Subject: Re: have scsibus sleep only one time
To: Bill Studenmund <email@example.com>
From: Manuel Bouyer <firstname.lastname@example.org>
Date: 03/10/2003 18:16:35
On Mon, Mar 10, 2003 at 09:10:49AM -0800, Bill Studenmund wrote:
> On Sun, 9 Mar 2003, Matt Thomas wrote:
> > At 06:04 PM 3/9/2003, matthew green wrote:
> > >
> > > Hi,
> > > would anyone object to the attached change ?
> > > It makes all the attached scsibusses sleep "in parallel" instead of
> > > sequencially, which is a real win for machines with several SCSI busses.
> > > On my DS20, which has 8 scsi busses, this saves 14 seconds on boot.
> > >
> > >
> > >i think this change is a wonderful idea.
> > There is one issue with this. If you don't wire down your scsi devices
> > in your config file, they may get attached in random order.
> I thought that's what the mutex in there was for?
> Oh, I see. All the busses could go to sleep, then wake randomly. Then we
> will be polling busses in wake-order, not probe-order.
No, it should not. The scsi_initq queue is there to prevent that.
See the for(;;) loop in scsibus_config()
Manuel Bouyer, LIP6, Universite Paris VI. Manuel.Bouyer@lip6.fr
NetBSD: 24 ans d'experience feront toujours la difference