Re: [git pull] scheduler fixes

Ingo Molnar
2009-01-17T16:12:50Z

* Mike Galbraith <efault@gmx.de> wrote:

> Dunno about the IO bits, but..
>
> The problem with the C++ testcases seems to be wake_up_all() plunking a
> genuine thundering herd onto runqueues. The sleeper fairness logic
> places the entire herd left of min_vruntime, meaning N*sched_latency
> pain for the poor sods who are setting the runqueue pace.

100 wakeup pairs that all run and ping-pong between each other?

That creates 200 tasks with an average system load of 100.0, on a
dual-core system. Is that a fair representation of some real workload, or
just an unrealistic "gee, look, given enough tasks running I can overload
the system _this bad_" example?

Ingo