How does x86 pause instruction work in spinlock *and* can it be used in other scenarios?

Question

The pause instruction is commonly used in the loop of testing spinlock, when some other thread owns the spinlock, to mitigate the tight loop. It\'s said that it

Answer 1

A processor suffers a severe performance penalty when exiting the loop because it detects a possible memory order violation. The PAUSE instruction provides a hint to the processor that the code sequence is a spin-wait loop. The processor uses this hint to avoid the memory order violation in most situations, which greatly improves processor performance. For this reason, it is recommended that a PAUSE instruction be placed in all spin-wait loops. An additional function of the PAUSE instruction is to reduce the power consumed by Intel processors.

[source: Intel manual]