Messages in this thread |  | | Date | Fri, 22 Sep 2000 07:39:40 +0200 (CEST) | From | (Arjan van de Ven) | Subject | Re: Question: Using floating point in the kernel |
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In article <Pine.LNX.3.95.1000920141233.9629A-100000@chaos.analogic.com> you wrote: > On Wed, 20 Sep 2000, Timur Tabi wrote:
> Well the code does a fnsave. Somebody never looked at the damn book! it > takes 143 clocks for this, plus at least 3 for fwait. Then it sets a > flag to let return code 'know' if the context has to be restored. This > code `exists` sort of like moss. I don't think it is ever executed and > if it is, you get to keep both broken pieces.
+--------------------------+-------------+ | non-MMX clear_page | 2382 cycles | | MMX clear_page | 874 cycles | +--------------------------+-------------| | non-MMX copy_page | 4569 cycles | | MMX copy_page | 1748 cycles | +--------------------------+-------------+
(On a AMD Duron 700Mhz with 2 133Mhz DIMMs)
The numbers above don't include the fnsave. But as you can see the 150 cycles you mention above are still worth it.
Greetings, Arjan van de Ven
< The test program is available at http://www.fenrus.demon.nl/athlon.c > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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