Linux (2.6.18) hang during warm-boot test

Hi, I have a problem on warm-boot Linux.
My Linux is Red-Hat enterprise Linux version 5.0 and my CPU is Xeon
(64-bit).
On warm-boot test, my PC hangs at the following forever loop:

sti
jmp _begin_
_loop_again_:
mov rax, qword ptr gs:[0x000000010]
xor ecx, ecx
sub rax, 0x1fc8
mov rdx, rcx
monitor
mfence
mov rax, qword ptr gs:[0x000000010]
mov eax, dword ptr [rax - 0x00001fc8]
test al, 0x08
jnz _return_
mov rax, rcx
mwait
_begin_:
mov rax, qword ptr gs:[0x000000010]
mov eax, dword ptr [rax - 0x00001fc8]
test al, 0x08
jz _loop_again_
_return_:
ret

What is the meaning of "qword ptr gs:[0x000000010]" in terms of Linux
kernel ?
And what event is my PC waiting for during boot ? ( such as device
driver or something to be ready ...)

Best Regards,
Fred Lin.