cfq-iosched: make io priorities inherit CPU scheduling class as well as nice

[linux-2.6-omap-h63xx.git] / block / cfq-iosched.c

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index f26da2bfcc15714e0bbc10734aff7a91dae446ac..b399c62936e01a503715273ffef29ac2fafef8a4 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1142,6 +1142,17 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
        kmem_cache_free(cfq_pool, cfqq);
 }
 
+static void
+__call_for_each_cic(struct io_context *ioc,
+                   void (*func)(struct io_context *, struct cfq_io_context *))
+{
+       struct cfq_io_context *cic;
+       struct hlist_node *n;
+
+       hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list)
+               func(ioc, cic);
+}
+
 /*
  * Call func for each cic attached to this ioc.
  */
@@ -1149,12 +1160,8 @@ static void
 call_for_each_cic(struct io_context *ioc,
                  void (*func)(struct io_context *, struct cfq_io_context *))
 {
-       struct cfq_io_context *cic;
-       struct hlist_node *n;
-
        rcu_read_lock();
-       hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list)
-               func(ioc, cic);
+       __call_for_each_cic(ioc, func);
        rcu_read_unlock();
 }
 
@@ -1198,7 +1205,7 @@ static void cfq_free_io_context(struct io_context *ioc)
         * should be ok to iterate over the known list, we will see all cic's
         * since no new ones are added.
         */
-       call_for_each_cic(ioc, cic_free_func);
+       __call_for_each_cic(ioc, cic_free_func);
 }
 
 static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
@@ -1214,6 +1221,8 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
                                         struct cfq_io_context *cic)
 {
+       struct io_context *ioc = cic->ioc;
+
        list_del_init(&cic->queue_list);
 
        /*
@@ -1223,6 +1232,9 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
        cic->dead_key = (unsigned long) cic->key;
        cic->key = NULL;
 
+       if (ioc->ioc_data == cic)
+               rcu_assign_pointer(ioc->ioc_data, NULL);
+
        if (cic->cfqq[ASYNC]) {
                cfq_exit_cfqq(cfqd, cic->cfqq[ASYNC]);
                cic->cfqq[ASYNC] = NULL;
@@ -1255,7 +1267,6 @@ static void cfq_exit_single_io_context(struct io_context *ioc,
  */
 static void cfq_exit_io_context(struct io_context *ioc)
 {
-       rcu_assign_pointer(ioc->ioc_data, NULL);
        call_for_each_cic(ioc, cfq_exit_single_io_context);
 }
 
@@ -1292,10 +1303,10 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
                printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
        case IOPRIO_CLASS_NONE:
                /*
-                * no prio set, place us in the middle of the BE classes
+                * no prio set, inherit CPU scheduling settings
                 */
                cfqq->ioprio = task_nice_ioprio(tsk);
-               cfqq->ioprio_class = IOPRIO_CLASS_BE;
+               cfqq->ioprio_class = task_nice_ioclass(tsk);
                break;
        case IOPRIO_CLASS_RT:
                cfqq->ioprio = task_ioprio(ioc);
@@ -1478,8 +1489,7 @@ cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc,
 
        spin_lock_irqsave(&ioc->lock, flags);
 
-       if (ioc->ioc_data == cic)
-               rcu_assign_pointer(ioc->ioc_data, NULL);
+       BUG_ON(ioc->ioc_data == cic);
 
        radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd);
        hlist_del_rcu(&cic->cic_list);