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authorTejun Heo <tj@kernel.org>2011-12-14 00:33:37 +0100
committerJens Axboe <axboe@kernel.dk>2011-12-14 00:33:37 +0100
commita73f730d013ff2788389fd0c46ad3e5510f124e6 (patch)
tree773987c8cbec56745d46f46382ad268ed91adf98 /block/cfq-iosched.c
parent8ba61435d73f2274e12d4d823fde06735e8f6a54 (diff)
block, cfq: move cfqd->cic_index to q->id
cfq allocates per-queue id using ida and uses it to index cic radix tree from io_context. Move it to q->id and allocate on queue init and free on queue release. This simplifies cfq a bit and will allow for further improvements of io context life-cycle management. This patch 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/cfq-iosched.c')
-rw-r--r--block/cfq-iosched.c52
1 files changed, 5 insertions, 47 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 16ace89613b..ec3f5e8ba56 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -65,9 +65,6 @@ static DEFINE_PER_CPU(unsigned long, cfq_ioc_count);
static struct completion *ioc_gone;
static DEFINE_SPINLOCK(ioc_gone_lock);
-static DEFINE_SPINLOCK(cic_index_lock);
-static DEFINE_IDA(cic_index_ida);
-
#define CFQ_PRIO_LISTS IOPRIO_BE_NR
#define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
#define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT)
@@ -290,7 +287,6 @@ struct cfq_data {
unsigned int cfq_group_idle;
unsigned int cfq_latency;
- unsigned int cic_index;
struct list_head cic_list;
/*
@@ -484,7 +480,7 @@ static inline void cic_set_cfqq(struct cfq_io_context *cic,
static inline void *cfqd_dead_key(struct cfq_data *cfqd)
{
- return (void *)(cfqd->cic_index << CIC_DEAD_INDEX_SHIFT | CIC_DEAD_KEY);
+ return (void *)(cfqd->queue->id << CIC_DEAD_INDEX_SHIFT | CIC_DEAD_KEY);
}
static inline struct cfq_data *cic_to_cfqd(struct cfq_io_context *cic)
@@ -3105,7 +3101,7 @@ cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc,
BUG_ON(rcu_dereference_check(ioc->ioc_data,
lockdep_is_held(&ioc->lock)) == cic);
- radix_tree_delete(&ioc->radix_root, cfqd->cic_index);
+ radix_tree_delete(&ioc->radix_root, cfqd->queue->id);
hlist_del_rcu(&cic->cic_list);
spin_unlock_irqrestore(&ioc->lock, flags);
@@ -3133,7 +3129,7 @@ cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc)
}
do {
- cic = radix_tree_lookup(&ioc->radix_root, cfqd->cic_index);
+ cic = radix_tree_lookup(&ioc->radix_root, cfqd->queue->id);
rcu_read_unlock();
if (!cic)
break;
@@ -3169,8 +3165,7 @@ static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc,
cic->key = cfqd;
spin_lock_irqsave(&ioc->lock, flags);
- ret = radix_tree_insert(&ioc->radix_root,
- cfqd->cic_index, cic);
+ ret = radix_tree_insert(&ioc->radix_root, cfqd->queue->id, cic);
if (!ret)
hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list);
spin_unlock_irqrestore(&ioc->lock, flags);
@@ -3944,10 +3939,6 @@ static void cfq_exit_queue(struct elevator_queue *e)
cfq_shutdown_timer_wq(cfqd);
- spin_lock(&cic_index_lock);
- ida_remove(&cic_index_ida, cfqd->cic_index);
- spin_unlock(&cic_index_lock);
-
/*
* Wait for cfqg->blkg->key accessors to exit their grace periods.
* Do this wait only if there are other unlinked groups out
@@ -3969,24 +3960,6 @@ static void cfq_exit_queue(struct elevator_queue *e)
kfree(cfqd);
}
-static int cfq_alloc_cic_index(void)
-{
- int index, error;
-
- do {
- if (!ida_pre_get(&cic_index_ida, GFP_KERNEL))
- return -ENOMEM;
-
- spin_lock(&cic_index_lock);
- error = ida_get_new(&cic_index_ida, &index);
- spin_unlock(&cic_index_lock);
- if (error && error != -EAGAIN)
- return error;
- } while (error);
-
- return index;
-}
-
static void *cfq_init_queue(struct request_queue *q)
{
struct cfq_data *cfqd;
@@ -3994,23 +3967,9 @@ static void *cfq_init_queue(struct request_queue *q)
struct cfq_group *cfqg;
struct cfq_rb_root *st;
- i = cfq_alloc_cic_index();
- if (i < 0)
- return NULL;
-
cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);
- if (!cfqd) {
- spin_lock(&cic_index_lock);
- ida_remove(&cic_index_ida, i);
- spin_unlock(&cic_index_lock);
+ if (!cfqd)
return NULL;
- }
-
- /*
- * Don't need take queue_lock in the routine, since we are
- * initializing the ioscheduler, and nobody is using cfqd
- */
- cfqd->cic_index = i;
/* Init root service tree */
cfqd->grp_service_tree = CFQ_RB_ROOT;
@@ -4294,7 +4253,6 @@ static void __exit cfq_exit(void)
*/
if (elv_ioc_count_read(cfq_ioc_count))
wait_for_completion(&all_gone);
- ida_destroy(&cic_index_ida);
cfq_slab_kill();
}