Re: [patch v5 06/15] sched: log the cpu utilization at rq

Alex Shi
2013-02-21T01:35:30Z

On 02/20/2013 11:20 PM, Peter Zijlstra wrote:
> On Wed, 2013-02-20 at 22:33 +0800, Alex Shi wrote:
>>> There's generally a better value than 100 when using computers..
>> seeing
>>> how 100 is 64+32+4.
>>
>> I didn't find a good example for this. and no idea of your suggestion,
>> would you like to explain a bit more?
>
> Basically what you're doing ends up being fixed point math, using 100 as
> unit is inefficient, pick a power-of-2 and everything reduces to
> bit-shifts.
>
> http://en.wikipedia.org/wiki/Fixed-point_arithmetic
>
> So use 128 or 1024 or whatever and you don't need mult and div
> instructions to represent [0,1]
>

got it. will reconsider this.

--
Thanks Alex