On 2/27/19 5:40 AM, Ming Lei wrote:

Hi,

The 1st patch introduce bvec_nth_page(), so that nth_page() can
be avoided if the bvec is single-page.

The 2nd and 3rd patch adds fast path for single-page bvec case.

The last patch introduces a light-weight helper for iterating over
pages, which may improve __bio_iov_bvec_add_pages(). This patch
is for io_uring.

This reclaims another 2%, we're now at 1585K for the test case.
Definite improvement!

-- 
Jens Axboe