Re: [PATCH 5/7] KVM-GST: KVM Steal time accounting

[Peter Zijlstra]

On Tue, 2011-06-14 at 22:08 -0300, Glauber Costa wrote:
> >> +               while (steal>  TICK_NSEC) {
> >
> >                       /* really, if we wanted a division we'd have
> written one */
> >                       asm("" : "+rm" (steal));
> 
> Out of curiosity, have we seen any compiler de-optimize it to a 
> division, or are you just being careful ?
> 
> >> +                       steal -= TICK_NSEC;
> >> +                       st++;
> >> +               } 

No that really happened a number of times, there's one in
sched_avg_period() that actually triggered and __iter_div_u64_rem() that
started it all iirc.
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