On Sun, Oct 29, 2006 at 11:25:11PM +0100, Nicolas Joly wrote:
> On Sun, Oct 29, 2006 at 08:47:49PM +0100, Manuel Bouyer wrote:
> > On Sun, Oct 29, 2006 at 10:58:24AM +0100, Nicolas Joly wrote:
> > > 
> > > Hi,
> > > 
> > > I use, at home, a pretty old i386 machine with a VT82C686A IDE
> > > controller supported by the viaide(4) driver. It worked fine until
> > > recently (SATA support changes ?), but now i'm experiencing some
> > > problems ...
> > > 
> > > The machine becomes unresponsive with not so heavy disk access; by
> > > example, while trying to create/update system building tools. At that
> > > time, after recovering, simply getting a new xterm show that the disks
> > > get 100% busy for a few second.
> > 
> > I can't see how the SATA changes could be responsible for this; the code
> > used by non-SATA controllers was not touched. Do you get any message
> > in dmesg ? Are you sure your box is not swapping ?
> 
> I currently have no real evidence that viaide changes are involved,
> but the problems started at the same time, when i upgraded my system.
> 
> Unfortunately, no message at all in dmesg ... And no, my system is not
> swapping. For now, just before and during the hangs, `sysstat -w 1 vm'
> command report a 100% disk usage, and the disk light is always on.

I was wrong for swapping. Simply building a kernel make it swap, and
then behive badly ...

Here is the scenario i made, and the memory/swap footprint seen with
top(1):

1) Boot kernel, everything fine.
Memory: 41M Act, 4068K Wired, 9556K Exec, 11M File, 290M Free
Swap: 4096M Total, 4096M Free

2) build kernel (no parallelism). After some time swapping arise ...
Memory: 9756K Act, 5256K Inact, 4004K Wired, 4280K Exec, 2220K File, 1252K Free
Swap: 4096M Total, 78M Used, 4018M Free

3) hit ^C before situation becomes too bad; and wait some time before
   recover.
Memory: 8224K Act, 2428K Inact, 4084K Wired, 3204K Exec, 4364K File, 5584K Free
Swap: 4096M Total, 24M Used, 4072M Free

Looks like viaide is not the culprit, sorry.

-- 
Nicolas Joly

Biological Software and Databanks.
Institut Pasteur, Paris.