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authorMikulas Patocka <mpatocka@redhat.com>2008-08-15 10:15:19 +0200
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 08:56:03 +0200
commitb8b3e16cfe6435d961f6aaebcfd52a1ff2a988c5 (patch)
tree5832535c112c0504590256cb8a0bcabc6e282be3 /block/blk-merge.c
parent6a421c1dc94b12923294a359822346f12492de5e (diff)
downloadlwn-b8b3e16cfe6435d961f6aaebcfd52a1ff2a988c5.tar.gz
lwn-b8b3e16cfe6435d961f6aaebcfd52a1ff2a988c5.zip
block: drop virtual merging accounting
Remove virtual merge accounting. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/blk-merge.c')
-rw-r--r--block/blk-merge.c79
1 files changed, 6 insertions, 73 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 6cf8f0c70a51..2c2a2ee716ec 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;