Re: [RFC PATCH 07/11] [CLEANUP] trace-cmd: Split out binding a port and fork reader from open_udp()

[Steven Rostedt <rostedt@goodmis.org>]

On Mon, 26 Aug 2013 10:48:15 +0900
Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> wrote:


> >> +static int open_udp(const char *node, const char *port, int *pid,
> >> +		    int cpu, int pagesize, int start_port)
> >> +{
> >> +	int sfd;
> >> +	int num_port;
> >> +
> >> +	num_port = udp_bind_a_port(start_port, &sfd);
> >> +	if (num_port < 0)
> >> +		return num_port;
> >
> > I don't see how num_port could be less than zero.
> 
> I think so, but trace-cmd checks whether udp_port is less than zero or
> not in create_all_readers().
> 
> May I submit the removal patch?

It's not a critical path, the check is fine. As there was a check, I
was thinking that you were expecting it to pass an error which it never
did.

Perhaps just add a comment stating that udp_bind_a_port() currently
does not return an error, but if that changes in the future, we have a
check for it now.

That way a reviewer of the code does not get confused by it.

-- Steve