[PATCH] as-iosched: kill arq

Get rid of the as_rq request type. With the added elevator_private2, we
have enough room in struct request to get rid of any arq allocation/free
for each request.

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 dca0b0563ca0752c01ef8603a3f25c3a0f1f190d..02eb9333898f38fa829b345c68365e01f9f440a7 100644 (file)
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -92,7 +92,7 @@ struct as_data {
        struct rb_root sort_list[2];
        struct list_head fifo_list[2];
 
        struct rb_root sort_list[2];
        struct list_head fifo_list[2];
 

-       struct as_rq *next_arq[2];      /* next in sort order */
+       struct request *next_rq[2];     /* next in sort order */

        sector_t last_sector[2];        /* last REQ_SYNC & REQ_ASYNC sectors */
 
        unsigned long exit_prob;        /* probability a task will exit while
        sector_t last_sector[2];        /* last REQ_SYNC & REQ_ASYNC sectors */
 
        unsigned long exit_prob;        /* probability a task will exit while


@@ -113,7 +113,6 @@ struct as_data {
        int write_batch_count;          /* max # of reqs in a write batch */
        int current_write_count;        /* how many requests left this batch */
        int write_batch_idled;          /* has the write batch gone idle? */
        int write_batch_count;          /* max # of reqs in a write batch */
        int current_write_count;        /* how many requests left this batch */
        int write_batch_idled;          /* has the write batch gone idle? */

-       mempool_t *arq_pool;

 
        enum anticipation_status antic_status;
        unsigned long antic_start;      /* jiffies: when it started */
 
        enum anticipation_status antic_status;
        unsigned long antic_start;      /* jiffies: when it started */


@@ -146,22 +145,14 @@ enum arq_state {
        AS_RQ_POSTSCHED,        /* when they shouldn't be */
 };
 
        AS_RQ_POSTSCHED,        /* when they shouldn't be */
 };
 

-struct as_rq {
-       struct request *request;
-
-       struct io_context *io_context;  /* The submitting task */
-
-       enum arq_state state;
-};
-
-#define RQ_DATA(rq)    ((struct as_rq *) (rq)->elevator_private)
-
-static kmem_cache_t *arq_pool;
+#define RQ_IOC(rq)     ((struct io_context *) (rq)->elevator_private)
+#define RQ_STATE(rq)   ((enum arq_state)(rq)->elevator_private2)
+#define RQ_SET_STATE(rq, state)        ((rq)->elevator_private2 = (void *) state)

 
 static atomic_t ioc_count = ATOMIC_INIT(0);
 static struct completion *ioc_gone;
 
 
 static atomic_t ioc_count = ATOMIC_INIT(0);
 static struct completion *ioc_gone;
 

-static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq);
+static void as_move_to_dispatch(struct as_data *ad, struct request *rq);

 static void as_antic_stop(struct as_data *ad);
 
 /*
 static void as_antic_stop(struct as_data *ad);
 
 /*


@@ -231,23 +222,23 @@ static struct io_context *as_get_io_context(void)
        return ioc;
 }
 
        return ioc;
 }
 

-static void as_put_io_context(struct as_rq *arq)
+static void as_put_io_context(struct request *rq)

 {
        struct as_io_context *aic;
 
 {
        struct as_io_context *aic;
 

-       if (unlikely(!arq->io_context))
+       if (unlikely(!RQ_IOC(rq)))

                return;
 
                return;
 

-       aic = arq->io_context->aic;
+       aic = RQ_IOC(rq)->aic;

 
 

-       if (rq_is_sync(arq->request) && aic) {
+       if (rq_is_sync(rq) && aic) {

                spin_lock(&aic->lock);
                set_bit(AS_TASK_IORUNNING, &aic->state);
                aic->last_end_request = jiffies;
                spin_unlock(&aic->lock);
        }
 
                spin_lock(&aic->lock);
                set_bit(AS_TASK_IORUNNING, &aic->state);
                aic->last_end_request = jiffies;
                spin_unlock(&aic->lock);
        }
 

-       put_io_context(arq->io_context);
+       put_io_context(RQ_IOC(rq));

 }
 
 /*
 }
 
 /*


@@ -255,17 +246,17 @@ static void as_put_io_context(struct as_rq *arq)
  */
 #define RQ_RB_ROOT(ad, rq)     (&(ad)->sort_list[rq_is_sync((rq))])
 
  */
 #define RQ_RB_ROOT(ad, rq)     (&(ad)->sort_list[rq_is_sync((rq))])
 

-static void as_add_arq_rb(struct as_data *ad, struct request *rq)
+static void as_add_rq_rb(struct as_data *ad, struct request *rq)

 {
        struct request *alias;
 
        while ((unlikely(alias = elv_rb_add(RQ_RB_ROOT(ad, rq), rq)))) {
 {
        struct request *alias;
 
        while ((unlikely(alias = elv_rb_add(RQ_RB_ROOT(ad, rq), rq)))) {

-               as_move_to_dispatch(ad, RQ_DATA(alias));
+               as_move_to_dispatch(ad, alias);

                as_antic_stop(ad);
        }
 }
 
                as_antic_stop(ad);
        }
 }
 

-static inline void as_del_arq_rb(struct as_data *ad, struct request *rq)
+static inline void as_del_rq_rb(struct as_data *ad, struct request *rq)

 {
        elv_rb_del(RQ_RB_ROOT(ad, rq), rq);
 }
 {
        elv_rb_del(RQ_RB_ROOT(ad, rq), rq);
 }


@@ -285,26 +276,26 @@ static inline void as_del_arq_rb(struct as_data *ad, struct request *rq)
  * as_choose_req selects the preferred one of two requests of the same data_dir
  * ignoring time - eg. timeouts, which is the job of as_dispatch_request
  */
  * as_choose_req selects the preferred one of two requests of the same data_dir
  * ignoring time - eg. timeouts, which is the job of as_dispatch_request
  */

-static struct as_rq *
-as_choose_req(struct as_data *ad, struct as_rq *arq1, struct as_rq *arq2)
+static struct request *
+as_choose_req(struct as_data *ad, struct request *rq1, struct request *rq2)

 {
        int data_dir;
        sector_t last, s1, s2, d1, d2;
        int r1_wrap=0, r2_wrap=0;       /* requests are behind the disk head */
        const sector_t maxback = MAXBACK;
 
 {
        int data_dir;
        sector_t last, s1, s2, d1, d2;
        int r1_wrap=0, r2_wrap=0;       /* requests are behind the disk head */
        const sector_t maxback = MAXBACK;
 

-       if (arq1 == NULL || arq1 == arq2)
-               return arq2;
-       if (arq2 == NULL)
-               return arq1;
+       if (rq1 == NULL || rq1 == rq2)
+               return rq2;
+       if (rq2 == NULL)
+               return rq1;

 
 

-       data_dir = rq_is_sync(arq1->request);
+       data_dir = rq_is_sync(rq1);

 
        last = ad->last_sector[data_dir];
 
        last = ad->last_sector[data_dir];

-       s1 = arq1->request->sector;
-       s2 = arq2->request->sector;
+       s1 = rq1->sector;
+       s2 = rq2->sector;

 
 

-       BUG_ON(data_dir != rq_is_sync(arq2->request));
+       BUG_ON(data_dir != rq_is_sync(rq2));

 
        /*
         * Strict one way elevator _except_ in the case where we allow
 
        /*
         * Strict one way elevator _except_ in the case where we allow


@@ -331,55 +322,55 @@ as_choose_req(struct as_data *ad, struct as_rq *arq1, struct as_rq *arq2)
 
        /* Found required data */
        if (!r1_wrap && r2_wrap)
 
        /* Found required data */
        if (!r1_wrap && r2_wrap)

-               return arq1;
+               return rq1;

        else if (!r2_wrap && r1_wrap)
        else if (!r2_wrap && r1_wrap)

-               return arq2;
+               return rq2;

        else if (r1_wrap && r2_wrap) {
                /* both behind the head */
                if (s1 <= s2)
        else if (r1_wrap && r2_wrap) {
                /* both behind the head */
                if (s1 <= s2)

-                       return arq1;
+                       return rq1;

                else
                else

-                       return arq2;
+                       return rq2;

        }
 
        /* Both requests in front of the head */
        if (d1 < d2)
        }
 
        /* Both requests in front of the head */
        if (d1 < d2)

-               return arq1;
+               return rq1;

        else if (d2 < d1)
        else if (d2 < d1)

-               return arq2;
+               return rq2;

        else {
                if (s1 >= s2)
        else {
                if (s1 >= s2)

-                       return arq1;
+                       return rq1;

                else
                else

-                       return arq2;
+                       return rq2;

        }
 }
 
 /*
        }
 }
 
 /*

- * as_find_next_arq finds the next request after @prev in elevator order.
+ * as_find_next_rq finds the next request after @prev in elevator order.

  * this with as_choose_req form the basis for how the scheduler chooses
  * what request to process next. Anticipation works on top of this.
  */
  * this with as_choose_req form the basis for how the scheduler chooses
  * what request to process next. Anticipation works on top of this.
  */

-static struct as_rq *as_find_next_arq(struct as_data *ad, struct as_rq *arq)
+static struct request *
+as_find_next_rq(struct as_data *ad, struct request *last)

 {
 {

-       struct request *last = arq->request;

        struct rb_node *rbnext = rb_next(&last->rb_node);
        struct rb_node *rbprev = rb_prev(&last->rb_node);
        struct rb_node *rbnext = rb_next(&last->rb_node);
        struct rb_node *rbprev = rb_prev(&last->rb_node);

-       struct as_rq *next = NULL, *prev = NULL;
+       struct request *next = NULL, *prev = NULL;

 
        BUG_ON(RB_EMPTY_NODE(&last->rb_node));
 
        if (rbprev)
 
        BUG_ON(RB_EMPTY_NODE(&last->rb_node));
 
        if (rbprev)

-               prev = RQ_DATA(rb_entry_rq(rbprev));
+               prev = rb_entry_rq(rbprev);

 
        if (rbnext)
 
        if (rbnext)

-               next = RQ_DATA(rb_entry_rq(rbnext));
+               next = rb_entry_rq(rbnext);

        else {
                const int data_dir = rq_is_sync(last);
 
                rbnext = rb_first(&ad->sort_list[data_dir]);
                if (rbnext && rbnext != &last->rb_node)
        else {
                const int data_dir = rq_is_sync(last);
 
                rbnext = rb_first(&ad->sort_list[data_dir]);
                if (rbnext && rbnext != &last->rb_node)

-                       next = RQ_DATA(rb_entry_rq(rbnext));
+                       next = rb_entry_rq(rbnext);

        }
 
        return as_choose_req(ad, next, prev);
        }
 
        return as_choose_req(ad, next, prev);


@@ -575,11 +566,11 @@ static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
  * previous one issued.
  */
 static int as_close_req(struct as_data *ad, struct as_io_context *aic,
  * previous one issued.
  */
 static int as_close_req(struct as_data *ad, struct as_io_context *aic,

-                               struct as_rq *arq)
+                       struct request *rq)

 {
        unsigned long delay;    /* milliseconds */
        sector_t last = ad->last_sector[ad->batch_data_dir];
 {
        unsigned long delay;    /* milliseconds */
        sector_t last = ad->last_sector[ad->batch_data_dir];

-       sector_t next = arq->request->sector;
+       sector_t next = rq->sector;

        sector_t delta; /* acceptable close offset (in sectors) */
        sector_t s;
 
        sector_t delta; /* acceptable close offset (in sectors) */
        sector_t s;
 


@@ -636,7 +627,7 @@ static int as_close_req(struct as_data *ad, struct as_io_context *aic,
  *
  * If this task has queued some other IO, do not enter enticipation.
  */
  *
  * If this task has queued some other IO, do not enter enticipation.
  */

-static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
+static int as_can_break_anticipation(struct as_data *ad, struct request *rq)

 {
        struct io_context *ioc;
        struct as_io_context *aic;
 {
        struct io_context *ioc;
        struct as_io_context *aic;


@@ -644,7 +635,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
        ioc = ad->io_context;
        BUG_ON(!ioc);
 
        ioc = ad->io_context;
        BUG_ON(!ioc);
 

-       if (arq && ioc == arq->io_context) {
+       if (rq && ioc == RQ_IOC(rq)) {

                /* request from same process */
                return 1;
        }
                /* request from same process */
                return 1;
        }


@@ -671,7 +662,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
                return 1;
        }
 
                return 1;
        }
 

-       if (arq && rq_is_sync(arq->request) && as_close_req(ad, aic, arq)) {
+       if (rq && rq_is_sync(rq) && as_close_req(ad, aic, rq)) {

                /*
                 * Found a close request that is not one of ours.
                 *
                /*
                 * Found a close request that is not one of ours.
                 *


@@ -687,7 +678,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
                        ad->exit_no_coop = (7*ad->exit_no_coop)/8;
                }
 
                        ad->exit_no_coop = (7*ad->exit_no_coop)/8;
                }
 

-               as_update_iohist(ad, aic, arq->request);
+               as_update_iohist(ad, aic, rq);

                return 1;
        }
 
                return 1;
        }
 


@@ -714,10 +705,10 @@ static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
 }
 
 /*
 }
 
 /*

- * as_can_anticipate indicates whether we should either run arq
+ * as_can_anticipate indicates whether we should either run rq

  * or keep anticipating a better request.
  */
  * or keep anticipating a better request.
  */

-static int as_can_anticipate(struct as_data *ad, struct as_rq *arq)
+static int as_can_anticipate(struct as_data *ad, struct request *rq)

 {
        if (!ad->io_context)
                /*
 {
        if (!ad->io_context)
                /*


@@ -731,7 +722,7 @@ static int as_can_anticipate(struct as_data *ad, struct as_rq *arq)
                 */
                return 0;
 
                 */
                return 0;
 

-       if (as_can_break_anticipation(ad, arq))
+       if (as_can_break_anticipation(ad, rq))

                /*
                 * This request is a good candidate. Don't keep anticipating,
                 * run it.
                /*
                 * This request is a good candidate. Don't keep anticipating,
                 * run it.


@@ -749,16 +740,16 @@ static int as_can_anticipate(struct as_data *ad, struct as_rq *arq)
 }
 
 /*
 }
 
 /*

- * as_update_arq must be called whenever a request (arq) is added to
+ * as_update_rq must be called whenever a request (rq) is added to

  * the sort_list. This function keeps caches up to date, and checks if the
  * request might be one we are "anticipating"
  */
  * the sort_list. This function keeps caches up to date, and checks if the
  * request might be one we are "anticipating"
  */

-static void as_update_arq(struct as_data *ad, struct as_rq *arq)
+static void as_update_rq(struct as_data *ad, struct request *rq)

 {
 {

-       const int data_dir = rq_is_sync(arq->request);
+       const int data_dir = rq_is_sync(rq);

 
 

-       /* keep the next_arq cache up to date */
-       ad->next_arq[data_dir] = as_choose_req(ad, arq, ad->next_arq[data_dir]);
+       /* keep the next_rq cache up to date */
+       ad->next_rq[data_dir] = as_choose_req(ad, rq, ad->next_rq[data_dir]);

 
        /*
         * have we been anticipating this request?
 
        /*
         * have we been anticipating this request?


@@ -767,7 +758,7 @@ static void as_update_arq(struct as_data *ad, struct as_rq *arq)
         */
        if (ad->antic_status == ANTIC_WAIT_REQ
                        || ad->antic_status == ANTIC_WAIT_NEXT) {
         */
        if (ad->antic_status == ANTIC_WAIT_REQ
                        || ad->antic_status == ANTIC_WAIT_NEXT) {

-               if (as_can_break_anticipation(ad, arq))
+               if (as_can_break_anticipation(ad, rq))

                        as_antic_stop(ad);
        }
 }
                        as_antic_stop(ad);
        }
 }


@@ -807,12 +798,11 @@ static void update_write_batch(struct as_data *ad)
 static void as_completed_request(request_queue_t *q, struct request *rq)
 {
        struct as_data *ad = q->elevator->elevator_data;
 static void as_completed_request(request_queue_t *q, struct request *rq)
 {
        struct as_data *ad = q->elevator->elevator_data;

-       struct as_rq *arq = RQ_DATA(rq);

 
        WARN_ON(!list_empty(&rq->queuelist));
 
 
        WARN_ON(!list_empty(&rq->queuelist));
 

-       if (arq->state != AS_RQ_REMOVED) {
-               printk("arq->state %d\n", arq->state);
+       if (RQ_STATE(rq) != AS_RQ_REMOVED) {
+               printk("rq->state %d\n", RQ_STATE(rq));

                WARN_ON(1);
                goto out;
        }
                WARN_ON(1);
                goto out;
        }


@@ -839,7 +829,7 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
                ad->new_batch = 0;
        }
 
                ad->new_batch = 0;
        }
 

-       if (ad->io_context == arq->io_context && ad->io_context) {
+       if (ad->io_context == RQ_IOC(rq) && ad->io_context) {

                ad->antic_start = jiffies;
                ad->ioc_finished = 1;
                if (ad->antic_status == ANTIC_WAIT_REQ) {
                ad->antic_start = jiffies;
                ad->ioc_finished = 1;
                if (ad->antic_status == ANTIC_WAIT_REQ) {


@@ -851,9 +841,9 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
                }
        }
 
                }
        }
 

-       as_put_io_context(arq);
+       as_put_io_context(rq);

 out:
 out:

-       arq->state = AS_RQ_POSTSCHED;
+       RQ_SET_STATE(rq, AS_RQ_POSTSCHED);

 }
 
 /*
 }
 
 /*


@@ -864,26 +854,27 @@ out:
  */
 static void as_remove_queued_request(request_queue_t *q, struct request *rq)
 {
  */
 static void as_remove_queued_request(request_queue_t *q, struct request *rq)
 {

-       struct as_rq *arq = RQ_DATA(rq);

        const int data_dir = rq_is_sync(rq);
        struct as_data *ad = q->elevator->elevator_data;
        const int data_dir = rq_is_sync(rq);
        struct as_data *ad = q->elevator->elevator_data;

+       struct io_context *ioc;

 
 

-       WARN_ON(arq->state != AS_RQ_QUEUED);
+       WARN_ON(RQ_STATE(rq) != AS_RQ_QUEUED);

 
 

-       if (arq->io_context && arq->io_context->aic) {
-               BUG_ON(!atomic_read(&arq->io_context->aic->nr_queued));
-               atomic_dec(&arq->io_context->aic->nr_queued);
+       ioc = RQ_IOC(rq);
+       if (ioc && ioc->aic) {
+               BUG_ON(!atomic_read(&ioc->aic->nr_queued));
+               atomic_dec(&ioc->aic->nr_queued);

        }
 
        /*
        }
 
        /*

-        * Update the "next_arq" cache if we are about to remove its
+        * Update the "next_rq" cache if we are about to remove its

         * entry
         */
         * entry
         */

-       if (ad->next_arq[data_dir] == arq)
-               ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
+       if (ad->next_rq[data_dir] == rq)
+               ad->next_rq[data_dir] = as_find_next_rq(ad, rq);

 
        rq_fifo_clear(rq);
 
        rq_fifo_clear(rq);

-       as_del_arq_rb(ad, rq);
+       as_del_rq_rb(ad, rq);

 }
 
 /*
 }
 
 /*


@@ -935,9 +926,8 @@ static inline int as_batch_expired(struct as_data *ad)
 /*
  * move an entry to dispatch queue
  */
 /*
  * move an entry to dispatch queue
  */

-static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
+static void as_move_to_dispatch(struct as_data *ad, struct request *rq)

 {
 {

-       struct request *rq = arq->request;

        const int data_dir = rq_is_sync(rq);
 
        BUG_ON(RB_EMPTY_NODE(&rq->rb_node));
        const int data_dir = rq_is_sync(rq);
 
        BUG_ON(RB_EMPTY_NODE(&rq->rb_node));


@@ -947,13 +937,14 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
 
        /*
         * This has to be set in order to be correctly updated by
 
        /*
         * This has to be set in order to be correctly updated by

-        * as_find_next_arq
+        * as_find_next_rq

         */
        ad->last_sector[data_dir] = rq->sector + rq->nr_sectors;
 
        if (data_dir == REQ_SYNC) {
         */
        ad->last_sector[data_dir] = rq->sector + rq->nr_sectors;
 
        if (data_dir == REQ_SYNC) {

+               struct io_context *ioc = RQ_IOC(rq);

                /* In case we have to anticipate after this */
                /* In case we have to anticipate after this */

-               copy_io_context(&ad->io_context, &arq->io_context);
+               copy_io_context(&ad->io_context, &ioc);

        } else {
                if (ad->io_context) {
                        put_io_context(ad->io_context);
        } else {
                if (ad->io_context) {
                        put_io_context(ad->io_context);


@@ -965,19 +956,19 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
        }
        ad->ioc_finished = 0;
 
        }
        ad->ioc_finished = 0;
 

-       ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
+       ad->next_rq[data_dir] = as_find_next_rq(ad, rq);

 
        /*
         * take it off the sort and fifo list, add to dispatch queue
         */
        as_remove_queued_request(ad->q, rq);
 
        /*
         * take it off the sort and fifo list, add to dispatch queue
         */
        as_remove_queued_request(ad->q, rq);

-       WARN_ON(arq->state != AS_RQ_QUEUED);
+       WARN_ON(RQ_STATE(rq) != AS_RQ_QUEUED);

 
        elv_dispatch_sort(ad->q, rq);
 
 
        elv_dispatch_sort(ad->q, rq);
 

-       arq->state = AS_RQ_DISPATCHED;
-       if (arq->io_context && arq->io_context->aic)
-               atomic_inc(&arq->io_context->aic->nr_dispatched);
+       RQ_SET_STATE(rq, AS_RQ_DISPATCHED);
+       if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+               atomic_inc(&RQ_IOC(rq)->aic->nr_dispatched);

        ad->nr_dispatched++;
 }
 
        ad->nr_dispatched++;
 }
 


@@ -989,9 +980,9 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
 static int as_dispatch_request(request_queue_t *q, int force)
 {
        struct as_data *ad = q->elevator->elevator_data;
 static int as_dispatch_request(request_queue_t *q, int force)
 {
        struct as_data *ad = q->elevator->elevator_data;

-       struct as_rq *arq;

        const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
        const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);
        const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
        const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);

+       struct request *rq;

 
        if (unlikely(force)) {
                /*
 
        if (unlikely(force)) {
                /*


@@ -1007,14 +998,14 @@ static int as_dispatch_request(request_queue_t *q, int force)
                ad->changed_batch = 0;
                ad->new_batch = 0;
 
                ad->changed_batch = 0;
                ad->new_batch = 0;
 

-               while (ad->next_arq[REQ_SYNC]) {
-                       as_move_to_dispatch(ad, ad->next_arq[REQ_SYNC]);
+               while (ad->next_rq[REQ_SYNC]) {
+                       as_move_to_dispatch(ad, ad->next_rq[REQ_SYNC]);

                        dispatched++;
                }
                ad->last_check_fifo[REQ_SYNC] = jiffies;
 
                        dispatched++;
                }
                ad->last_check_fifo[REQ_SYNC] = jiffies;
 

-               while (ad->next_arq[REQ_ASYNC]) {
-                       as_move_to_dispatch(ad, ad->next_arq[REQ_ASYNC]);
+               while (ad->next_rq[REQ_ASYNC]) {
+                       as_move_to_dispatch(ad, ad->next_rq[REQ_ASYNC]);

                        dispatched++;
                }
                ad->last_check_fifo[REQ_ASYNC] = jiffies;
                        dispatched++;
                }
                ad->last_check_fifo[REQ_ASYNC] = jiffies;


@@ -1038,19 +1029,19 @@ static int as_dispatch_request(request_queue_t *q, int force)
                /*
                 * batch is still running or no reads or no writes
                 */
                /*
                 * batch is still running or no reads or no writes
                 */

-               arq = ad->next_arq[ad->batch_data_dir];
+               rq = ad->next_rq[ad->batch_data_dir];

 
                if (ad->batch_data_dir == REQ_SYNC && ad->antic_expire) {
                        if (as_fifo_expired(ad, REQ_SYNC))
                                goto fifo_expired;
 
 
                if (ad->batch_data_dir == REQ_SYNC && ad->antic_expire) {
                        if (as_fifo_expired(ad, REQ_SYNC))
                                goto fifo_expired;
 

-                       if (as_can_anticipate(ad, arq)) {
+                       if (as_can_anticipate(ad, rq)) {

                                as_antic_waitreq(ad);
                                return 0;
                        }
                }
 
                                as_antic_waitreq(ad);
                                return 0;
                        }
                }
 

-               if (arq) {
+               if (rq) {

                        /* we have a "next request" */
                        if (reads && !writes)
                                ad->current_batch_expires =
                        /* we have a "next request" */
                        if (reads && !writes)
                                ad->current_batch_expires =


@@ -1078,7 +1069,7 @@ static int as_dispatch_request(request_queue_t *q, int force)
                        ad->changed_batch = 1;
                }
                ad->batch_data_dir = REQ_SYNC;
                        ad->changed_batch = 1;
                }
                ad->batch_data_dir = REQ_SYNC;

-               arq = RQ_DATA(rq_entry_fifo(ad->fifo_list[REQ_SYNC].next));
+               rq = rq_entry_fifo(ad->fifo_list[REQ_SYNC].next);

                ad->last_check_fifo[ad->batch_data_dir] = jiffies;
                goto dispatch_request;
        }
                ad->last_check_fifo[ad->batch_data_dir] = jiffies;
                goto dispatch_request;
        }


@@ -1104,7 +1095,7 @@ dispatch_writes:
                ad->batch_data_dir = REQ_ASYNC;
                ad->current_write_count = ad->write_batch_count;
                ad->write_batch_idled = 0;
                ad->batch_data_dir = REQ_ASYNC;
                ad->current_write_count = ad->write_batch_count;
                ad->write_batch_idled = 0;

-               arq = ad->next_arq[ad->batch_data_dir];
+               rq = ad->next_rq[ad->batch_data_dir];

                goto dispatch_request;
        }
 
                goto dispatch_request;
        }
 


@@ -1118,7 +1109,7 @@ dispatch_request:
 
        if (as_fifo_expired(ad, ad->batch_data_dir)) {
 fifo_expired:
 
        if (as_fifo_expired(ad, ad->batch_data_dir)) {
 fifo_expired:

-               arq = RQ_DATA(rq_entry_fifo(ad->fifo_list[ad->batch_data_dir].next));
+               rq = rq_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);

        }
 
        if (ad->changed_batch) {
        }
 
        if (ad->changed_batch) {


@@ -1137,34 +1128,33 @@ fifo_expired:
        }
 
        /*
        }
 
        /*

-        * arq is the selected appropriate request.
+        * rq is the selected appropriate request.

         */
         */

-       as_move_to_dispatch(ad, arq);
+       as_move_to_dispatch(ad, rq);

 
        return 1;
 }
 
 /*
 
        return 1;
 }
 
 /*

- * add arq to rbtree and fifo
+ * add rq to rbtree and fifo

  */
 static void as_add_request(request_queue_t *q, struct request *rq)
 {
        struct as_data *ad = q->elevator->elevator_data;
  */
 static void as_add_request(request_queue_t *q, struct request *rq)
 {
        struct as_data *ad = q->elevator->elevator_data;

-       struct as_rq *arq = RQ_DATA(rq);

        int data_dir;
 
        int data_dir;
 

-       arq->state = AS_RQ_NEW;
+       RQ_SET_STATE(rq, AS_RQ_NEW);

 
        data_dir = rq_is_sync(rq);
 
 
        data_dir = rq_is_sync(rq);
 

-       arq->io_context = as_get_io_context();
+       rq->elevator_private = as_get_io_context();

 
 

-       if (arq->io_context) {
-               as_update_iohist(ad, arq->io_context->aic, arq->request);
-               atomic_inc(&arq->io_context->aic->nr_queued);
+       if (RQ_IOC(rq)) {
+               as_update_iohist(ad, RQ_IOC(rq)->aic, rq);
+               atomic_inc(&RQ_IOC(rq)->aic->nr_queued);

        }
 
        }
 

-       as_add_arq_rb(ad, rq);
+       as_add_rq_rb(ad, rq);

 
        /*
         * set expire time (only used for reads) and add to fifo list
 
        /*
         * set expire time (only used for reads) and add to fifo list


@@ -1172,28 +1162,24 @@ static void as_add_request(request_queue_t *q, struct request *rq)
        rq_set_fifo_time(rq, jiffies + ad->fifo_expire[data_dir]);
        list_add_tail(&rq->queuelist, &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;
+       as_update_rq(ad, rq); /* keep state machine up to date */
+       RQ_SET_STATE(rq, AS_RQ_QUEUED);

 }
 
 static void as_activate_request(request_queue_t *q, struct request *rq)
 {
 }
 
 static void as_activate_request(request_queue_t *q, struct request *rq)
 {

-       struct as_rq *arq = RQ_DATA(rq);
-
-       WARN_ON(arq->state != AS_RQ_DISPATCHED);
-       arq->state = AS_RQ_REMOVED;
-       if (arq->io_context && arq->io_context->aic)
-               atomic_dec(&arq->io_context->aic->nr_dispatched);
+       WARN_ON(RQ_STATE(rq) != AS_RQ_DISPATCHED);
+       RQ_SET_STATE(rq, AS_RQ_REMOVED);
+       if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+               atomic_dec(&RQ_IOC(rq)->aic->nr_dispatched);

 }
 
 static void as_deactivate_request(request_queue_t *q, struct request *rq)
 {
 }
 
 static void as_deactivate_request(request_queue_t *q, struct request *rq)
 {

-       struct as_rq *arq = RQ_DATA(rq);
-
-       WARN_ON(arq->state != AS_RQ_REMOVED);
-       arq->state = AS_RQ_DISPATCHED;
-       if (arq->io_context && arq->io_context->aic)
-               atomic_inc(&arq->io_context->aic->nr_dispatched);
+       WARN_ON(RQ_STATE(rq) != AS_RQ_REMOVED);
+       RQ_SET_STATE(rq, AS_RQ_DISPATCHED);
+       if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+               atomic_inc(&RQ_IOC(rq)->aic->nr_dispatched);

 }
 
 /*
 }
 
 /*


@@ -1237,8 +1223,8 @@ static void as_merged_request(request_queue_t *q, struct request *req, int type)
         * if the merge was a front merge, we need to reposition request
         */
        if (type == ELEVATOR_FRONT_MERGE) {
         * if the merge was a front merge, we need to reposition request
         */
        if (type == ELEVATOR_FRONT_MERGE) {

-               as_del_arq_rb(ad, req);
-               as_add_arq_rb(ad, req);
+               as_del_rq_rb(ad, req);
+               as_add_rq_rb(ad, req);

                /*
                 * Note! At this stage of this and the next function, our next
                 * request may not be optimal - eg the request may have "grown"
                /*
                 * Note! At this stage of this and the next function, our next
                 * request may not be optimal - eg the request may have "grown"


@@ -1250,25 +1236,22 @@ static void as_merged_request(request_queue_t *q, struct request *req, int type)
 static void as_merged_requests(request_queue_t *q, struct request *req,
                                struct request *next)
 {
 static void as_merged_requests(request_queue_t *q, struct request *req,
                                struct request *next)
 {

-       struct as_rq *arq = RQ_DATA(req);
-       struct as_rq *anext = RQ_DATA(next);
-
-       BUG_ON(!arq);
-       BUG_ON(!anext);
-

        /*
        /*

-        * if anext expires before arq, assign its expire time to arq
-        * and move into anext position (anext will be deleted) in fifo
+        * if next expires before rq, assign its expire time to arq
+        * and move into next position (next will be deleted) in fifo

         */
        if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
                if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
         */
        if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
                if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {

+                       struct io_context *rioc = RQ_IOC(req);
+                       struct io_context *nioc = RQ_IOC(next);
+

                        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
                         */
                        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
                         */

-                       swap_io_context(&arq->io_context, &anext->io_context);
+                       swap_io_context(&rioc, &nioc);

                }
        }
 
                }
        }
 


@@ -1276,9 +1259,9 @@ static void as_merged_requests(request_queue_t *q, struct request *req,
         * kill knowledge of next, this one is a goner
         */
        as_remove_queued_request(q, next);
         * kill knowledge of next, this one is a goner
         */
        as_remove_queued_request(q, next);

-       as_put_io_context(anext);
+       as_put_io_context(next);

 
 

-       anext->state = AS_RQ_MERGED;
+       RQ_SET_STATE(next, AS_RQ_MERGED);

 }
 
 /*
 }
 
 /*


@@ -1301,45 +1284,6 @@ static void as_work_handler(void *data)
        spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
        spin_unlock_irqrestore(q->queue_lock, flags);
 }
 

-static void as_put_request(request_queue_t *q, struct request *rq)
-{
-       struct as_data *ad = q->elevator->elevator_data;
-       struct as_rq *arq = RQ_DATA(rq);
-
-       if (!arq) {
-               WARN_ON(1);
-               return;
-       }
-
-       if (unlikely(arq->state != AS_RQ_POSTSCHED &&
-                    arq->state != AS_RQ_PRESCHED &&
-                    arq->state != AS_RQ_MERGED)) {
-               printk("arq->state %d\n", arq->state);
-               WARN_ON(1);
-       }
-
-       mempool_free(arq, ad->arq_pool);
-       rq->elevator_private = NULL;
-}
-
-static int as_set_request(request_queue_t *q, struct request *rq,
-                         struct bio *bio, gfp_t gfp_mask)
-{
-       struct as_data *ad = q->elevator->elevator_data;
-       struct as_rq *arq = mempool_alloc(ad->arq_pool, gfp_mask);
-
-       if (arq) {
-               memset(arq, 0, sizeof(*arq));
-               arq->request = rq;
-               arq->state = AS_RQ_PRESCHED;
-               arq->io_context = NULL;
-               rq->elevator_private = arq;
-               return 0;
-       }
-
-       return 1;
-}
-

 static int as_may_queue(request_queue_t *q, int rw, struct bio *bio)
 {
        int ret = ELV_MQUEUE_MAY;
 static int as_may_queue(request_queue_t *q, int rw, struct bio *bio)
 {
        int ret = ELV_MQUEUE_MAY;


@@ -1366,22 +1310,17 @@ static void as_exit_queue(elevator_t *e)
        BUG_ON(!list_empty(&ad->fifo_list[REQ_SYNC]));
        BUG_ON(!list_empty(&ad->fifo_list[REQ_ASYNC]));
 
        BUG_ON(!list_empty(&ad->fifo_list[REQ_SYNC]));
        BUG_ON(!list_empty(&ad->fifo_list[REQ_ASYNC]));
 

-       mempool_destroy(ad->arq_pool);

        put_io_context(ad->io_context);
        kfree(ad);
 }
 
 /*
        put_io_context(ad->io_context);
        kfree(ad);
 }
 
 /*

- * initialize elevator private data (as_data), and alloc a arq for
- * each request on the free lists
+ * initialize elevator private data (as_data).

  */
 static void *as_init_queue(request_queue_t *q, elevator_t *e)
 {
        struct as_data *ad;
 
  */
 static void *as_init_queue(request_queue_t *q, elevator_t *e)
 {
        struct as_data *ad;
 

-       if (!arq_pool)
-               return NULL;
-

        ad = kmalloc_node(sizeof(*ad), GFP_KERNEL, q->node);
        if (!ad)
                return NULL;
        ad = kmalloc_node(sizeof(*ad), GFP_KERNEL, q->node);
        if (!ad)
                return NULL;


@@ -1389,13 +1328,6 @@ static void *as_init_queue(request_queue_t *q, elevator_t *e)
 
        ad->q = q; /* Identify what queue the data belongs to */
 
 
        ad->q = q; /* Identify what queue the data belongs to */
 

-       ad->arq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
-                               mempool_free_slab, arq_pool, q->node);
-       if (!ad->arq_pool) {
-               kfree(ad);
-               return NULL;
-       }
-

        /* anticipatory scheduling helpers */
        ad->antic_timer.function = as_antic_timeout;
        ad->antic_timer.data = (unsigned long)q;
        /* anticipatory scheduling helpers */
        ad->antic_timer.function = as_antic_timeout;
        ad->antic_timer.data = (unsigned long)q;


@@ -1516,8 +1448,6 @@ static struct elevator_type iosched_as = {
                .elevator_completed_req_fn =    as_completed_request,
                .elevator_former_req_fn =       elv_rb_former_request,
                .elevator_latter_req_fn =       elv_rb_latter_request,
                .elevator_completed_req_fn =    as_completed_request,
                .elevator_former_req_fn =       elv_rb_former_request,
                .elevator_latter_req_fn =       elv_rb_latter_request,

-               .elevator_set_req_fn =          as_set_request,
-               .elevator_put_req_fn =          as_put_request,

                .elevator_may_queue_fn =        as_may_queue,
                .elevator_init_fn =             as_init_queue,
                .elevator_exit_fn =             as_exit_queue,
                .elevator_may_queue_fn =        as_may_queue,
                .elevator_init_fn =             as_init_queue,
                .elevator_exit_fn =             as_exit_queue,


@@ -1533,11 +1463,6 @@ static int __init as_init(void)
 {
        int ret;
 
 {
        int ret;
 

-       arq_pool = kmem_cache_create("as_arq", sizeof(struct as_rq),
-                                    0, 0, NULL, NULL);
-       if (!arq_pool)
-               return -ENOMEM;
-

        ret = elv_register(&iosched_as);
        if (!ret) {
                /*
        ret = elv_register(&iosched_as);
        if (!ret) {
                /*


@@ -1549,7 +1474,6 @@ static int __init as_init(void)
                return 0;
        }
 
                return 0;
        }
 

-       kmem_cache_destroy(arq_pool);

        return ret;
 }
 
        return ret;
 }
 


@@ -1563,7 +1487,6 @@ static void __exit as_exit(void)
        if (atomic_read(&ioc_count))
                wait_for_completion(ioc_gone);
        synchronize_rcu();
        if (atomic_read(&ioc_count))
                wait_for_completion(ioc_gone);
        synchronize_rcu();

-       kmem_cache_destroy(arq_pool);

 }
 
 module_init(as_init);
 }
 
 module_init(as_init);