[BLOCK] ll_rw_blk: Enable out-of-order request completions through softirq

Request completion can be a quite heavy process, since it needs to iterate through the entire request and complete the bio's it holds. This patch adds blk_complete_request() which moves this processing into a dedicated block softirq.

Jens Axboe committed 20 years ago

Commit ff856ba1 parent 5367f2d3 files · +124 −4Browse files

Showing the changes to include (2 of 3 files). Show all

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2 files

include/linux/blkdev.h +18 −3
include/linux/interrupt.h +1 −0

include/linux/blkdev.h+18−3

@@ -118,9 +118,9 @@ struct request_list { · 117 unmodified lines
118	* try to put the fields that are referenced together in the same cacheline	118	* try to put the fields that are referenced together in the same cacheline
119	*/	119	*/
120	struct request {	120	struct request {
121	struct list_head queuelist; /* looking for ->queue? you must _not_	121	struct list_head queuelist;
122	* access it directly, use	122	struct list_head donelist;
123	* blkdev_dequeue_request! */	123
124	unsigned long flags; /* see REQ_ bits below */	124	unsigned long flags; /* see REQ_ bits below */
125		125
126	/* Maintain bio traversal state for part by part I/O submission.	126	/* Maintain bio traversal state for part by part I/O submission.
@@ -141,6 +141,7 @@ struct request { · 14 unmodified lines
141	struct bio *biotail;	141	struct bio *biotail;
142		142
143	void *elevator_private;	143	void *elevator_private;
		144	void *completion_data;
144		145
145	unsigned short ioprio;	146	unsigned short ioprio;
146		147
@@ -291,6 +292,7 @@ typedef int (merge_bvec_fn) (request_queue_t , struct bio , struct bio_vec *); · 144 unmodified lines
291	typedef void (activity_fn) (void *data, int rw);	292	typedef void (activity_fn) (void *data, int rw);
292	typedef int (issue_flush_fn) (request_queue_t , struct gendisk , sector_t *);	293	typedef int (issue_flush_fn) (request_queue_t , struct gendisk , sector_t *);
293	typedef void (prepare_flush_fn) (request_queue_t , struct request );	294	typedef void (prepare_flush_fn) (request_queue_t , struct request );
		295	typedef void (softirq_done_fn)(struct request *);
294		296
295	enum blk_queue_state {	297	enum blk_queue_state {
296	Queue_down,	298	Queue_down,
@@ -332,6 +334,7 @@ struct request_queue · 35 unmodified lines
332	activity_fn *activity_fn;	334	activity_fn *activity_fn;
333	issue_flush_fn *issue_flush_fn;	335	issue_flush_fn *issue_flush_fn;
334	prepare_flush_fn *prepare_flush_fn;	336	prepare_flush_fn *prepare_flush_fn;
		337	softirq_done_fn *softirq_done_fn;
335		338
336	/*	339	/*
337	* Dispatch queue sorting	340	* Dispatch queue sorting
@@ -646,6 +649,17 @@ extern int end_that_request_first(struct request *, int, int); · 308 unmodified lines
646	extern int end_that_request_chunk(struct request *, int, int);	649	extern int end_that_request_chunk(struct request *, int, int);
647	extern void end_that_request_last(struct request *, int);	650	extern void end_that_request_last(struct request *, int);
648	extern void end_request(struct request *req, int uptodate);	651	extern void end_request(struct request *req, int uptodate);
		652	extern void blk_complete_request(struct request *);
		653
		654	static inline int rq_all_done(struct request *rq, unsigned int nr_bytes)
		655	{
		656	if (blk_fs_request(rq))
		657	return (nr_bytes >= (rq->hard_nr_sectors << 9));
		658	else if (blk_pc_request(rq))
		659	return nr_bytes >= rq->data_len;
		660
		661	return 0;
		662	}
649		663
650	/*	664	/*
651	* end_that_request_first/chunk() takes an uptodate argument. we account	665	* 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); · 42 unmodified lines
694	extern void blk_queue_prep_rq(request_queue_t , prep_rq_fn pfn);	708	extern void blk_queue_prep_rq(request_queue_t , prep_rq_fn pfn);
695	extern void blk_queue_merge_bvec(request_queue_t , merge_bvec_fn );	709	extern void blk_queue_merge_bvec(request_queue_t , merge_bvec_fn );
696	extern void blk_queue_dma_alignment(request_queue_t *, int);	710	extern void blk_queue_dma_alignment(request_queue_t *, int);
		711	extern void blk_queue_softirq_done(request_queue_t , softirq_done_fn );
697	extern struct backing_dev_info blk_get_backing_dev_info(struct block_device bdev);	712	extern struct backing_dev_info blk_get_backing_dev_info(struct block_device bdev);
698	extern int blk_queue_ordered(request_queue_t , unsigned, prepare_flush_fn );	713	extern int blk_queue_ordered(request_queue_t , unsigned, prepare_flush_fn );
699	extern void blk_queue_issue_flush_fn(request_queue_t , issue_flush_fn );	714	extern void blk_queue_issue_flush_fn(request_queue_t , issue_flush_fn );

include/linux/interrupt.h+1−0

@@ -112,6 +112,7 @@ enum · 111 unmodified lines
112	TIMER_SOFTIRQ,	112	TIMER_SOFTIRQ,
113	NET_TX_SOFTIRQ,	113	NET_TX_SOFTIRQ,
114	NET_RX_SOFTIRQ,	114	NET_RX_SOFTIRQ,
		115	BLOCK_SOFTIRQ,
115	SCSI_SOFTIRQ,	116	SCSI_SOFTIRQ,
116	TASKLET_SOFTIRQ	117	TASKLET_SOFTIRQ
117	};	118	};