Re: [RFC][PATCH 13/16] sched: Add core wide task selection and scheduling.

[Subhra Mazumdar]

On 4/19/19 1:40 AM, Ingo Molnar wrote:
> * Subhra Mazumdar <subhra.mazumdar@xxxxxxxxxx> wrote:
>
> > I see similar improvement with this patch as removing the condition I
> > earlier mentioned. So that's not needed. I also included the patch for the
> > priority fix. For 2 DB instances, HT disabling stands at -22% for 32 users
> > (from earlier emails).
> >
> >
> > 1 DB instance
> >
> > users baseline %idle core_sched %idle
> > 16ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂ 84ÂÂÂÂÂÂ -4.9% 84
> > 24ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂ 76ÂÂÂÂÂÂ -6.7% 75
> > 32ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂ 69ÂÂÂÂÂÂ -2.4% 69
> >
> > 2 DB instance
> >
> > users baseline %idle core_sched %idle
> > 16ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂ 66ÂÂÂÂÂÂ -19.5% 69
> > 24ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂ 54ÂÂÂÂÂÂ -9.8% 57
> > 32ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂ 42ÂÂÂÂÂÂ -27.2%ÂÂÂÂÂÂÂ 48
> So HT disabling slows down the 2DB instance by -22%, while core-sched
> slows it down by -27.2%?
>
> Would it be possible to see all the results in two larger tables (1 DB
> instance and 2 DB instance) so that we can compare the performance of the
> 3 kernel variants with each other:
>
>   - "vanilla +HT": Hyperthreading enabled,  vanilla scheduler
>   - "vanilla -HT": Hyperthreading disabled, vanilla scheduler
>   - "core_sched":  Hyperthreading enabled,  core-scheduling enabled
>
> ?
>
> Thanks,
>
> 	Ingo
Following are the numbers. Disabling HT gives improvement in some cases.

1 DB instance

users vanilla+HT core_sched vanilla-HT
16ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂÂÂ -4.9% -11.7%
24ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂÂÂ -6.7% +13.7%
32ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂÂÂ -2.4% +8%

2 DB instance

users vanilla+HT core_sched vanilla-HT
16ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂÂÂ -19.5% +5.6%
24ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂÂÂ -9.8% +3.5%
32ÂÂÂÂ 1ÂÂÂÂÂÂÂÂÂÂÂ -27.2%ÂÂÂÂÂÂÂ -22.8%