Hello,

First I have the following hardware:
X58 Extreme6, BIOS P1.60 10/31/2011
Intel(R) Core(TM) i7 CPU 950
Kernel 3.0.6 (the bug is have can also be found on 2.6.x kernels)

When the "Intel HT Technology" feature is enable in the Bios, my kernel freeze during the boot (without any error).

After having done a lot of tests, I have found a workaround. When I boot with grub, it does not freeze when I add one of the following options:
idle=halt
idle=mwait
idle=nomwait

Well after having read the kernel documentation, I still do not know which one I should use...

idle=poll: Poll forces a polling idle loop that can slightly improve the performance of waking up a idle CPU, but will use a lot of power and make the system run hot. Not recommended.

idle=mwait: On systems which support MONITOR/MWAIT but the kernel chose to not use it because it doesn't save as much power as a normal idle loop, use the MONITOR/MWAIT idle loop anyways. Performance should be the same as idle=poll.

idle=halt: Halt is forced to be used for CPU idle. In such case C2/C3 won't be used again.

idle=nomwait: Disable mwait for CPU C-states
So which one is best option? mwait looks good but it will be removed in 2012... nomwait/halt have not a lot of description.

Any idea?

PS: I have attached my kernel configuration, maybe someone will find a workaround by finding a missing parameter in it: config.txt.gz