[PATCH] as-iosched: reuse rq for fifo

Saves some space in arq.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>

diff --git a/block/as-iosched.c b/block/as-iosched.c
index 134545b..c266546 100644 (file)
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -131,8 +131,6 @@ struct as_data {
        unsigned long antic_expire;
 };
 
-#define list_entry_fifo(ptr)   list_entry((ptr), struct as_rq, fifo)
-
 /*
  * per-request data.
  */
@@ -153,12 +151,6 @@ struct as_rq {
 
        struct io_context *io_context;  /* The submitting task */
 
-       /*
-        * expire fifo
-        */
-       struct list_head fifo;
-       unsigned long expires;
-
        unsigned int is_sync;
        enum arq_state state;
 };
@@ -893,7 +885,7 @@ static void as_remove_queued_request(request_queue_t *q, struct request *rq)
        if (ad->next_arq[data_dir] == arq)
                ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
 
-       list_del_init(&arq->fifo);
+       rq_fifo_clear(rq);
        as_del_arq_rb(ad, rq);
 }
 
@@ -907,7 +899,7 @@ static void as_remove_queued_request(request_queue_t *q, struct request *rq)
  */
 static int as_fifo_expired(struct as_data *ad, int adir)
 {
-       struct as_rq *arq;
+       struct request *rq;
        long delta_jif;
 
        delta_jif = jiffies - ad->last_check_fifo[adir];
@@ -921,9 +913,9 @@ static int as_fifo_expired(struct as_data *ad, int adir)
        if (list_empty(&ad->fifo_list[adir]))
                return 0;
 
-       arq = list_entry_fifo(ad->fifo_list[adir].next);
+       rq = rq_entry_fifo(ad->fifo_list[adir].next);
 
-       return time_after(jiffies, arq->expires);
+       return time_after(jiffies, rq_fifo_time(rq));
 }
 
 /*
@@ -1089,7 +1081,7 @@ static int as_dispatch_request(request_queue_t *q, int force)
                        ad->changed_batch = 1;
                }
                ad->batch_data_dir = REQ_SYNC;
-               arq = list_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);
+               arq = RQ_DATA(rq_entry_fifo(ad->fifo_list[REQ_SYNC].next));
                ad->last_check_fifo[ad->batch_data_dir] = jiffies;
                goto dispatch_request;
        }
@@ -1129,8 +1121,7 @@ dispatch_request:
 
        if (as_fifo_expired(ad, ad->batch_data_dir)) {
 fifo_expired:
-               arq = list_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);
-               BUG_ON(arq == NULL);
+               arq = RQ_DATA(rq_entry_fifo(ad->fifo_list[ad->batch_data_dir].next));
        }
 
        if (ad->changed_batch) {
@@ -1186,8 +1177,8 @@ static void as_add_request(request_queue_t *q, struct request *rq)
        /*
         * set expire time (only used for reads) and add to fifo list
         */
-       arq->expires = jiffies + ad->fifo_expire[data_dir];
-       list_add_tail(&arq->fifo, &ad->fifo_list[data_dir]);
+       rq_set_fifo_time(rq, jiffies + ad->fifo_expire[data_dir]);
+       list_add_tail(&rq->queuelist, &ad->fifo_list[data_dir]);
 
        as_update_arq(ad, arq); /* keep state machine up to date */
        arq->state = AS_RQ_QUEUED;
@@ -1277,10 +1268,10 @@ static void as_merged_requests(request_queue_t *q, struct request *req,
         * if anext expires before arq, assign its expire time to arq
         * and move into anext position (anext will be deleted) in fifo
         */
-       if (!list_empty(&arq->fifo) && !list_empty(&anext->fifo)) {
-               if (time_before(anext->expires, arq->expires)) {
-                       list_move(&arq->fifo, &anext->fifo);
-                       arq->expires = anext->expires;
+       if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
+               if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
+                       list_move(&req->queuelist, &next->queuelist);
+                       rq_set_fifo_time(req, rq_fifo_time(next));
                        /*
                         * Don't copy here but swap, because when anext is
                         * removed below, it must contain the unused context
@@ -1350,7 +1341,6 @@ static int as_set_request(request_queue_t *q, struct request *rq,
                arq->request = rq;
                arq->state = AS_RQ_PRESCHED;
                arq->io_context = NULL;
-               INIT_LIST_HEAD(&arq->fifo);
                rq->elevator_private = arq;
                return 0;
        }