Messages in this thread | | | Date | Tue, 27 Mar 2007 11:06:24 -0700 | From | "Ken Chen" <> | Subject | Re: [patch] cache pipe buf page address for non-highmem arch |
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On 27 Mar 2007 17:01:01 +0200, Andi Kleen <andi@firstfloor.org> wrote: > What is the problem? You have cache misses on the the hash table > or are the instructions really an issue on a modern CPU?
It was page_to_pfn() on numa system. I think it's cache misses on per node pgdat lookup with node index calculation on each pipe buffer page.
> e.g. i out of lined virt_to_page to save space, but it could be probably > inlined again if it was severly time critical.
That would be a problem too, though not showing up in the pipe code path. - 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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