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

[Peter Zijlstra]

On Wed, Aug 16, 2023 at 11:40:33AM +0800, Chen Yu wrote:

> > Are these wakeup preemptions typically on runqueues that have only a
> > single other task?
> >
> 
> There are 112 groups of hackbench waker/wakee on a 112 CPUs system.
> Each group has 1 waker and 20 wakees. It seems that there are more than 1
> other task on each runqueue. I collected the statistics below.

Oh, I thought we were still talking about $subject benchmark. Yeah,
hackbench has a ton of tasks.


> According to above data, maybe comparing the deadline does not take much
> effect in this case(per 1). 

Yeah, I stuck a trace_printk() in last night and quicly realized the lag
is on the same order of request size, which then totally makes the whole
thing moot.