Re: DRAM unreliable under specific access patern

From: Kirill A. Shutemov
Date: Mon Jan 05 2015 - 20:47:42 EST


On Mon, Jan 05, 2015 at 11:50:04AM -0800, Andy Lutomirski wrote:
> On Mon, Jan 5, 2015 at 11:23 AM, One Thousand Gnomes
> <gnomes@xxxxxxxxxxxxxxxxxxx> wrote:
> >> In the meantime, I created test that actually uses physical memory,
> >> 8MB apart, as described in some footnote. It is attached. It should
> >> work, but it needs boot with specific config options and specific
> >> kernel parameters.
> >
> > Why not just use hugepages. You know the alignment guarantees for 1GB
> > pages and that means you don't even need to be root
> >
> > In fact - should we be disabling 1GB huge page support by default at this
> > point, at least on non ECC boxes ?
>
> Can you actually damage anyone else's data using a 1 GB hugepage?

hugetlbfs is a filesystem: the answer is yes. Although I don't see the
issue as a big attach vector.

--
Kirill A. Shutemov
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