系统：CentOS 6.2 X86_64
内核：2.6.32-220.el6.x86_64
硬件：Dell PowerEdge R420
CPU：Intel(R) Xeon(R) CPU E5-2420 0 @ 1.90GHz
详细错误信息如下：
WARNING: at drivers/pci/intr_remapping.c:715 enable_intr_remapping+0×73/0x2af() (Not tainted)
Hardware name: PowerEdge R420
Your BIOS has requested that x2apic be disabled.
This will leave your machine vulnerable to irq-injection attacks.
Use ‘intremap=no_x2apic_optout’ to override BIOS request.
解决：
因ROM默认情况下不使用x2apic
1.忽略
2.使用’intremap=no_x2apic_optout’ 内核选项进行启动
如：
# vim /boot/grub/grub.conf
title CentOS (2.6.32-220.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-220.el6.x86_64 ro root=/dev/mapper/VolGroup00-LogVol00_root rd_NO_LUKS rd_LVM_LV=VolGroup00/LogVol01_swap LANG=en_US.UTF-8 rd_NO_MD quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_LVM_LV=VolGroup00/LogVol00_root KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM intremap=no_x2apic_optout #添加该参数，重启服务器解决
initrd /initramfs-2.6.32-220.el6.x86_64.img