Re: Linux 2.6.30-rc8 [also: VIA Support]

["Michael S. Zick" <lkml@morethan.org>]

On Thu June 4 2009, Linus Torvalds wrote:
> 
> On Thu, 4 Jun 2009, Duane Griffin wrote:
> > 
> > There have been reports of hangs on various VIA C7 machines going back
> > a year now. The version of the kernel doesn't seem to matter, but the
> > version of glibc does. Unfortunately there hasn't been much progress
> > in getting to the bottom of it.
> > 
> > See here (and other linked reports):
> > http://bugs.gentoo.org/show_bug.cgi?id=228263
> 
> Hmm. That looks like a CPU problem, but hey, it might be that the glibc 
> version thing is just coincidence, and just changes timings or whatever, 
> and the problem is in the chipsets.
> 
> So at least from that particular report it smells very much 
> non-kernel-related.
> 
> That said, even if it isn't kernel-related, it might be fixable with some 
> kernel patch that changes the setup of the CPU/chipset. But we'd need VIA 
> to help with anythign like that.
> 

That is one of my pending questions - -
(It is included as a comment at the appropriate point in my patchset.)

The VIA processors have MCR's not MTRR's - -
The C7-M processor uses "in-order retirement" not "out-of-order" - -
I think the MCR's **should not** be set for "weak ordered writes" -

_But_ until I hear the recommendation of the Silicon Growers department...

Mike

> 			Linus
> 
>