Re: [PATCH] Extend mwait idle to optimize away CAL and RESinterrupts to an idle CPU -v1

From: Yong Zhang
Date: Fri Feb 24 2012 - 01:14:08 EST


On Fri, Feb 24, 2012 at 01:41:50PM +0800, Yong Zhang wrote:
> On Thu, Feb 23, 2012 at 11:34:11AM -0800, Venki Pallipadi wrote:
> > On Thu, Feb 23, 2012 at 1:30 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > > Why not scheduler_ipi()?
> >
> > Was trying to avoid irq_enter/exit. As the work here is done in idle
> > thread context, I though we could avoid enter/exit.
>
> It seems we could not.
> At least RCU need it, see commit c5d753a55, otherwise we will get
> warning like 'RCU used illegally from extended quiescent state!'

[Off topic]
This remind me that we should have moved the irq_enter()/irq_exit() to
each arch's related irq handler.
see: http://marc.info/?l=linux-kernel&m=130709505700821&w=2

So Peter, is there someone alread on it? or it still worth doing now?

Thanks,
Yong
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