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authorTejun Heo <tj@kernel.org>2011-12-14 00:33:42 +0100
committerJens Axboe <axboe@kernel.dk>2011-12-14 00:33:42 +0100
commit9b84cacd013996f244d85b3d873287c2a8f88658 (patch)
treea11b850f9c8b182a7a8141276244a831aaae5291 /block
parent7e5a8794492e43e9eebb68a98a23be055888ccd0 (diff)
downloadlinux-9b84cacd013996f244d85b3d873287c2a8f88658.tar.bz2
block, cfq: restructure io_cq creation path for io_context interface cleanup
Add elevator_ops->elevator_init_icq_fn() and restructure cfq_create_cic() and rename it to ioc_create_icq(). The new function expects its caller to pass in io_context, uses elevator_type->icq_cache, handles generic init, calls the new elevator operation for elevator specific initialization, and returns pointer to created or looked up icq. This leaves cfq_icq_pool variable without any user. Removed. This prepares for io_context interface cleanup and doesn't introduce any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/cfq-iosched.c94
1 files changed, 41 insertions, 53 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index f6d315551496..11f49d036845 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -59,7 +59,6 @@ static const int cfq_hist_divisor = 4;
#define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elv.priv[1])
static struct kmem_cache *cfq_pool;
-static struct kmem_cache *cfq_icq_pool;
#define CFQ_PRIO_LISTS IOPRIO_BE_NR
#define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
@@ -2707,6 +2706,13 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
cfq_put_queue(cfqq);
}
+static void cfq_init_icq(struct io_cq *icq)
+{
+ struct cfq_io_cq *cic = icq_to_cic(icq);
+
+ cic->ttime.last_end_request = jiffies;
+}
+
static void cfq_exit_icq(struct io_cq *icq)
{
struct cfq_io_cq *cic = icq_to_cic(icq);
@@ -2723,21 +2729,6 @@ static void cfq_exit_icq(struct io_cq *icq)
}
}
-static struct cfq_io_cq *cfq_alloc_cic(struct cfq_data *cfqd, gfp_t gfp_mask)
-{
- struct cfq_io_cq *cic;
-
- cic = kmem_cache_alloc_node(cfq_icq_pool, gfp_mask | __GFP_ZERO,
- cfqd->queue->node);
- if (cic) {
- cic->ttime.last_end_request = jiffies;
- INIT_LIST_HEAD(&cic->icq.q_node);
- INIT_HLIST_NODE(&cic->icq.ioc_node);
- }
-
- return cic;
-}
-
static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
{
struct task_struct *tsk = current;
@@ -2945,64 +2936,62 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc,
}
/**
- * cfq_create_cic - create and link a cfq_io_cq
- * @cfqd: cfqd of interest
+ * ioc_create_icq - create and link io_cq
+ * @q: request_queue of interest
* @gfp_mask: allocation mask
*
- * Make sure cfq_io_cq linking %current->io_context and @cfqd exists. If
- * ioc and/or cic doesn't exist, they will be created using @gfp_mask.
+ * Make sure io_cq linking %current->io_context and @q exists. If either
+ * io_context and/or icq don't exist, they will be created using @gfp_mask.
+ *
+ * The caller is responsible for ensuring @ioc won't go away and @q is
+ * alive and will stay alive until this function returns.
*/
-static int cfq_create_cic(struct cfq_data *cfqd, gfp_t gfp_mask)
+static struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask)
{
- struct request_queue *q = cfqd->queue;
- struct io_cq *icq = NULL;
- struct cfq_io_cq *cic;
+ struct elevator_type *et = q->elevator->type;
struct io_context *ioc;
- int ret = -ENOMEM;
-
- might_sleep_if(gfp_mask & __GFP_WAIT);
+ struct io_cq *icq;
/* allocate stuff */
ioc = create_io_context(current, gfp_mask, q->node);
if (!ioc)
- goto out;
+ return NULL;
- cic = cfq_alloc_cic(cfqd, gfp_mask);
- if (!cic)
- goto out;
- icq = &cic->icq;
+ icq = kmem_cache_alloc_node(et->icq_cache, gfp_mask | __GFP_ZERO,
+ q->node);
+ if (!icq)
+ return NULL;
- ret = radix_tree_preload(gfp_mask);
- if (ret)
- goto out;
+ if (radix_tree_preload(gfp_mask) < 0) {
+ kmem_cache_free(et->icq_cache, icq);
+ return NULL;
+ }
icq->ioc = ioc;
- icq->q = cfqd->queue;
+ icq->q = q;
+ INIT_LIST_HEAD(&icq->q_node);
+ INIT_HLIST_NODE(&icq->ioc_node);
/* lock both q and ioc and try to link @icq */
spin_lock_irq(q->queue_lock);
spin_lock(&ioc->lock);
- ret = radix_tree_insert(&ioc->icq_tree, q->id, icq);
- if (likely(!ret)) {
+ if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) {
hlist_add_head(&icq->ioc_node, &ioc->icq_list);
list_add(&icq->q_node, &q->icq_list);
- icq = NULL;
- } else if (ret == -EEXIST) {
- /* someone else already did it */
- ret = 0;
+ if (et->ops.elevator_init_icq_fn)
+ et->ops.elevator_init_icq_fn(icq);
+ } else {
+ kmem_cache_free(et->icq_cache, icq);
+ icq = ioc_lookup_icq(ioc, q);
+ if (!icq)
+ printk(KERN_ERR "cfq: icq link failed!\n");
}
spin_unlock(&ioc->lock);
spin_unlock_irq(q->queue_lock);
-
radix_tree_preload_end();
-out:
- if (ret)
- printk(KERN_ERR "cfq: icq link failed!\n");
- if (icq)
- kmem_cache_free(cfq_icq_pool, icq);
- return ret;
+ return icq;
}
/**
@@ -3022,7 +3011,6 @@ static struct cfq_io_cq *cfq_get_cic(struct cfq_data *cfqd, gfp_t gfp_mask)
struct request_queue *q = cfqd->queue;
struct cfq_io_cq *cic = NULL;
struct io_context *ioc;
- int err;
lockdep_assert_held(q->queue_lock);
@@ -3037,9 +3025,9 @@ static struct cfq_io_cq *cfq_get_cic(struct cfq_data *cfqd, gfp_t gfp_mask)
/* slow path - unlock, create missing ones and retry */
spin_unlock_irq(q->queue_lock);
- err = cfq_create_cic(cfqd, gfp_mask);
+ cic = icq_to_cic(ioc_create_icq(q, gfp_mask));
spin_lock_irq(q->queue_lock);
- if (err)
+ if (!cic)
return NULL;
}
@@ -3975,6 +3963,7 @@ static struct elevator_type iosched_cfq = {
.elevator_completed_req_fn = cfq_completed_request,
.elevator_former_req_fn = elv_rb_former_request,
.elevator_latter_req_fn = elv_rb_latter_request,
+ .elevator_init_icq_fn = cfq_init_icq,
.elevator_exit_icq_fn = cfq_exit_icq,
.elevator_set_req_fn = cfq_set_request,
.elevator_put_req_fn = cfq_put_request,
@@ -4028,7 +4017,6 @@ static int __init cfq_init(void)
kmem_cache_destroy(cfq_pool);
return ret;
}
- cfq_icq_pool = iosched_cfq.icq_cache;
blkio_policy_register(&blkio_policy_cfq);