Re: Make yield_task_fair more efficient

[Ingo Molnar]

* Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:

> If you insist that sched_yield() is bad, I might agree, but how does 
> my patch make things worse. [...]

it puts new instructions into the hotpath.

> [...] In my benchmarks, it has helped the sched_yield case, why is 
> that bad? [...]

I had the same cache for the rightmost task in earlier CFS (it's a 
really obvious thing) but removed it. It wasnt a bad idea, but it hurt 
the fastpath hence i removed it. Algorithms and implementations are a 
constant balancing act.

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/