Re: [PATCH] sched/fair: Replace random newidle_balance with Bresenham accumulator

From: Qing Wang

Date: Wed May 13 2026 - 22:23:31 EST


On Wed, 13 May 2026 at 13:29, K Prateek Nayak <kprateek.nayak@xxxxxxx> wrote:
> I took the most sensitive workload I have for newidle balance (tbench)
> and took it for a spin with these changes. Following are the results:
>
> Clients: tip bresenham_accm
> 1 321.65 (0.00 pct) 313.97 (-2.38 pct)
> 2 641.92 (0.00 pct) 638.74 (-0.49 pct)
> 4 1245.65 (0.00 pct) 1237.26 (-0.67 pct)
> 8 2435.80 (0.00 pct) 2442.23 ( 0.26 pct)
> 16 4717.66 (0.00 pct) 4688.19 (-0.62 pct)
> 32 9303.53 (0.00 pct) 9390.71 ( 0.93 pct)
> 64 18002.57 (0.00 pct) 17911.56 (-0.50 pct)
> 128 27729.26 (0.00 pct) 27621.95 (-0.38 pct)
> 256 47134.77 (0.00 pct) 46137.36 (-2.11 pct)
> 512 43179.41 (0.00 pct) 43277.53 ( 0.22 pct)
> 1024 40339.30 (0.00 pct) 40176.49 (-0.40 pct)
>
> The %diff is in noise range which is a good indication that there
> shouldn't be any surprises. I'll queue a run overnight to see if
> there are other benchmarks that like / dislike these changes.
>
> I'll let Peter comment on the change itself since he knows these
> bits best ;-)

Oh! Thanks for your benchmarks :) The %diff looks good.
Let's wait for Peter's comments.

--
Best regards,
Qing