lkml.org 
[lkml]   [2012]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 09/16] sched: normalize tg load contributions against runnable time
From
Date
On Wed, 2012-06-27 at 19:24 -0700, Paul Turner wrote:

> + contrib = div_u64(sa->runnable_avg_sum << 12,
> + sa->runnable_avg_period + 1);

> +
> + /*
> + * Unlike a task-entity, a group entity may be using >=1 cpu globally.
> + * However, in the case that it's using <1 cpu we need to form a
> + * correction term so that we contribute the same load as a task of
> + * equal weight. (Global runnable time is taken as a fraction over
> + * 2^12.)
> + */
> + runnable_avg = atomic_read(&tg->runnable_avg);
> + if (runnable_avg < (1<<12)) {
> + se->avg.load_avg_contrib *= runnable_avg;
> + se->avg.load_avg_contrib /= (1<<12);
> + }


Did we really have to open-code a 4096 fixed point here? Couldn't we
re-use some of the existing _SCALE things.. if not why 12?




\
 
 \ /
  Last update: 2012-07-06 15:01    [W:0.231 / U:31.220 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site