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SubjectRe: [PATCH] linux-2.5.67_lost-tick-fix_A2
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On Wed, 2003-04-16 at 16:03, george anzinger wrote:
> john stultz wrote:
> > Some of the divs and mods being added here might concern folks, but by
> > not calling timer->get_offset() in detect_lost_tick() we eliminate much
> > of the same math. I did some simple cycle counting and the new code
> > comes out on average equivalent or faster.
>
> I think that if you look at the generated code you may find that there
> are NO div in the asm code. The C folks know about scaling to avoid
> div especially when the divisor is a constant :)

Indeed you are correct. An objdump of both the timer_tsc.o and
timer_cyclone.o code reveals that the only divs occur in init code. I
like your argument better then mine :)

thanks
-john




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