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Date:   Fri, 14 May 2021 09:12:05 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc:     Linux Trace Devel <linux-trace-devel@vger.kernel.org>
Subject: Re: [PATCH v3 2/2] trace-cmd: Trace timesync to find pids that map
 vCPUs
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On Fri, 14 May 2021 07:10:51 +0300
Tzvetomir Stoyanov <tz.stoyanov@gmail.com> wrote:

> > @@ -3250,10 +3282,18 @@ static char *parse_guest_name(char *gname, int *cid, int *port)
> >         } else if (is_digits(gname))
> >                 *cid = atoi(gname);
> >
> > -       read_qemu_guests();
> > +       if (*cid < 0)
> > +               read_qemu_guests();
> > +
> > +       if (*cid < 0)
> > +               return NULL;  
> 
> This check is not needed. If cid is not part of the string, let
> read_qemu_guests() to try discover the VMs, instead of returning NULL.

I'm confused. That's basically what the above does.

	*cid = -1;

	if (<cid is in name>) {
		*cid = look_for_cid_via_tracing();
	}

	if (*cid < -1)
		read_qemu_guests();

That is, if the cid isn't part of the name, then it will call
read_qemu_guests().

The second check is in case the read_qemu_guests() fails to find the cid
either.

What am I missing?

-- Steve