[PATCH] keep sync and async cfq_queue separate

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 42f990f..63bfe4b 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1219,11 +1219,20 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic)
 
        spin_lock(q->queue_lock);
 
-       if (unlikely(cic->cfqq == cfqd->active_queue))
-               __cfq_slice_expired(cfqd, cic->cfqq, 0);
+       if (cic->cfqq[ASYNC]) {
+               if (unlikely(cic->cfqq[ASYNC] == cfqd->active_queue))
+                       __cfq_slice_expired(cfqd, cic->cfqq[ASYNC], 0);
+               cfq_put_queue(cic->cfqq[ASYNC]);
+               cic->cfqq[ASYNC] = NULL;
+       }
+
+       if (cic->cfqq[SYNC]) {
+               if (unlikely(cic->cfqq[SYNC] == cfqd->active_queue))
+                       __cfq_slice_expired(cfqd, cic->cfqq[SYNC], 0);
+               cfq_put_queue(cic->cfqq[SYNC]);
+               cic->cfqq[SYNC] = NULL;
+       }
 
-       cfq_put_queue(cic->cfqq);
-       cic->cfqq = NULL;
        cic->key = NULL;
        spin_unlock(q->queue_lock);
 }
@@ -1259,7 +1268,8 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
 
        if (cic) {
                INIT_LIST_HEAD(&cic->list);
-               cic->cfqq = NULL;
+               cic->cfqq[ASYNC] = NULL;
+               cic->cfqq[SYNC] = NULL;
                cic->key = NULL;
                cic->last_end_request = jiffies;
                cic->ttime_total = 0;
@@ -1325,7 +1335,12 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
        struct cfq_queue *cfqq;
        if (cfqd) {
                spin_lock(cfqd->queue->queue_lock);
-               cfqq = cic->cfqq;
+               cfqq = cic->cfqq[ASYNC];
+               if (cfqq) {
+                       cfq_mark_cfqq_prio_changed(cfqq);
+                       cfq_init_prio_data(cfqq);
+               }
+               cfqq = cic->cfqq[SYNC];
                if (cfqq) {
                        cfq_mark_cfqq_prio_changed(cfqq);
                        cfq_init_prio_data(cfqq);
@@ -1892,6 +1907,7 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
        struct cfq_queue *cfqq;
        struct cfq_rq *crq;
        unsigned long flags;
+       int is_sync = key != CFQ_KEY_ASYNC;
 
        might_sleep_if(gfp_mask & __GFP_WAIT);
 
@@ -1902,14 +1918,14 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
        if (!cic)
                goto queue_fail;
 
-       if (!cic->cfqq) {
+       if (!cic->cfqq[is_sync]) {
                cfqq = cfq_get_queue(cfqd, key, tsk->ioprio, gfp_mask);
                if (!cfqq)
                        goto queue_fail;
 
-               cic->cfqq = cfqq;
+               cic->cfqq[is_sync] = cfqq;
        } else
-               cfqq = cic->cfqq;
+               cfqq = cic->cfqq[is_sync];
 
        cfqq->allocated[rw]++;
        cfq_clear_cfqq_must_alloc(cfqq);
@@ -1926,7 +1942,7 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
                crq->cfq_queue = cfqq;
                crq->io_context = cic;
 
-               if (rw == READ || process_sync(tsk))
+               if (is_sync)
                        cfq_mark_crq_is_sync(crq);
                else
                        cfq_clear_crq_is_sync(crq);

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 860e7a4..e19cb63 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -58,7 +58,7 @@ struct cfq_io_context {
         * circular list of cfq_io_contexts belonging to a process io context
         */
        struct list_head list;
-       struct cfq_queue *cfqq;
+       struct cfq_queue *cfqq[2];
        void *key;
 
        struct io_context *ioc;