Re: [PATCH v2 3/3] sched: increase SCHED_LOAD_SCALE resolution

From: Ingo Molnar
Date: Wed May 18 2011 - 14:26:14 EST



* Nikhil Rao <ncrao@xxxxxxxxxx> wrote:

> /*
> - * Increase resolution of nice-level calculations:
> + * Increase resolution of nice-level calculations for 64-bit architectures.
> */
> -#define SCHED_LOAD_SHIFT 10
> +#if BITS_PER_LONG > 32
> +#define SCHED_LOAD_RESOLUTION 10
> +#define scale_load(w) (w << SCHED_LOAD_RESOLUTION)
> +#define scale_load_down(w) (w >> SCHED_LOAD_RESOLUTION)
> +#else
> +#define SCHED_LOAD_RESOLUTION 0
> +#define scale_load(w) w
> +#define scale_load_down(w) w
> +#endif

Please also be a bit more verbose in the comment above why we treat 64-bit
architectures differently - it's not obvious.

Thanks,

Ingo
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