Re: [PATCH net-next v5 03/16] ceph: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage

[Ilya Dryomov]

On Mon, Jun 26, 2023 at 5:12 PM David Howells <dhowells@xxxxxxxxxx> wrote:
>
> Ilya Dryomov <idryomov@xxxxxxxxx> wrote:
>
> > > -       int flags = MSG_DONTWAIT | MSG_NOSIGNAL | more;
>
> Btw, why are you setting MSG_DONTWAIT?  If you're in the middle of
> transmitting a message on a TCP socket, surely you can't just switch to
> transmitting a different message on the same socket without doing some sort of
> reframing?

We don't want to hog kworker threads.  You are correct that we can't
switch to transmitting a different message on the same socket but Ceph
is massively parallel and there can be dozens or even hundreds of other
sockets to work on.

Thanks,

                Ilya