X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=block%2Fcfq-iosched.c;h=b399c62936e01a503715273ffef29ac2fafef8a4;hb=e6da97e7df385a1674cf9f72c31b7a0e46e2620d;hp=0f962ecae91fb68345fe1d916791a78e06a2f2e8;hpb=f8303dd3db57bd7ab2062985ad7a9e898a8ac423;p=linux-2.6-omap-h63xx.git

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 0f962ecae91..b399c62936e 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1142,25 +1142,45 @@ 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. Returns number of cic's seen.
+ * Call func for each cic attached to this ioc.
  */
-static unsigned int
+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;
-	int called = 0;
-
 	rcu_read_lock();
-	hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) {
-		func(ioc, cic);
-		called++;
-	}
+	__call_for_each_cic(ioc, func);
 	rcu_read_unlock();
+}
 
-	return called;
+static void cfq_cic_free_rcu(struct rcu_head *head)
+{
+	struct cfq_io_context *cic;
+
+	cic = container_of(head, struct cfq_io_context, rcu_head);
+
+	kmem_cache_free(cfq_ioc_pool, cic);
+	elv_ioc_count_dec(ioc_count);
+
+	if (ioc_gone && !elv_ioc_count_read(ioc_count))
+		complete(ioc_gone);
+}
+
+static void cfq_cic_free(struct cfq_io_context *cic)
+{
+	call_rcu(&cic->rcu_head, cfq_cic_free_rcu);
 }
 
 static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic)
@@ -1174,24 +1194,18 @@ static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic)
 	hlist_del_rcu(&cic->cic_list);
 	spin_unlock_irqrestore(&ioc->lock, flags);
 
-	kmem_cache_free(cfq_ioc_pool, cic);
+	cfq_cic_free(cic);
 }
 
 static void cfq_free_io_context(struct io_context *ioc)
 {
-	int freed;
-
 	/*
-	 * ioc->refcount is zero here, so no more cic's are allowed to be
-	 * linked into this ioc. So it should be ok to iterate over the known
-	 * list, we will see all cic's since no new ones are added.
+	 * ioc->refcount is zero here, or we are called from elv_unregister(),
+	 * so no more cic's are allowed to be linked into this ioc.  So it
+	 * should be ok to iterate over the known list, we will see all cic's
+	 * since no new ones are added.
 	 */
-	freed = call_for_each_cic(ioc, cic_free_func);
-
-	elv_ioc_count_mod(ioc_count, -freed);
-
-	if (ioc_gone && !elv_ioc_count_read(ioc_count))
-		complete(ioc_gone);
+	__call_for_each_cic(ioc, cic_free_func);
 }
 
 static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
@@ -1207,6 +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);
 
 	/*
@@ -1216,6 +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;
@@ -1248,7 +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);
 }
 
@@ -1285,10 +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);
@@ -1458,15 +1476,6 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct io_context *ioc,
 	return cfqq;
 }
 
-static void cfq_cic_free(struct cfq_io_context *cic)
-{
-	kmem_cache_free(cfq_ioc_pool, cic);
-	elv_ioc_count_dec(ioc_count);
-
-	if (ioc_gone && !elv_ioc_count_read(ioc_count))
-		complete(ioc_gone);
-}
-
 /*
  * We drop cfq io contexts lazily, so we may find a dead one.
  */
@@ -1480,8 +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);
@@ -2138,7 +2146,7 @@ static int __init cfq_slab_setup(void)
 	if (!cfq_pool)
 		goto fail;
 
-	cfq_ioc_pool = KMEM_CACHE(cfq_io_context, SLAB_DESTROY_BY_RCU);
+	cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0);
 	if (!cfq_ioc_pool)
 		goto fail;
 
@@ -2286,7 +2294,6 @@ static void __exit cfq_exit(void)
 	smp_wmb();
 	if (elv_ioc_count_read(ioc_count))
 		wait_for_completion(ioc_gone);
-	synchronize_rcu();
 	cfq_slab_kill();
 }