On Mon, Mar 27, 2023 at 05:27:13PM -0600, Jens Axboe wrote: > Add a special case to __import_iovec(), which imports a single segment > iovec as an ITER_UBUF rather than an ITER_IOVEC. ITER_UBUF is cheaper > to iterate than ITER_IOVEC, and for a single segment iovec, there's no > point in using a segmented iterator. Won't that enforce the "single-segment readv() is always identical to read()"? We'd been through that before - some of infinibarf drvivers have two different command sets, one reached via read(), another - via readv(). It's a userland ABI. Misdesigned one, but that's infinibarf for you. Does anyone really need this particular microoptimization?
