From the upstream patch:
"Symptom will either be memory corruption or MCA."
This is needed on some 64-bit machines from HP, ia64 machines in particular.
Created attachment 129333 [details]
HP is reporting data (memory) corruption on two Montecito platforms they plan to
launch just after U4 in early August.
Per the developer of the patch (Grant Grundler), the patch is approved upstream
and considered necessary by both the maimtainer (Greg Kroah-Hartman) and the
maintainer for Infiniband (which was our primary concern). This patch only
affects platforms with 64-bit firmware and is required for all PCI-X and PCI-e
committed in stream U4 build 39.2. A test kernel with this patch is available
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.