On Fri, Sep 10, 2021 at 09:08:02AM -0600, Jens Axboe wrote: > > You actually can cut it down even more - nr_segs + iov remains constant > > all along, so you could get away with just 3 words here... I would be > > Mmm, the iov pointer remains constant? Maybe I'm missing your point, but > the various advance functions are quite happy to increment iter->iov or > iter->bvec, so we need to restore them. From a quick look, looks like > iter->nr_segs is modified for advancing too. > > What am I missing? i->iov + i->nr_segs does not change - the places incrementing the former will decrement the latter by the same amount. So it's enough to store either of those - the other one can be recovered by subtracting the saved value from the current i->iov + i->nr_segs.
