Re: [rfc 08/45] cpu alloc: x86 support

John Richard Moser
2007-11-27T04:19:26Z

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!