Re: Silent data corruption caused by XPC.

[Robin Holt <holt@sgi.com>]

On Mon, Aug 07, 2006 at 08:57:51AM -0700, Luck, Tony wrote:
> > and verified it works.  I also added DBUG_ON statements to help catch
> > this if a similar situation is encountered.
> 
> Can you just do this once at alloc time rather than at every use?

Dean and I liked the idea at first, but hashed it over more.  My intent
with putting them right before the bte_copy was to trap the event where
a copy was going to be initiated that would corrupt memory.  If I put
them at allocation time only, any changes in the allocation would not
necessarily be caught.  I think we would like to leave them where they
are at unless you have a strong objection.  They are DBUG_ON() instead
of BUG_ON() so they should not have a performance impact normally.

If you would like it moved to allocation time, it will make
the patch smaller and more clean as we will move it into
xpc_kmalloc_cacheline_aligned.  Dean said he will handle that if you
desire.

Thanks,
Robin