Messages in this thread | | | Date | Fri, 11 Jan 2008 09:02:46 -0800 (PST) | From | dean gaudet <> | Subject | Re: CPA patchset |
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On Fri, 11 Jan 2008, Ingo Molnar wrote:
> * Andi Kleen <ak@suse.de> wrote: > > > Cached requires the cache line to be read first before you can write > > it. > > nonsense, and you should know it. It is perfectly possible to construct > fully written cachelines, without reading the cacheline first. MOVDQ is > SSE1 so on basically in every CPU today - and it is 16 byte aligned and > can generate full cacheline writes, _without_ filling in the cacheline > first.
did you mean to write MOVNTPS above?
> Bulk ops (string ops, etc.) will do full cacheline writes too, > without filling in the cacheline.
on intel with fast strings enabled yes. mind you intel gives hints in the documentation these operations don't respect coherence... and i asked about this when they posted their memory ordering paper but got no response.
-dean
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