On Tue, Feb 16, 2016 at 4:27 AM, Sagi Grimberg <sa...@dev.mellanox.co.il> wrote: > >>>> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h >>>> index 4571ef1..b8ff6a3 100644 >>>> --- a/include/linux/blkdev.h >>>> +++ b/include/linux/blkdev.h >>>> @@ -1388,7 +1388,7 @@ static inline bool bvec_gap_to_prev(struct >>>> request_queue *q, >>>> static inline bool bio_will_gap(struct request_queue *q, struct bio >>>> *prev, >>>> struct bio *next) >>>> { >>>> - if (!bio_has_data(prev)) >>>> + if (!bio_has_data(prev) || !queue_virt_boundary(q)) >>>> bio_integrity_add_page return false; >>> >>> >>> >>> Can we not do that? >> >> >> Given there are only 3 drivers which set virt boundary, I think >> it is reasonable to do that. > > > 3 drivers that are really performance critical. I don't think we > should add optimized branching for some of the drivers especially > when the drivers that do set virt_boundary *really* care about latency.
I don't think the extra check on bvec_gap_to_prev() can make any difference, but if you do care we can introduce __bvec_gap_to_prev() in which the check is moved into bio_will_gap(). Thanks,