Re: [PATCH] char/mem: only use {read,write}_iter, not the old {read,write} functions

From: Al Viro
Date: Fri May 20 2022 - 11:44:20 EST


On Fri, May 20, 2022 at 09:32:34AM -0600, Jens Axboe wrote:

> Didn't look closer, but I'm assuming this is _mostly_ tied to needing to
> init 48 bytes of kiocb for each one. There might be ways to embed a
> sync_kiocb inside the kiocb for the bits we need there, at least that
> could get us down to 32 bytes.

My bet would be on iocb_flags() (and kiocb_set_rw_flags()) tests and
pointer-chasing, actually. I'd been sick on and off since early November,
trying to dig myself from under the piles right now. Christoph's
patches in that area are somewhere in the pile ;-/