should_sort) > - list_sort(NULL, &plug->list, plug_rq_cmp); > + list_sort(NULL, &head, plug_rq_cmp); > + plug->should_sort = 0; As Jens mentioned this should be list_splice_init. But looking over flush_plug_list the code there seems strange to me. What does the local_irq_save in flush_plug_list protect? Why don't we need it over the list_sort? And do we still need it when first splicing the list to a local one? It's one of these cases where I'd really like to see more comments explaining why the code is doing what it's doing. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
