From b8b3e16cfe6435d961f6aaebcfd52a1ff2a988c5 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Fri, 15 Aug 2008 10:15:19 +0200 Subject: [PATCH] block: drop virtual merging accounting Remove virtual merge accounting. Signed-off-by: Mikulas Patocka Signed-off-by: Jens Axboe --- block/blk-merge.c | 79 ++++----------------------------------------- fs/bio.c | 6 ++-- include/linux/bio.h | 15 --------- 3 files changed, 8 insertions(+), 92 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 6cf8f0c70a5..2c2a2ee716e 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -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; - nr_hw_segs++; - } + 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 = 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; diff --git a/fs/bio.c b/fs/bio.c index 3cba7ae34d7..4ac7c59d1c6 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -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++; diff --git a/include/linux/bio.h b/include/linux/bio.h index 33c3947d61e..894d16ce002 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -26,21 +26,8 @@ #ifdef CONFIG_BLOCK -/* Platforms may set this to teach the BIO layer about IOMMU hardware. */ #include -#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) \ -- 2.20.1