From: NeilBrown <neilb@suse.de>
To: linux-kernel@vger.kernel.org
Subject: [PATCH 016 of 35] Centralise setting for REQ_NOMERGE.
Date: Tue, 31 Jul 2007 12:17:11 +1000 [thread overview]
Message-ID: <1070731021711.25318@suse.de> (raw)
In-Reply-To: 20070731112539.22428.patches@notabene
Every error return from ll_{front,back}_merge_fn sets
REQ_NOMERGE. So move this to after the call to these functions.
This is only a small saving here, but will help a future patch.
Signed-off-by: Neil Brown <neilb@suse.de>
### Diffstat output
./block/ll_rw_blk.c | 43 +++++++++++++++++++------------------------
1 file changed, 19 insertions(+), 24 deletions(-)
diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c
--- .prev/block/ll_rw_blk.c 2007-07-31 11:21:00.000000000 +1000
+++ ./block/ll_rw_blk.c 2007-07-31 11:21:01.000000000 +1000
@@ -1373,12 +1373,8 @@ static inline int ll_new_mergeable(struc
{
if (req->nr_phys_segments + nreq->nr_phys_segments
- > q->max_phys_segments) {
- req->cmd_flags |= REQ_NOMERGE;
- if (req == q->last_merge)
- q->last_merge = NULL;
+ > q->max_phys_segments)
return 0;
- }
/*
* A hw segment is just getting larger, bump just the phys
@@ -1395,12 +1391,8 @@ static inline int ll_new_hw_segment(stru
if (req->nr_hw_segments + nreq->nr_hw_segments > q->max_hw_segments
|| (req->nr_phys_segments + nreq->nr_phys_segments
- > q->max_phys_segments)) {
- req->cmd_flags |= REQ_NOMERGE;
- if (req == q->last_merge)
- q->last_merge = NULL;
+ > q->max_phys_segments))
return 0;
- }
/*
* This will form the start of a new hw segment. Bump both
@@ -1422,12 +1414,9 @@ static int ll_back_merge_fn(struct reque
else
max_sectors = q->max_sectors;
- if (req->nr_sectors + nreq->nr_sectors > max_sectors) {
- req->cmd_flags |= REQ_NOMERGE;
- if (req == q->last_merge)
- q->last_merge = NULL;
+ if (req->nr_sectors + nreq->nr_sectors > max_sectors)
return 0;
- }
+
len = req->hw_back_size + nreq->hw_front_size;
if (nreq->first_offset == 0 &&
BIOVEC_VIRT_MERGEABLE(__BVEC_END(req->biotail),
@@ -1459,12 +1448,9 @@ static int ll_front_merge_fn(struct requ
max_sectors = q->max_sectors;
- if (req->nr_sectors + nreq->nr_sectors > max_sectors) {
- req->cmd_flags |= REQ_NOMERGE;
- if (req == q->last_merge)
- q->last_merge = NULL;
+ if (req->nr_sectors + nreq->nr_sectors > max_sectors)
return 0;
- }
+
len = nreq->hw_back_size + req->hw_front_size;
if (BIOVEC_VIRT_MERGEABLE(__BVEC_END(nreq->biotail),
@@ -2347,9 +2333,10 @@ int blk_rq_append_bio(struct request_que
if (!rq->bio)
blk_rq_bio_prep(q, rq, bio);
- else if (!ll_back_merge_fn(q, rq, &nreq))
+ else if (!ll_back_merge_fn(q, rq, &nreq)) {
+ rq->cmd_flags |= REQ_NOMERGE;
return -EINVAL;
- else {
+ } else {
rq->biotail->bi_next = bio;
rq->biotail = bio;
rq->hw_back_size = nreq.hw_back_size;
@@ -2959,8 +2946,12 @@ static int __make_request(struct request
case ELEVATOR_BACK_MERGE:
BUG_ON(!rq_mergeable(req));
- if (!ll_back_merge_fn(q, req, &nreq))
+ if (!ll_back_merge_fn(q, req, &nreq)) {
+ req->cmd_flags |= REQ_NOMERGE;
+ if (req == q->last_merge)
+ q->last_merge = NULL;
break;
+ }
blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
@@ -2977,8 +2968,12 @@ static int __make_request(struct request
case ELEVATOR_FRONT_MERGE:
BUG_ON(!rq_mergeable(req));
- if (!ll_front_merge_fn(q, req, &nreq))
+ if (!ll_front_merge_fn(q, req, &nreq)) {
+ req->cmd_flags |= REQ_NOMERGE;
+ if (req == q->last_merge)
+ q->last_merge = NULL;
break;
+ }
blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
next prev parent reply other threads:[~2007-07-31 2:23 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-31 2:15 [PATCH 000 of 35] Refactor block layer to improve support for stacked devices NeilBrown
2007-07-31 2:15 ` [PATCH 001 of 35] Replace bio_data with blk_rq_data NeilBrown
2007-07-31 2:15 ` [PATCH 002 of 35] Replace bio_cur_sectors with blk_rq_cur_sectors NeilBrown
2007-07-31 2:16 ` [PATCH 003 of 35] Introduce rq_for_each_segment replacing rq_for_each_bio NeilBrown
2007-07-31 2:16 ` [PATCH 004 of 35] Merge blk_recount_segments into blk_recalc_rq_segments NeilBrown
2007-07-31 2:16 ` [PATCH 005 of 35] Stop updating bi_idx, bv_len, bv_offset when a request completes NeilBrown
2007-08-01 14:54 ` Tejun Heo
2007-07-31 2:16 ` [PATCH 006 of 35] Only call bi_end_io once for any bio NeilBrown
2007-07-31 2:16 ` [PATCH 007 of 35] Drop 'size' argument from bio_endio and bi_end_io NeilBrown
2007-08-01 15:17 ` Tejun Heo
2007-07-31 2:16 ` [PATCH 008 of 35] Introduce bi_iocnt to count requests sharing the one bio NeilBrown
2007-08-01 15:49 ` Tejun Heo
2007-07-31 2:16 ` [PATCH 009 of 35] Remove overloading of bi_hw_segments in raid5 NeilBrown
2007-07-31 2:16 ` [PATCH 010 of 35] New function blk_req_append_bio NeilBrown
2007-08-01 15:54 ` Christoph Hellwig
2007-07-31 2:16 ` [PATCH 011 of 35] Stop exporting blk_rq_bio_prep NeilBrown
2007-07-31 2:16 ` [PATCH 012 of 35] Share code between init_request_from_bio and blk_rq_bio_prep NeilBrown
2007-07-31 2:16 ` [PATCH 013 of 35] Don't update bi_hw_*_size if we aren't going to merge NeilBrown
2007-08-01 15:57 ` Tejun Heo
2007-08-02 3:37 ` Neil Brown
2007-07-31 2:17 ` [PATCH 014 of 35] Change blk_phys/hw_contig_segment to take requests, not bios NeilBrown
2007-07-31 2:17 ` [PATCH 015 of 35] Move hw_front_size and hw_back_size from bio to request NeilBrown
2007-07-31 2:17 ` NeilBrown [this message]
2007-07-31 2:17 ` [PATCH 017 of 35] Fix various abuse of bio fields in umem.c NeilBrown
2007-07-31 2:17 ` [PATCH 018 of 35] Remove bi_idx NeilBrown
2007-07-31 2:17 ` [PATCH 019 of 35] Convert bio_for_each_segment to fill in a fresh bio_vec NeilBrown
2007-08-01 16:21 ` Tejun Heo
2007-07-31 2:17 ` [PATCH 020 of 35] Add bi_offset and allow a bio to reference only part of a bi_io_vec NeilBrown
2007-07-31 2:17 ` [PATCH 021 of 35] Teach umem.c about bi_offset and to limit to bi_size NeilBrown
2007-07-31 2:17 ` [PATCH 022 of 35] Teach dm-crypt to honour bi_offset and bi_size NeilBrown
2007-07-31 2:17 ` [PATCH 023 of 35] Teach pktcdvd.c " NeilBrown
2007-07-31 2:17 ` [PATCH 024 of 35] Allow request bio list not to end with NULL NeilBrown
2007-07-31 2:17 ` [PATCH 025 of 35] Treat rq->hard_nr_sectors as setting an overriding limit in the size of the request NeilBrown
2007-08-01 17:44 ` Tejun Heo
2007-08-02 3:31 ` Neil Brown
2007-08-02 5:03 ` Tejun Heo
2007-07-31 2:18 ` [PATCH 026 of 35] Split any large bios that arrive at __make_request NeilBrown
2007-08-01 17:56 ` Tejun Heo
2007-08-02 0:49 ` Neil Brown
2007-08-02 2:59 ` Tejun Heo
2007-08-02 3:16 ` Neil Brown
2007-07-31 2:18 ` [PATCH 028 of 35] Split arbitrarily large requests to md/raid0 and md/linear NeilBrown
2007-07-31 2:18 ` [PATCH 029 of 35] Teach md/raid10 to split arbitrarily large bios NeilBrown
2007-07-31 2:18 ` [PATCH 030 of 35] Teach raid5 to split incoming bios NeilBrown
2007-07-31 2:18 ` [PATCH 031 of 35] Use bio_multi_split to fully split bios for pktcdvd NeilBrown
2007-07-31 2:18 ` [PATCH 032 of 35] Remove blk_queue_merge_bvec and bio_split and related code NeilBrown
2007-07-31 2:18 ` [PATCH 033 of 35] Simplify stacking of IO restrictions NeilBrown
2007-07-31 2:18 ` [PATCH 034 of 35] Simplify bio_add_page and raid1/raid10 resync which use it NeilBrown
2007-07-31 2:18 ` [PATCH 035 of 35] Simplify bio splitting in dm NeilBrown
2007-07-31 15:28 ` [PATCH 000 of 35] Refactor block layer to improve support for stacked devices Avi Kivity
2007-08-01 14:37 ` Tejun Heo
2007-08-01 15:52 ` John Stoffel
2007-08-01 15:59 ` Tejun Heo
2007-08-02 3:43 ` Neil Brown
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