[CentOS] FYI - pci_mmcfg_init kernel error after upgrading to 5.6

Mon Apr 25 14:44:12 UTC 2011
Windsor Dave L. (AdP/TEF7.1) <Dave.Windsor at us.bosch.com>

On 4/25/2011 10:26 AM, Johnny Hughes wrote:
> On 04/25/2011 08:58 AM, Windsor Dave L. (AdP/TEF7.1) wrote:
>> Just thought I'd pass along an error I received this weekend after
>> upgrading two servers to 5.6.  Both are HP Proliant DL380 servers
>> running 64-bit, but one is a G6 model and one is a G7.  After the
>> upgrade and the reboot to the 2.6.18-238.9.1.el5 kernel, both servers
>> displayed the following error at boot:
>>       "pci_mmcfg_init marking 256MB space uncacheable."
>> Some Googling found me the following link:
>>       https://partner-bugzilla.redhat.com/show_bug.cgi?id=581933
>> There are apparently performance implications due to this issue.
>> Fortunately, the solution is simple:  just boot with the kernel parameter
>>       acpi_mcfg_max_pci_bus_num=on
>> If everyone is already familiar with this, please ignore. :-)
> Supposedly this issue is fixed in the 5.6 kernel ... not introduced in it :D
> https://bugzilla.redhat.com/show_bug.cgi?id=581933
> However, the advise is good regardless of version of kernel.

Yes, I saw the reference to RHEL 5.5 in the bug description, but I never 
saw the message before the upgrade to CentOS 5.6.  Hardware differences, 
I guess.  The bug description mentions a Dell Precision.

Best Regards,

Dave Windsor

Robert Bosch LLC
Team Leader, MES Database Infrastructure Group (AdP/TEF7.1)
4421 Highway 81 North
Anderson, SC 29621 USA