Commit 09fa190d authored by Andrey Filippov's avatar Andrey Filippov
Browse files

making single-command write

parent 8209132f

src/block/bio.c

+17 −1
Original line number Original line Diff line number Diff line
@@ -852,7 +852,23 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
	size_t offset;

	size_t offset;

	ssize_t size;

	ssize_t size;

	if (bio->bi_disk && (bio->bi_disk->major == 8)) { // sda, sda*

	if (bio->bi_disk && (bio->bi_disk->major == 8)) { // sda, sda*

		pr_debug(" *A* nr_pages=0x%04x,bio->bi_max_vecs=0x%04x, bio->bi_vcnt==0x%04x", nr_pages, bio->bi_max_vecs, bio->bi_vcnt); //  *A* nr_pages=0x009f,bio->bi_max_vecs=0x009f, bio->bi_vcnt==0x0000

		pr_debug(" *A* nr_pages=0x%04x,bio->bi_max_vecs=0x%04x, bio->bi_vcnt=0x%04x", nr_pages, bio->bi_max_vecs, bio->bi_vcnt); //  *A* nr_pages=0x009f,bio->bi_max_vecs=0x009f, bio->bi_vcnt==0x0000

		pr_debug(" *A0* max_hw_sectors=%d,  max_dev_sectors=%d, max_sectors=%d, cluster=%d, max_segment_size=0x%08x",\

				bio->bi_disk->queue->limits.max_hw_sectors, bio->bi_disk->queue->limits.max_dev_sectors, bio->bi_disk->queue->limits.max_sectors, bio->bi_disk->queue->limits.cluster, bio->bi_disk->queue->limits.max_segment_size);

// For now - just testing, not clear who/what sets 	// bio:__bio_iov_iter_get_pages:857:  *A0* max_hw_sectors=65535,  max_dev_sectors=65535, max_sectors=2560

// limited by BLK_DEF_MAX_SECTORS = 2560!

/* blk_queue_cluster(q) return q->limits.cluster; q->limits.max_segment_size

https://patchwork.kernel.org/project/linux-block/patch/21cf85d32278bbe5acbc3def0a6db75db98a2670.1459269590.git.shli@fb.com/

bio_alloc_bioset() allocates bvecs from bvec_slabs which can only

allocate maximum 256 bvec (eg, 1M for 4k pages). We can't bump

BLK_DEF_MAX_SECTORS to exceed this value otherwise bio_alloc_bioset will

fail.

*/

		blk_queue_max_segment_size(bio->bi_disk->queue, 0x100000);

//		blk_queue_max_hw_sectors(bio->bi_disk->queue, bio->bi_disk->queue->limits.max_hw_sectors); // still used constant

		bio->bi_disk->queue->limits.max_sectors = min(bio->bi_disk->queue->limits.max_hw_sectors, bio->bi_disk->queue->limits.max_dev_sectors);

		pr_debug(" *A1* max_hw_sectors=%d,  max_dev_sectors=%d, max_sectors=%d, cluster=%d, max_segment_size=0x%08x",\

				bio->bi_disk->queue->limits.max_hw_sectors, bio->bi_disk->queue->limits.max_dev_sectors, bio->bi_disk->queue->limits.max_sectors, bio->bi_disk->queue->limits.cluster, bio->bi_disk->queue->limits.max_segment_size);

		pr_debug(" *B* niter->type=%d, iter->iov_offset=0x%08x, iter->count=0x%08x, iter->nr_segs=0x%08lx",\

		pr_debug(" *B* niter->type=%d, iter->iov_offset=0x%08x, iter->count=0x%08x, iter->nr_segs=0x%08lx",\

				iter->type, iter->iov_offset,iter->count,iter->nr_segs); // *B* niter->type=1, iter->iov_offset=0x00000000, iter->count=0x0009f000, iter->nr_segs=0x00000001

				iter->type, iter->iov_offset,iter->count,iter->nr_segs); // *B* niter->type=1, iter->iov_offset=0x00000000, iter->count=0x0009f000, iter->nr_segs=0x00000001

	}

	}

src/block/blk-merge.c

0 → 100644
+897 −0

File added.

Preview size limit exceeded, changes collapsed.

src/block/blk-mq.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -1832,7 +1832,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) 
    }

    }

	blk_queue_split(q, &bio);

	blk_queue_split(q, &bio);





    if (bio->bi_disk && (bio->bi_disk->major == 8)) { // sda, sda*

    if (bio->bi_disk && (bio->bi_disk->major == 8)) { // sda, sda* already split - 0xa segments (16 pages each)

    	pr_debug(" *2* bio->bi_flags=0x%04x, bio->bi_phys_segments=0x%08x",bio->bi_flags, bio->bi_phys_segments); // already set

    	pr_debug(" *2* bio->bi_flags=0x%04x, bio->bi_phys_segments=0x%08x",bio->bi_flags, bio->bi_phys_segments); // already set

    }

    }