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>
diff --git a/block/blk-core.c b/block/blk-core.c
index 30add45..af73015 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -39,6 +39,8 @@
EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
+DEFINE_IDA(blk_queue_ida);
+
/*
* For the allocated request tables
*/
@@ -474,6 +476,10 @@
if (!q)
return NULL;
+ q->id = ida_simple_get(&blk_queue_ida, 0, 0, GFP_KERNEL);
+ if (q->id < 0)
+ goto fail_q;
+
q->backing_dev_info.ra_pages =
(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.state = 0;
@@ -481,15 +487,11 @@
q->backing_dev_info.name = "block";
err = bdi_init(&q->backing_dev_info);
- if (err) {
- kmem_cache_free(blk_requestq_cachep, q);
- return NULL;
- }
+ if (err)
+ goto fail_id;
- if (blk_throtl_init(q)) {
- kmem_cache_free(blk_requestq_cachep, q);
- return NULL;
- }
+ if (blk_throtl_init(q))
+ goto fail_id;
setup_timer(&q->backing_dev_info.laptop_mode_wb_timer,
laptop_mode_timer_fn, (unsigned long) q);
@@ -512,6 +514,12 @@
q->queue_lock = &q->__queue_lock;
return q;
+
+fail_id:
+ ida_simple_remove(&blk_queue_ida, q->id);
+fail_q:
+ kmem_cache_free(blk_requestq_cachep, q);
+ return NULL;
}
EXPORT_SYMBOL(blk_alloc_queue_node);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index f0b2ca8..5b4b4ab 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -494,6 +494,8 @@
blk_trace_shutdown(q);
bdi_destroy(&q->backing_dev_info);
+
+ ida_simple_remove(&blk_queue_ida, q->id);
kmem_cache_free(blk_requestq_cachep, q);
}
diff --git a/block/blk.h b/block/blk.h
index e38691d..aae4d88 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -1,6 +1,8 @@
#ifndef BLK_INTERNAL_H
#define BLK_INTERNAL_H
+#include <linux/idr.h>
+
/* Amount of time in which a process may batch requests */
#define BLK_BATCH_TIME (HZ/50UL)
@@ -9,6 +11,7 @@
extern struct kmem_cache *blk_requestq_cachep;
extern struct kobj_type blk_queue_ktype;
+extern struct ida blk_queue_ida;
void init_request_from_bio(struct request *req, struct bio *bio);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 16ace89..ec3f5e8b 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -65,9 +65,6 @@
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 @@
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 *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 @@
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 @@
}
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 @@
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 @@
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 @@
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 @@
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 @@
*/
if (elv_ioc_count_read(cfq_ioc_count))
wait_for_completion(&all_gone);
- ida_destroy(&cic_index_ida);
cfq_slab_kill();
}