Re: [tip:sched/eevdf] [sched/fair] e0c2ff903c: phoronix-test-suite.blogbench.Write.final_score -34.8% regression

From: Peter Zijlstra
Date: Tue Aug 15 2023 - 19:53:17 EST


On Mon, Aug 14, 2023 at 08:32:55PM +0200, Mike Galbraith wrote:

> I don't have that phoronix thingy, but the above didn't seem to do
> anything for hackbench here.

Yeah, looking at it this is because the lag and the request/slice are on
the same order of things.

More thinking required, but perhaps not at 2am.

> I whack eevdf with the stick below to dampen its scheduling enthusiasm
> a little, and it did help the hackbench deficit some.

I'm thinking there's an argument to be had the current WAKEUP_PREEMPTION
knob is at the wrong place and should be more or less where you put the
triddle at.