Re: PFs on pages pinned with get_user_pages()

From: Frank Mehnert
Date: Thu Jan 29 2009 - 11:04:21 EST


On Thursday 29 January 2009, Peter Zijlstra wrote:
> > > That aside, is there any reason you have to avoid scheduling? Otherwise
> > > I would just allow so and be done with it.
> >
> > The reason is that our code expects that to ensure syncing of the CPU
> > state with the saved state. I fear it is quite difficult to change
> > that...
>
> Ah, is that what KVM uses the preempt notifiers for? Could you too?

Right, that could be an option.

We will try to change our code which is a big effort as we try
to keep the code as unique as possible between the different
hosts we support (Linux, Solaris, Windows, Mac OS X).

Just to be sure: There is no other option than disabling interrupts
or calling disable_preemption() to prevent scheduling?

Kind regards,

Frank
--
Dr.-Ing. Frank Mehnert Sun Microsystems http://www.sun.com/

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