[CentOS] pagecache corruption on Tyan S3870

[Dan Halbert]

Dan Halbert wrote:
> A couple of months ago I reported some problems with a batch of Tyan K8SSA (S3870) based machines.
>...
> The symptom is that some large (700MB to >1GB) files opened for read and 
> then closed show corruption in the pagecache. One or more 4k blocks in a 
> file will be completely trashed...
> A reboot or a flush of the pagecache fixes the problem, 
> so it's only in the pagecache, not on disk.

One more followup on this, for posterity. (I don't like unanswered questions in mailing-list archives.) It turns out this problem seems to be the same one reported in this kernel bug: http://bugzilla.kernel.org/show_bug.cgi?id=7768. It has also been discussed on LKML.

The bug was reported on AMD Nvidia boards; we have AMD ServerWorks, but the problem aooears to be the same. AMD is working on this. The current workaround is to boot with "iommu=soft".

Dan