Messages in this thread | | | Subject | Re: [RFC] Documentation about unaligned memory access | From | Arne Georg Gleditsch <> | Date | Fri, 23 Nov 2007 10:46:31 +0100 |
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dean gaudet <dean@arctic.org> writes: > on AMD x86 pre-family 10h the boundary is 8 bytes, and on fam 10h it's 16 > bytes. the penalty is a mere 3 cycles if an access crosses the specified > boundary.
Worth noting though, is that atomic accesses that cross cache lines on an Opteron system is going to lock down the Hypertransport fabric for you during the operation -- which is obviously not so nice.
-- Arne. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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