Hi,
Now the whole IO stack is capable of handling multi-page bvec, and it has
been enabled in the normal FS IO path. However, it isn't done for
passthrough IO.
Without enabling multi-bvec for passthough IO, we won't go ahead for
optimizing related IO paths, such as bvec merging, bio_add_pc_page
simplification.
This patch enables multi-page bvec for passthrough IO. Turns out
bio_add_pc_page() is simpliefied a lot, especially the physical segment
number of passthrough bio is always same with bio.bi_vcnt. Also the
bvec merging inside bio is killed.
blktests(block/029) is added for covering passthough IO path, and this
patchset does pass the new block/029 test.
V3:
- fix build warning on patch 1 and 7, only the two patches are
changed
V2:
- add new patch of 'block: avoid to break XEN by multi-page bvec'
- add one new patch to cleanup bio_add_pc_page()
- add another two new patches for cleanup of mapping bvec to sg
- most of others are patch style changes
Ming Lei (10):
block: pass page to xen_biovec_phys_mergeable
block: avoid to break XEN by multi-page bvec
block: don't merge adjacent bvecs to one segment in bio
blk_queue_split
block: cleanup bio_add_pc_page
block: check if page is mergeable in one helper
block: put the same page when adding it to bio
block: enable multi-page bvec for passthrough IO
block: remove argument of 'request_queue' from __blk_bvec_map_sg
block: reuse __blk_bvec_map_sg() for mapping page sized bvec
block: don't check if adjacent bvecs in one bio can be mergeable
block/bio.c | 134 ++++++++++++++++++++++++++++---------------------
block/blk-merge.c | 106 +++++++++++++++++++-------------------
block/blk.h | 2 +-
drivers/xen/biomerge.c | 5 +-
include/linux/bio.h | 3 ++
include/xen/xen.h | 4 +-
6 files changed, 137 insertions(+), 117 deletions(-)
--
2.9.5
