Messages in this thread | | | Subject | Re: Athlon fast_copy_page revisited | From | Gordon Sadler <> | Date | Sat, 02 Jun 2001 12:38:31 -0500 |
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[This message has also been posted.] On Wed, 30 May 2001 18:09:35 GMT, Jimmie Mayfield <mayfield+kernel@sackheads.org> wrote: <SNIP explanation> > Arjan's original code is at: http://www.fenrus.demon.nl/athlon.c > My modifications are at: http://sackheads.org/~mayfield/jrm_athlon.c > > Example test runs: > > copy_page() tests > copy_page function 'warm up run' took 21350 cycles per page > copy_page function '2.4 non MMX' took 27706 cycles per page > copy_page function '2.4 MMX fallback' took 28600 cycles per page > copy_page function '2.4 MMX version' took 21370 cycles per page > copy_page function 'faster_copy' took 13119 cycles per page > copy_page function 'even_faster' took 14767 cycles per page > copy_page function 'jrm_copy_page_8nop' took 12774 cycles per page > copy_page function 'jrm_copy_page_10nop' took 12746 cycles per page > copy_page function 'jrm_copy_page_12nop' took 12740 cycles per page > > copy_page() tests > copy_page function 'warm up run' took 22499 cycles per page > copy_page function '2.4 non MMX' took 27769 cycles per page > copy_page function '2.4 MMX fallback' took 27696 cycles per page > copy_page function '2.4 MMX version' took 22666 cycles per page > copy_page function 'faster_copy' took 13058 cycles per page > copy_page function 'even_faster' took 13169 cycles per page > copy_page function 'jrm_copy_page_8nop' took 12691 cycles per page > copy_page function 'jrm_copy_page_10nop' took 12750 cycles per page > copy_page function 'jrm_copy_page_12nop' took 14786 cycles per page > > The values obviously fluctuate depending on system activity but the jrm_* > routines were faster in 13 out of 15 trials. > I have a Duron 800 socket A on an Epox 8KTA3. Has anyone noticed fluctuations with these tests.. such as jrm_athlon1: ... copy_page function 'faster_copy' took 9869 cycles per page copy_page function 'even_faster' took 9822 cycles per page ... jrm_athlon2: ... copy_page function 'faster_copy' took 9939 cycles per page copy_page function 'even_faster' took 17728 cycles per page ... jrm_athlon3: ... copy_page function 'faster_copy' took 17711 cycles per page copy_page function 'even_faster' took 9843 cycles per page ...
I see these with gcc 2.95.4(Debian unstable) and a local build of gcc-3.0 from CVS last night.
Almost as though some stall and/or caching is corrupting the results.
-- Gordon Sadler
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