Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1390722 > unrolled thread

Re: [PATCH v3 6/6] sched/fair: Move (inactive) option from code to config

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [PATCH v3 6/6] sched/fair: Move (inactive) option from code to  config Yuyang Du <yuyang.du@intel.com> - 2016-04-29 06:20 +0200

#1390722 — Re: [PATCH v3 6/6] sched/fair: Move (inactive) option from code to config

On Thu, Apr 28, 2016 at 11:37:33AM +0200, Peter Zijlstra wrote:
> On Tue, Apr 05, 2016 at 12:12:31PM +0800, Yuyang Du wrote:
> > The option of increased load resolution (fixed point arithmetic range) is
> > unconditionally deactivated with #if 0. But since it may still be used
> > somewhere (e.g., in Google), we want to keep this option.
> > 
> > Regardless, there should be a way to express this option. Considering the
> > current circumstances, the reconciliation is we define a config
> > CONFIG_CFS_INCREASE_LOAD_RANGE and it depends on FAIR_GROUP_SCHED and
> > 64BIT and BROKEN.
> > 
> > Suggested-by: Ingo Molnar <mingo@kernel.org>
> 
> So I'm very tempted to simply, unconditionally, reinstate this larger
> range for everything CONFIG_64BIT && CONFIG_FAIR_GROUP_SCHED.
> 
> There was but the single claim on increased power usage, nobody could
> reproduce / analyze and Google has been running with this for years now.
> 
> Furthermore, it seems to be leading to the obvious problems on bigger
> machines where we basically run out of precision by the sheer number of
> cpus (nr_cpus ~ SCHED_LOAD_SCALE and stuff comes apart quickly).
 
Great.

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web