Re: [PATCH] The idle notifier chain should be atomic

[Alan Stern]

On Fri, 24 Feb 2006, Andi Kleen wrote:

> On Friday 24 February 2006 04:24, Alan Stern wrote:
>  
> > In do_IRQ() there's a call to exit_idle(), which calls __exit_idle(), 
> > which runs the idle_notifier call chain.  Surely you're not saying that we 
> > can do a down_read() in this pathway?
> 
> No, but not because it's in an interrupt but because sleeping in the idle
> task is illegal.

Well, either reason is sufficient justification for making idle_notifier 
an atomic chain.

> > And actually the chain's type doesn't seem to make much difference, since
> > at the moment there's nothing in the vanilla kernel that registers for the
> > idle_notifier chain.
> 
> Will come eventually.

Will that be just for x86_64 or for all architectures?

Alan Stern

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