On Thu, 15 Jan 2015 21:57:58 -0600 (CST) Christoph Lameter <cl@xxxxxxxxx> wrote: > > 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. OK, maybe that's what I saw in my previous benchmarks. Again, that was a while ago. -- Steve -- 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>