Subject: Re: changing default for UFS_DIRHASH and NEW_BUFQ_STRATEGY
To: None <tech-kern@netbsd.org>
From: Juergen Hannken-Illjes <hannken@eis.cs.tu-bs.de>
List: tech-kern
Date: 06/03/2005 18:11:22
On Fri, Jun 03, 2005 at 11:42:12AM -0400, Perry E. Metzger wrote:
> 
> Frank van der Linden <fvdl@netbsd.org> writes:
> > On Fri, Jun 03, 2005 at 10:57:36AM -0400, Perry E. Metzger wrote:
> >> UFS_DIRHASH and NEW_BUFQ_STRATEGY are reputedly stable for all the
> >> people using them, but we still have them commented out in our
> >> GENERICs.
> >> 
> >> I'd like to propose uncommenting them out, i.e. turning them on by
> >> default.
> >
> > As I recal, Juergen has said that NEW_BUFQ_STRATEGY works fine in a few
> > circumstances, but not in others, and that he didn't favor enabling it by
> > default. I'll have to go with the author's opinion on that one.
> 
> I didn't think Juergen was the author of NEW_BUFQ_STRATEGY, and I
> don't remember anyone complaining about it in any way at all for
> literally years now. Are you sure about this?

I was the author :-) NEW_BUFQ_STRATEGY works fine in the single-disk-
interactive-desktop case. But it will make things worse in most real
server situations where we have many disks / tagged command queuing.

After all it was just an example for the new bufq API.

Please leave it commented out.
-- 
Juergen Hannken-Illjes - hannken@eis.cs.tu-bs.de - TU Braunschweig (Germany)