Subject: Re: SIGINFO and NOKERNINFO
To: None <tech-kern@netbsd.org>
From: Christos Zoulas <christos@astron.com>
List: tech-kern
Date: 06/05/2006 01:17:16
In article <200606042309.TAA11114@Sparkle.Rodents.Montreal.QC.CA>,
der Mouse  <mouse@Rodents.Montreal.QC.CA> wrote:
>> In the end, the more basic issue is that there should be a way to
>> avoid printing kerninfo in the current process, that does not modify
>> global state [the tty state] that persists after the process ends.
>
>> Chuck had a good idea, indicating this via a signal flag.  The
>> following code does this.
>
>> Opinions?
>
>I think the problem description is accurate.  I see some potential
>problems, though.
>
>In particular, what if the foreground process group contains multiple
>processes, some of which set this bit and some of which don't?  Reading
>the patch, it appears to pick some favoured process (according to
>proc_compare()) and let that process's setting control.  This is
>probably a reasonable first cut, but I'm not at all convinced it's the
>rightest answer available.

This is what the code used to do before. We have to pick the "foreground"
process since we print information only for one process.

>Also, it seems that this then wants the tty setting to be a three-way
>switch: (1) never print kernel info, (2) always print kernel info, (3)
>let process signal flags control (with whatever resolution of the above
>issue is decided upon).

Well, I thought about that and decided that this would make things
even more complicated. Now things work exactly like before insofar
NOKERNINFO goes. 

dhristos