Messages in this thread | | | Date | Fri, 29 Apr 2016 04:34:05 +0800 | From | Yuyang Du <> | Subject | Re: [PATCH v3 6/6] sched/fair: Move (inactive) option from code to config |
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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.
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