[lkml]   [2007]   [Jun]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] x86-64: disable the GART before allocate aperture
On Fri, 22 Jun 2007 12:31:24 -0700
Muli Ben-Yehuda <> wrote:

> On Fri, Jun 22, 2007 at 12:19:15PM -0700, Yinghai Lu wrote:
> > [PATCH] x86-64: disable the GART before allocate aperture
> >
> > For K8 system: 4G RAM with memory hole remapping enabled, or more
> > than 4G RAM installed. when mem is allocated for GART, it will do
> > the memset for clear. and for kexec case, the first kernel already
> > enable that, the memset in second kernel will cause the system
> > restart. So disable that at first before we try to allocate mem for
> > it.
> Why does the memset in the second kernel cause a system restart?

You've got mapped live gart pages from the previous kernel. Even if you
disable the gart before a memset you may well have the video card using
gart translations and possibly live IOMMU mappings for devices using it
via bus mastering - and those will cause you MCE exceptions with a
corrupt cpu context flag (ie not nicely recoverable).

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-06-22 22:31    [W:0.081 / U:0.392 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site