Re: [git pull] scheduler fixes

Ingo Molnar
2008-05-11T14:32:57Z

* Matthew Wilcox <matthew@wil.cx> wrote:

> > the gain is rather obvious: two parallel up()s (or just up()s which
> > come close enough after each other) will wake up two tasks in
> > parallel. With your patch, the first guy wakes up and then it wakes
> > up the second guy. I.e. your patch serializes the wakeup chain, mine
> > keeps it parallel.
>
> Yup. I explained why that's actually beneficial in an earlier email.

but the problem is that by serializing the wakeup chains naively you
introduced a more than 50% AIM7 performance regression.

Ingo