Commit b8b3e16c authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Jens Axboe
Browse files

block: drop virtual merging accounting 



Remove virtual merge accounting.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 6a421c1d

block/blk-merge.c

+6 −73
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ void blk_recalc_rq_segments(struct request *rq) 
		 */

		high = page_to_pfn(bv->bv_page) > q->bounce_pfn;

		if (high || highprv)

			goto new_hw_segment;

			goto new_segment;

		if (cluster) {

			if (seg_size + bv->bv_len > q->max_segment_size)

				goto new_segment;
@@ -74,8 +74,6 @@ void blk_recalc_rq_segments(struct request *rq) 
				goto new_segment;

			if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))

				goto new_segment;

			if (BIOVEC_VIRT_OVERSIZE(hw_seg_size + bv->bv_len))

				goto new_hw_segment;



			seg_size += bv->bv_len;

			hw_seg_size += bv->bv_len;
@@ -83,17 +81,11 @@ void blk_recalc_rq_segments(struct request *rq) 
			continue;

		}

new_segment:

		if (BIOVEC_VIRT_MERGEABLE(bvprv, bv) &&

		    !BIOVEC_VIRT_OVERSIZE(hw_seg_size + bv->bv_len))

			hw_seg_size += bv->bv_len;

		else {

new_hw_segment:

		if (nr_hw_segs == 1 &&

		    hw_seg_size > rq->bio->bi_hw_front_size)

			rq->bio->bi_hw_front_size = hw_seg_size;

			hw_seg_size = BIOVEC_VIRT_START_SIZE(bv) + bv->bv_len;

		hw_seg_size = bv->bv_len;

		nr_hw_segs++;

		}



		nr_phys_segs++;

		bvprv = bv;
@@ -150,23 +142,6 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio, 
	return 0;

}



static int blk_hw_contig_segment(struct request_queue *q, struct bio *bio,

				 struct bio *nxt)

{

	if (!bio_flagged(bio, BIO_SEG_VALID))

		blk_recount_segments(q, bio);

	if (!bio_flagged(nxt, BIO_SEG_VALID))

		blk_recount_segments(q, nxt);

	if (bio_has_data(bio) &&

	    (!BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)) ||

	     BIOVEC_VIRT_OVERSIZE(bio->bi_hw_back_size + nxt->bi_hw_front_size)))

		return 0;

	if (bio->bi_hw_back_size + nxt->bi_hw_front_size > q->max_segment_size)

		return 0;



	return 1;

}



/*

 * map a request to scatterlist, return number of sg entries setup. Caller

 * must make sure sg can hold rq->nr_phys_segments entries
@@ -304,7 +279,6 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req, 
		     struct bio *bio)

{

	unsigned short max_sectors;

	int len;



	if (unlikely(blk_pc_request(req)))

		max_sectors = q->max_hw_sectors;
@@ -321,20 +295,6 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req, 
		blk_recount_segments(q, req->biotail);

	if (!bio_flagged(bio, BIO_SEG_VALID))

		blk_recount_segments(q, bio);

	len = req->biotail->bi_hw_back_size + bio->bi_hw_front_size;

	if (!bio_has_data(bio) || 

	    (BIOVEC_VIRT_MERGEABLE(__BVEC_END(req->biotail), __BVEC_START(bio))

	     && !BIOVEC_VIRT_OVERSIZE(len))) {

		int mergeable =  ll_new_mergeable(q, req, bio);



		if (mergeable) {

			if (req->nr_hw_segments == 1)

				req->bio->bi_hw_front_size = len;

			if (bio->bi_hw_segments == 1)

				bio->bi_hw_back_size = len;

		}

		return mergeable;

	}



	return ll_new_hw_segment(q, req, bio);

}
@@ -343,7 +303,6 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req, 
		      struct bio *bio)

{

	unsigned short max_sectors;

	int len;



	if (unlikely(blk_pc_request(req)))

		max_sectors = q->max_hw_sectors;
@@ -357,24 +316,10 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req, 
			q->last_merge = NULL;

		return 0;

	}

	len = bio->bi_hw_back_size + req->bio->bi_hw_front_size;

	if (!bio_flagged(bio, BIO_SEG_VALID))

		blk_recount_segments(q, bio);

	if (!bio_flagged(req->bio, BIO_SEG_VALID))

		blk_recount_segments(q, req->bio);

	if (!bio_has_data(bio) || 

	    (BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(req->bio)) &&

	     !BIOVEC_VIRT_OVERSIZE(len))) {

		int mergeable =  ll_new_mergeable(q, req, bio);



		if (mergeable) {

			if (bio->bi_hw_segments == 1)

				bio->bi_hw_front_size = len;

			if (req->nr_hw_segments == 1)

				req->biotail->bi_hw_back_size = len;

		}

		return mergeable;

	}



	return ll_new_hw_segment(q, req, bio);

}
@@ -406,18 +351,6 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, 
		return 0;



	total_hw_segments = req->nr_hw_segments + next->nr_hw_segments;

	if (blk_hw_contig_segment(q, req->biotail, next->bio)) {

		int len = req->biotail->bi_hw_back_size +

				next->bio->bi_hw_front_size;

		/*

		 * propagate the combined length to the end of the requests

		 */

		if (req->nr_hw_segments == 1)

			req->bio->bi_hw_front_size = len;

		if (next->nr_hw_segments == 1)

			next->biotail->bi_hw_back_size = len;

		total_hw_segments--;

	}



	if (total_hw_segments > q->max_hw_segments)

		return 0;

fs/bio.c

+2 −4
Original line number Diff line number Diff line
@@ -350,8 +350,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page 
	 */



	while (bio->bi_phys_segments >= q->max_phys_segments

	       || bio->bi_hw_segments >= q->max_hw_segments

	       || BIOVEC_VIRT_OVERSIZE(bio->bi_size)) {

	       || bio->bi_hw_segments >= q->max_hw_segments) {



		if (retried_segments)

			return 0;
@@ -395,8 +394,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page 
	}



	/* If we may be able to merge these biovecs, force a recount */

	if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec) ||

	    BIOVEC_VIRT_MERGEABLE(bvec-1, bvec)))

	if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))

		bio->bi_flags &= ~(1 << BIO_SEG_VALID);



	bio->bi_vcnt++;

include/linux/bio.h

+0 −15
Original line number Diff line number Diff line
@@ -26,21 +26,8 @@ 


#ifdef CONFIG_BLOCK



/* Platforms may set this to teach the BIO layer about IOMMU hardware. */

#include <asm/io.h>



#if defined(BIO_VMERGE_MAX_SIZE) && defined(BIO_VMERGE_BOUNDARY)

#define BIOVEC_VIRT_START_SIZE(x) (bvec_to_phys(x) & (BIO_VMERGE_BOUNDARY - 1))

#define BIOVEC_VIRT_OVERSIZE(x)	((x) > BIO_VMERGE_MAX_SIZE)

#else

#define BIOVEC_VIRT_START_SIZE(x)	0

#define BIOVEC_VIRT_OVERSIZE(x)		0

#endif



#ifndef BIO_VMERGE_BOUNDARY

#define BIO_VMERGE_BOUNDARY	0

#endif



#define BIO_DEBUG



#ifdef BIO_DEBUG
@@ -240,8 +227,6 @@ static inline void *bio_data(struct bio *bio) 
	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))

#endif



#define BIOVEC_VIRT_MERGEABLE(vec1, vec2)	\

	((((bvec_to_phys((vec1)) + (vec1)->bv_len) | bvec_to_phys((vec2))) & (BIO_VMERGE_BOUNDARY - 1)) == 0)

#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \

	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))

#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \