Messages in this thread |  | | Date | Wed, 19 Sep 2001 15:21:21 -0400 | From | Arjan van de Ven <> | Subject | Re: [PATCH] Athlon bug stomper. Pls apply. |
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On Wed, Sep 19, 2001 at 09:15:17PM +0000, Petr Vandrovec wrote: > On 19 Sep 01 at 19:55, Arjan van de Ven wrote: > > > > Ok but that part is simple: > > > > run > > > > http://www.fenrus.demon.nl/athlon.c > > Small question - is it OK that 'faster_copy' is faster than > 'even_faster'?
Yeah; both are "new style" with a minor variation, "even_faster" is basically my test victim, and faster_ is the "last known good" one.
> clear_page function '2.4 MMX version' took 8508 cycles per page > clear_page function 'faster_clear_page' took 4016 cycles per page > clear_page function 'even_faster_clear' took 3916 cycles per page
Yup, > 2x improvement, that's expected
> > copy_page() tests > copy_page function '2.4 MMX version' took 15163 cycles per page > copy_page function 'faster_copy' took 8569 cycles per page > copy_page function 'even_faster' took 8805 cycles per page
same here
If it were only 5%, I would vote for disabling the optimisation given the number of problems; however it's 2x _and_ you can trigger the bug as normal user from userspace too... so we need to fix the hardware/bios.
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