Messages in this thread | | | Subject | Re: [PATCH V7 20/24] bcache: avoid to use bio_for_each_segment_all() in bch_bio_alloc_pages() | From | Coly Li <> | Date | Wed, 27 Jun 2018 23:55:33 +0800 |
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On 2018/6/27 8:45 PM, Ming Lei wrote: > bch_bio_alloc_pages() is always called on one new bio, so it is safe > to access the bvec table directly. Given it is the only kind of this > case, open code the bvec table access since bio_for_each_segment_all() > will be changed to support for iterating over multipage bvec. > > Cc: Coly Li <colyli@suse.de> > Cc: linux-bcache@vger.kernel.org > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > drivers/md/bcache/util.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c > index fc479b026d6d..9f2a6fd5dfc9 100644 > --- a/drivers/md/bcache/util.c > +++ b/drivers/md/bcache/util.c > @@ -268,7 +268,7 @@ int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) > int i; > struct bio_vec *bv; >
Hi Ming,
> - bio_for_each_segment_all(bv, bio, i) { > + for (i = 0, bv = bio->bi_io_vec; i < bio->bi_vcnt; bv++) {
Is it possible to treat this as a special condition of bio_for_each_segement_all() ? I mean only iterate one time in bvec_for_each_segment(). I hope the above change is not our last choice before I reply an Acked-by :-)
Thanks.
Coly Li
> bv->bv_page = alloc_page(gfp_mask); > if (!bv->bv_page) { > while (--bv >= bio->bi_io_vec) >
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