CentOS IOMMU related errors on system boot
From Notes_Wiki
<yambe:breadcrumb>CentOS|CentOS</yambe:breadcrumb>
On booting CentOS, RHEL or Fedora it is possible to receive large number of messages of
PTE read access is not set
This is caused by some problem with IOMMU unit. This can be avoided (not solved) by disabling IOMMU altogether. This requires editing /etc/grub/grub.conf file and removing
intel_iommu=on amd_iommu=on
options.
Note that ignoring these message flooding is not a good idea. This will cause /var/log/messages flie to become very big, system to be very slow due to continuous disk write of these log messages and would make debugging things that require /var/log/messages to be read very difficult.
This was learned from http://www.gossamer-threads.com/lists/linux/kernel/1647852
