diff options
| -rw-r--r-- | block/ll_rw_blk.c | 106 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 21 | ||||
| -rw-r--r-- | include/linux/interrupt.h | 1 |
3 files changed, 124 insertions, 4 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 91d3b4828c4..8e136450abc 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -27,6 +27,8 @@ #include <linux/swap.h> #include <linux/writeback.h> #include <linux/blkdev.h> +#include <linux/interrupt.h> +#include <linux/cpu.h> /* * for max sense size @@ -62,13 +64,15 @@ static wait_queue_head_t congestion_wqh[2] = { /* * Controlling structure to kblockd */ -static struct workqueue_struct *kblockd_workqueue; +static struct workqueue_struct *kblockd_workqueue; unsigned long blk_max_low_pfn, blk_max_pfn; EXPORT_SYMBOL(blk_max_low_pfn); EXPORT_SYMBOL(blk_max_pfn); +static DEFINE_PER_CPU(struct list_head, blk_cpu_done); + /* Amount of time in which a process may batch requests */ #define BLK_BATCH_TIME (HZ/50UL) @@ -207,6 +211,13 @@ void blk_queue_merge_bvec(request_queue_t *q, merge_bvec_fn *mbfn) EXPORT_SYMBOL(blk_queue_merge_bvec); +void blk_queue_softirq_done(request_queue_t *q, softirq_done_fn *fn) +{ + q->softirq_done_fn = fn; +} + +EXPORT_SYMBOL(blk_queue_softirq_done); + /** * blk_queue_make_request - define an alternate make_request function for a device * @q: the request queue for the device to be affected @@ -270,6 +281,7 @@ EXPORT_SYMBOL(blk_queue_make_request); static inline void rq_init(request_queue_t *q, struct request *rq) { INIT_LIST_HEAD(&rq->queuelist); + INIT_LIST_HEAD(&rq->donelist); rq->errors = 0; rq->rq_status = RQ_ACTIVE; @@ -286,6 +298,7 @@ static inline void rq_init(request_queue_t *q, struct request *rq) rq->sense = NULL; rq->end_io = NULL; rq->end_io_data = NULL; + rq->completion_data = NULL; } /** @@ -3287,6 +3300,87 @@ int end_that_request_chunk(struct request *req, int uptodate, int nr_bytes) EXPORT_SYMBOL(end_that_request_chunk); /* + * splice the completion data to a local structure and hand off to + * process_completion_queue() to complete the requests + */ +static void blk_done_softirq(struct softirq_action *h) +{ + struct list_head *cpu_list; + LIST_HEAD(local_list); + + local_irq_disable(); + cpu_list = &__get_cpu_var(blk_cpu_done); + list_splice_init(cpu_list, &local_list); + local_irq_enable(); + + while (!list_empty(&local_list)) { + struct request *rq = list_entry(local_list.next, struct request, donelist); + + list_del_init(&rq->donelist); + rq->q->softirq_done_fn(rq); + } +} + +#ifdef CONFIG_HOTPLUG_CPU + +static int blk_cpu_notify(struct notifier_block *self, unsigned long action, + void *hcpu) +{ + /* + * If a CPU goes away, splice its entries to the current CPU + * and trigger a run of the softirq + */ + if (action == CPU_DEAD) { + int cpu = (unsigned long) hcpu; + + local_irq_disable(); + list_splice_init(&per_cpu(blk_cpu_done, cpu), + &__get_cpu_var(blk_cpu_done)); + raise_softirq_irqoff(BLOCK_SOFTIRQ); + local_irq_enable(); + } + + return NOTIFY_OK; +} + + +static struct notifier_block __devinitdata blk_cpu_notifier = { + .notifier_call = blk_cpu_notify, +}; + +#endif /* CONFIG_HOTPLUG_CPU */ + +/** + * blk_complete_request - end I/O on a request + * @req: the request being processed + * + * Description: + * Ends all I/O on a request. It does not handle partial completions, + * unless the driver actually implements this in its completionc callback + * through requeueing. Theh actual completion happens out-of-order, + * through a softirq handler. The user must have registered a completion + * callback through blk_queue_softirq_done(). + **/ + +void blk_complete_request(struct request *req) +{ + struct list_head *cpu_list; + unsigned long flags; + + BUG_ON(!req->q->softirq_done_fn); + + local_irq_save(flags); + + cpu_list = &__get_cpu_var(blk_cpu_done); + list_add_tail(&req->donelist, cpu_list); + raise_softirq_irqoff(BLOCK_SOFTIRQ); + + local_irq_restore(flags); +} + +EXPORT_SYMBOL(blk_complete_request); + +/* * queue lock must be held */ void end_that_request_last(struct request *req, int uptodate) @@ -3364,6 +3458,8 @@ EXPORT_SYMBOL(kblockd_flush); int __init blk_dev_init(void) { + int i; + kblockd_workqueue = create_workqueue("kblockd"); if (!kblockd_workqueue) panic("Failed to create kblockd\n"); @@ -3377,6 +3473,14 @@ int __init blk_dev_init(void) iocontext_cachep = kmem_cache_create("blkdev_ioc", sizeof(struct io_context), 0, SLAB_PANIC, NULL, NULL); + for (i = 0; i < NR_CPUS; i++) + INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); + + open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); +#ifdef CONFIG_HOTPLUG_CPU + register_cpu_notifier(&blk_cpu_notifier); +#endif + blk_max_low_pfn = max_low_pfn; blk_max_pfn = max_pfn; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index fb098537742..804cc4ec953 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -118,9 +118,9 @@ struct request_list { * try to put the fields that are referenced together in the same cacheline */ struct request { - struct list_head queuelist; /* looking for ->queue? you must _not_ - * access it directly, use - * blkdev_dequeue_request! */ + struct list_head queuelist; + struct list_head donelist; + unsigned long flags; /* see REQ_ bits below */ /* Maintain bio traversal state for part by part I/O submission. @@ -141,6 +141,7 @@ struct request { struct bio *biotail; void *elevator_private; + void *completion_data; unsigned short ioprio; @@ -291,6 +292,7 @@ typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); typedef void (activity_fn) (void *data, int rw); typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); typedef void (prepare_flush_fn) (request_queue_t *, struct request *); +typedef void (softirq_done_fn)(struct request *); enum blk_queue_state { Queue_down, @@ -332,6 +334,7 @@ struct request_queue activity_fn *activity_fn; issue_flush_fn *issue_flush_fn; prepare_flush_fn *prepare_flush_fn; + softirq_done_fn *softirq_done_fn; /* * Dispatch queue sorting @@ -646,6 +649,17 @@ extern int end_that_request_first(struct request *, int, int); extern int end_that_request_chunk(struct request *, int, int); extern void end_that_request_last(struct request *, int); extern void end_request(struct request *req, int uptodate); +extern void blk_complete_request(struct request *); + +static inline int rq_all_done(struct request *rq, unsigned int nr_bytes) +{ + if (blk_fs_request(rq)) + return (nr_bytes >= (rq->hard_nr_sectors << 9)); + else if (blk_pc_request(rq)) + return nr_bytes >= rq->data_len; + + return 0; +} /* * end_that_request_first/chunk() takes an uptodate argument. we account @@ -694,6 +708,7 @@ extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); extern void blk_queue_dma_alignment(request_queue_t *, int); +extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *); extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index e50a95fbeb1..f0220470698 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -112,6 +112,7 @@ enum TIMER_SOFTIRQ, NET_TX_SOFTIRQ, NET_RX_SOFTIRQ, + BLOCK_SOFTIRQ, SCSI_SOFTIRQ, TASKLET_SOFTIRQ }; |