Re: [PATCH 0/4] sched/fair: Improve fairness between cfs tasks

From: Phil Auld
Date: Fri Sep 18 2020 - 12:39:41 EST


Hi Peter,

On Mon, Sep 14, 2020 at 01:42:02PM +0200 peterz@xxxxxxxxxxxxx wrote:
> On Mon, Sep 14, 2020 at 12:03:36PM +0200, Vincent Guittot wrote:
> > Vincent Guittot (4):
> > sched/fair: relax constraint on task's load during load balance
> > sched/fair: reduce minimal imbalance threshold
> > sched/fair: minimize concurrent LBs between domain level
> > sched/fair: reduce busy load balance interval
>
> I see nothing objectionable there, a little more testing can't hurt, but
> I'm tempted to apply them.
>
> Phil, Mel, any chance you can run them through your respective setups?
>

Sorry for the delay. Things have been backing up...

We tested with tis series and found there was no performance change in
our test suites. (We don't have a good way to share the actual numbers
outside right now, but since they aren't really different it probably
doesn't matter much here.)

The difference we did see was a slight decrease in the number of tasks
moved around at higher loads. That seems to be a good thing even though
it didn't directly show time-based performance benefits (and was pretty
minor).

So if this helps other use cases we've got no problems with it.

Thanks,
Phil

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