[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Sat, 11 Oct 2008 00:57:03 +0200
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: Ingo Molnar <mingo@...e.hu>
Cc: Dave Hansen <dave@...ux.vnet.ibm.com>,
"Serge E. Hallyn" <serue@...ibm.com>,
containers@...ts.linux-foundation.org, arnd@...db.de,
linux-kernel@...r.kernel.org,
Arjan van de Ven <arjan@...radead.org>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
ACPI Devel Maling List <linux-acpi@...r.kernel.org>
Subject: Re: [RFC][PATCH 2/2] first callers of process_deny_checkpoint()
On Friday, 10 of October 2008, Ingo Molnar wrote:
>
> * Rafael J. Wysocki <rjw@...k.pl> wrote:
>
> > > > Surely not ACPI-compliant.
> > >
> > > what do you mean?
> >
> > The ACPI spec says quite specifically what should be done while
> > entering hibernation and during resume from hibernation. We're not
> > following that in the current code, but we can (gradually) update the
> > code to become ACPI-compilant in that respect. However, if we go the
> > checkpointing route, I don't think that will be possible any more.
>
> ah, i see. I did not mean to utilize any ACPI paths but simple powerdown
> or reboot.
>
> If we checkpoint all apps to persistent disk areas (which the checkpoint
> patches in this thread are about), then we can just reboot the kernel
> and forget all its state.
>
> That capability can be used to build a really robust hibernation
> implementation IMO: we could "hibernate/kexec" over between different
> kernel versions transparently. (only a small delay will be noticed by
> the user - if we do it smartly with in-kernel modesetting then not even
> the screen contents will be changed over this.)
That actually should be called a migration of VM IMO and would be a useful
functionality. Sure.
Hibernation, however, generally involves the restoration of the hardware and
most importantly _platform_ state which IMO is impossible without the ACPI
functionality, as well as wake-up, which may depend on ACPI too.
Thanks,
Rafael
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists