From a73f730d013ff2788389fd0c46ad3e5510f124e6 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 14 Dec 2011 00:33:37 +0100 Subject: [PATCH] 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 Signed-off-by: Jens Axboe --- block/blk-core.c | 24 ++++++++++++------- block/blk-sysfs.c | 2 ++ block/blk.h | 3 +++ block/cfq-iosched.c | 52 ++++-------------------------------------- include/linux/blkdev.h | 6 +++++ 5 files changed, 32 insertions(+), 55 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 30add45a87ef..af7301581172 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -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); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index f0b2ca8f66d0..5b4b4ab5e785 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -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); } diff --git a/block/blk.h b/block/blk.h index e38691dbb329..aae4d88fc523 100644 --- a/block/blk.h +++ b/block/blk.h @@ -1,6 +1,8 @@ #ifndef BLK_INTERNAL_H #define BLK_INTERNAL_H +#include + /* 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 16ace89613bc..ec3f5e8ba564 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(); } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 783f97c14d0a..8c8dbc4738ea 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -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 */