Re: [RFC][PATCH] irq_work

Andi Kleen
2010-06-24T11:20:44Z

On Thu, Jun 24, 2010 at 01:10:52PM +0200, Peter Zijlstra wrote:
> On Thu, 2010-06-24 at 13:08 +0200, Andi Kleen wrote:
> > > And I really want hardirq context for perf callbacks, some code actually
> > > relies on it (I used to have the fallback in the timer softirq and that
> >
> > Surely that could be fixed? *requiring* hard irq context sounds weird.
>
> possibly, but there is no reason what so ever to use softirq here.

Ok so going back to the original self-irq patchkit. Unfortunately the other
reviewer hated that. How to get out of that deadlock?

> > > broke thing at some point).
> >
> > I have one case that needs to sleep (but only when interrupting user code)
> > They key thing in it really is to switch stacks back to process.
>
> softirq can't sleep either, you need a trampoline anywa

Not true, when you interrupt ring 3 it can sleep. You just need to make
sure to run on the right stack and fix up any irq counters.

Anyways this can be solved in a different way too, it would just fit
in there too.

-Andi

--
ak@linux.intel.com -- Speaking for myself only.