> No. It related to the counter width. The number of bits we can use should be > 1 bit less than the total width. Otherwise, there will be problem. > For big cores such as haswell, broadwell, skylake, the counter width is 48 > bit. > So we can only use 47 bits. > For Silvermont and KNL, the counter width is only 32 bit I think. So we can > only > use 31 bits.
It is 40 bits on these cores, so 39bits. -Andi
