Messages in this thread | | | Date | Mon, 26 Nov 2007 23:12:52 -0500 | From | John Richard Moser <> | Subject | Re: [rfc 08/45] cpu alloc: x86 support |
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Andi Kleen wrote: > On Tuesday 20 November 2007 04:50, Christoph Lameter wrote: >> On Tue, 20 Nov 2007, Andi Kleen wrote:
> You could in theory move the modules, but then you would need to implement > a full PIC dynamic linker for them first and also increase runtime overhead > for them because they would need to use a GOT/PLT.
On x86-64? The GOT/PLT should stay in cache due to temporal locality. The x86-64 instruction set itself handles GOT-relative addressing rather well; what's a 1% loss on x86 is like 0.01% on x86-64, so I'm thinking 100 times better?
I think I got this by `-fpic -pie` compiling nbyte benchmark versus fixed position, each with and without on 32-bit (which made about a 1% difference) and on 64-bit (which made a 0.01% difference). It was a long time ago.
Still, yeah I know. Complexity.
(You have the ability to textrel these things too, and just rewrite non-PIC, depending on how you feel about that) -- Bring back the Firefox plushy! http://digg.com/linux_unix/Is_the_Firefox_plush_gone_for_good https://bugzilla.mozilla.org/show_bug.cgi?id=322367 - 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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