On 09/03/2009 07:59 PM, Tejun Heo wrote: > > Another question. Other than saving and loading an extra segment > register on kernel entry/exit, whether using the same or different > segment registers doesn't look like would make difference > performance-wise. If I'm interpreting the wording in the optimization > manual correctly, it means that each non-zero segment based memory > access will be costly regardless of which specific segment register is > in use and there's no way we can merge segment based dereferences for > stackprotector and percpu variables. > It's correct that it doesn't make any difference for access, only for load. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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