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    SubjectRe: [PATCH] Use x86 SSE instructions for clear_page, copy_page
    On 230, 08 17, 2004 at 09:27:51AM +0200, Arjan van de Ven wrote:
    > On Tue, 2004-08-17 at 08:13, Jens Maurer wrote:
    > > The attached patch (against kernel 2.6.8.1) enables using SSE
    > > instructions for copy_page and clear_page.
    > >
    > > A user-space test on my Pentium III 850 MHz shows a 3x speedup for
    > > clear_page (compared to the default "rep stosl"), and a 50% speedup
    > > for copy_page (compared to the default "rep movsl"). For a Pentium-4,
    > > the speedup is about 50% in both the clear_page and copy_page cases.
    >
    >
    > we used to have code like this in 2.4 but it got removed: the non
    > temperal store code is faster in a microbenchmark but has the
    > fundamental problem that it evics the data from the cpu cache; the
    > actual USE of the data thus is a LOT more expensive, result is that the
    > overall system performance goes down ;(

    Did SSE clear_page() suffered from this issue too ?

    --
    Andrey Panin | Linux and UNIX system administrator
    pazke@donpac.ru | PGP key: wwwkeys.pgp.net
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