linux-kernel - Re: [PATCH 00/29] RFC: iov_iter: Switch to using an ops table

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Message-ID: <CAHk-=wj3p3eScaULtpCtWwS9NGFxT7dVTTC3mg1VyAyO2L5j7w@mail.gmail.com>
Date:   Sat, 21 Nov 2020 10:23:13 -0800
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     David Howells <dhowells@...hat.com>
Cc:     Pavel Begunkov <asml.silence@...il.com>,
        Matthew Wilcox <willy@...radead.org>,
        Jens Axboe <axboe@...nel.dk>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        linux-block <linux-block@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 00/29] RFC: iov_iter: Switch to using an ops table

On Sat, Nov 21, 2020 at 6:13 AM David Howells <dhowells@...hat.com> wrote:
>
> Can someone recommend a good way to benchmark this properly?  The problem
> is that the difference this makes relative to the amount of time taken to
> actually do I/O is tiny.

Maybe try /dev/zero -> /dev/null to try a load where the IO itself is
cheap. Or vmsplice to /dev/null?

         Linus