Re: [PATCH/RFC] Re: recvmmsg() timeout behavior strangeness [RESEND]

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Fri, May 23, 2014 at 03:00:55PM -0400, David Miller escreveu:
> From: Arnaldo Carvalho de Melo <acme@kernel.org>
> Date: Wed, 21 May 2014 18:05:35 -0300

> > But after thinking a bit more, looks like we need to do that, please
> > take a look at the attached patch to see if it addresses the problem.

> > Mostly it adds a new timeop to the per protocol recvmsg()
> > implementations, that, if not NULL, should be used instead of
> > SO_RCVTIMEO.

> > since the underlying recvmsg implementations already check that timeout,
> > return what is remaining, that will then be used in subsequent recvmsg
> > calls, at the end we just convert it back to timespec format.

> > In most cases it is just passed to skb_recv_datagram, that will check
> > the pointer, use it and update if not NULL.

> > Should have no problems, but I only did a boot with a system with this
> > patch applied, no problems noticed on a normal desktop session, ssh,
> > etc.
 
> This looks fine to me, but I have a small request:
 
> +	return noblock ? 0 : timeop ? *timeop : sk->sk_rcvtimeo;
 
> I keep forgetting which way these expressions associate, so if you could
> parenthesize the innermost ?: I'd appreciate it. :)

Ok, I actually wrote a sample program to verify that these ternaries did
what I meant 8)

I'll finish the cset log and do this clarification change.

Would be great to get Acked-by tags from the original reporter, Michael
and whoever had a look at this change, if possible. Michael, Elie?
 
> Thanks!

Thanks a lot for reviewing it!

- Arnaldo