diff options
| -rw-r--r-- | block/blk-merge.c | 20 | ||||
| -rw-r--r-- | include/linux/bio.h | 7 |
2 files changed, 25 insertions, 2 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index 908d3e11ac5..8681cd6f991 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -77,12 +77,20 @@ void blk_recalc_rq_segments(struct request *rq) continue; } new_segment: + if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size) + rq->bio->bi_seg_front_size = seg_size; + nr_phys_segs++; bvprv = bv; seg_size = bv->bv_len; highprv = high; } + if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size) + rq->bio->bi_seg_front_size = seg_size; + if (seg_size > rq->biotail->bi_seg_back_size) + rq->biotail->bi_seg_back_size = seg_size; + rq->nr_phys_segments = nr_phys_segs; } @@ -106,7 +114,8 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio, if (!test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags)) return 0; - if (bio->bi_size + nxt->bi_size > q->max_segment_size) + if (bio->bi_seg_back_size + nxt->bi_seg_front_size > + q->max_segment_size) return 0; if (!bio_has_data(bio)) @@ -309,6 +318,8 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, struct request *next) { int total_phys_segments; + unsigned int seg_size = + req->biotail->bi_seg_back_size + next->bio->bi_seg_front_size; /* * First check if the either of the requests are re-queued @@ -324,8 +335,13 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, return 0; total_phys_segments = req->nr_phys_segments + next->nr_phys_segments; - if (blk_phys_contig_segment(q, req->biotail, next->bio)) + if (blk_phys_contig_segment(q, req->biotail, next->bio)) { + if (req->nr_phys_segments == 1) + req->bio->bi_seg_front_size = seg_size; + if (next->nr_phys_segments == 1) + next->biotail->bi_seg_back_size = seg_size; total_phys_segments--; + } if (total_phys_segments > q->max_phys_segments) return 0; diff --git a/include/linux/bio.h b/include/linux/bio.h index ff5b4cf9e2d..dc3cec386a9 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -79,6 +79,13 @@ struct bio { unsigned int bi_size; /* residual I/O count */ + /* + * To keep track of the max segment size, we account for the + * sizes of the first and last mergeable segments in this bio. + */ + unsigned int bi_seg_front_size; + unsigned int bi_seg_back_size; + unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ unsigned int bi_comp_cpu; /* completion CPU */ |