> I get: > > mov %gs:0x18(%rax),%rdx > > Looks to me that %gs is used. %gs is used as a segment prefix. That does not add significant cycles. Retrieving the content of %gs and loading it into another register would be expensive in terms of cpu cycles. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>