| Message ID | 20190309013737.27741-3-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: enable multi-page bvec for passthrough IO | expand |
On Sat, Mar 09, 2019 at 09:37:33AM +0800, Ming Lei wrote: > For normal filesystem IO, each page is added via blk_add_page(), > in which bvec(page) merge has been handled already, and basically > not possible to merge two adjacent bvecs in one bio. > > So not try to merge two adjacent bvecs in blk_queue_split(), also add > check if one page is mergeable to current bvec in bio_add_page() for > avoiding to break XEN. Isn't this two entirely different things? Both look good to me, but I don't understand why this is one patch vs two.
On Sat, Mar 09, 2019 at 09:37:33AM +0800, Ming Lei wrote: > For normal filesystem IO, each page is added via blk_add_page(), > in which bvec(page) merge has been handled already, and basically > not possible to merge two adjacent bvecs in one bio. > > So not try to merge two adjacent bvecs in blk_queue_split(), also add > check if one page is mergeable to current bvec in bio_add_page() for > avoiding to break XEN. > > Cc: ris Ostrovsky <boris.ostrovsky@oracle.com> > Cc: Juergen Gross <jgross@suse.com> > Cc: xen-devel@lists.xenproject.org > Cc: Omar Sandoval <osandov@fb.com> > Cc: Christoph Hellwig <hch@lst.de> > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/bio.c | 2 ++ > block/blk-merge.c | 17 ----------------- > 2 files changed, 2 insertions(+), 17 deletions(-) > > diff --git a/block/bio.c b/block/bio.c > index 71a78d9fb8b7..d8f48188937c 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -776,6 +776,8 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page, > > if (vec_end_addr + 1 != page_addr + off) > return false; > + if (xen_domain() && !xen_biovec_phys_mergeable(bv, page)) > + return false; > if (same_page && (vec_end_addr & PAGE_MASK) != page_addr) > return false; > Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
On Mon, Mar 11, 2019 at 03:21:06PM +0100, Christoph Hellwig wrote: > On Sat, Mar 09, 2019 at 09:37:33AM +0800, Ming Lei wrote: > > For normal filesystem IO, each page is added via blk_add_page(), > > in which bvec(page) merge has been handled already, and basically > > not possible to merge two adjacent bvecs in one bio. > > > > So not try to merge two adjacent bvecs in blk_queue_split(), also add > > check if one page is mergeable to current bvec in bio_add_page() for > > avoiding to break XEN. > > Isn't this two entirely different things? Both look good to me, > but I don't understand why this is one patch vs two. You are right, it should have been two things logically. Thanks, Ming
diff --git a/block/bio.c b/block/bio.c index 71a78d9fb8b7..d8f48188937c 100644 --- a/block/bio.c +++ b/block/bio.c @@ -776,6 +776,8 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page, if (vec_end_addr + 1 != page_addr + off) return false; + if (xen_domain() && !xen_biovec_phys_mergeable(bv, page)) + return false; if (same_page && (vec_end_addr & PAGE_MASK) != page_addr) return false; diff --git a/block/blk-merge.c b/block/blk-merge.c index 1c9d4f0f96ea..aa9164eb7187 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -267,23 +267,6 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, goto split; } - if (bvprvp) { - if (seg_size + bv.bv_len > queue_max_segment_size(q)) - goto new_segment; - if (!biovec_phys_mergeable(q, bvprvp, &bv)) - goto new_segment; - - seg_size += bv.bv_len; - bvprv = bv; - bvprvp = &bvprv; - sectors += bv.bv_len >> 9; - - if (nsegs == 1 && seg_size > front_seg_size) - front_seg_size = seg_size; - - continue; - } -new_segment: if (nsegs == max_segs) goto split;
For normal filesystem IO, each page is added via blk_add_page(), in which bvec(page) merge has been handled already, and basically not possible to merge two adjacent bvecs in one bio. So not try to merge two adjacent bvecs in blk_queue_split(), also add check if one page is mergeable to current bvec in bio_add_page() for avoiding to break XEN. Cc: ris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: xen-devel@lists.xenproject.org Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- block/bio.c | 2 ++ block/blk-merge.c | 17 ----------------- 2 files changed, 2 insertions(+), 17 deletions(-)