On Thu 2008-01-24 16:27:58, H. Peter Anvin wrote: > Pavel Machek wrote: > >>> > >>I just looked at the ACPI suspend code, and it looks > >>like it hacks its own identity map at runtime. Pavel, > >>am I reading that code right? > > > >Yes, I think so, I believe we do it on both 32 and 64 > >bit now. > > > > So the background to this... we need an identity map to > trampoline at early boot, obviously, but we'd like it to > not stick around more than necessary. We have > zap_low_mappings() now but it's not really sufficient. > > Secondary SMP processors need these mappings during > trampolining -- presumably including CPU hotplug -- and > I'm suspecting it might simply make sense to use a > separate set of page tables (with both the identity and > the kernel map) for trampolining and just keep them > around. That way they would be usable for ACPI as well.
That would enable some cleanups, yes. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/