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>
This commit is contained in:
Tejun Heo 2011-12-14 00:33:37 +01:00 committed by Jens Axboe
parent 8ba61435d7
commit a73f730d01
5 changed files with 32 additions and 55 deletions

View File

@ -39,6 +39,8 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
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 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
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 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
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 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
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);

View File

@ -494,6 +494,8 @@ static void blk_release_queue(struct kobject *kobj)
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);
}

View File

@ -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,

View File

@ -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();
}

View File

@ -310,6 +310,12 @@ struct request_queue {
*/
unsigned long queue_flags;
/*
* ida allocated id for this queue. Used to index queues from
* ioctx.
*/
int id;
/*
* queue needs bounce pages for pages above this limit
*/