Date: Thu, 24 Jun 2010 13:20:41 +0200
From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>, Huang Ying <ying.huang@intel.com>,
       Ingo Molnar <mingo@elte.hu>, "H.PeterA" <"nvin hpa"@zytor.com>,
       linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] irq_work
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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.
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