From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Machek <pavel@ucw.cz>, Andi Kleen <ak@suse.de>,
Avi Kivity <avi@qumranet.com>,
Glauber de Oliveira Costa <gcosta@redhat.com>,
linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
glommer@gmail.com, tglx@linutronix.de, ehabkost@redhat.com,
jeremy@goop.org, anthony@codemonkey.ws,
virtualization@lists.linux-foundation.org, rusty@rustcorp.com.au,
chrisw@sous-sol.org, rostedt@goodmis.org, hpa@zytor.com
Subject: Re: [PATCH 4/8] unify paravirt parts of system.h
Date: Mon, 17 Dec 2007 01:27:29 +0100 [thread overview]
Message-ID: <200712170127.31615.rjw@sisk.pl> (raw)
In-Reply-To: <20071215131723.GF9720@elte.hu>
On Saturday, 15 of December 2007, Ingo Molnar wrote:
>
> * Pavel Machek <pavel@ucw.cz> wrote:
>
> > > Linux never uses that register. The only user is suspend
> > > save/restore, but that' bogus because it wasn't ever initialized by
> > > Linux in the first place. It could be probably all safely removed.
> >
> > It probably is safe to remove... but we currently support '2.8.95
> > kernel loads/resumes 2.6.24 image'... which would break if 2.8 uses
> > cr8.
> >
> > So please keep it if it is not a big problem.
>
> hm, so __save_processor_state() is in essence an ABI? Could you please
> also send a patch that documents this prominently, in the structure
> itself?
Hmm, I'm not sure if it really is an ABI part. It doesn't communicate anything
outside of the kernel in which it is defined.
The problem is, though, that if kernel A is used for resuming kernel B, and
kernel B doesn't save/restore everything it will need after the resume, then
things will break if kernel A modifies that. So, yes, we'll need to document
that explicitly.
Greetings,
Rafael
next prev parent reply other threads:[~2007-12-17 0:08 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-04 16:06 [PATCH 0/8] Integrate system.h Glauber de Oliveira Costa
2007-12-04 16:06 ` [PATCH 1/8] remove volatile keyword from clflush Glauber de Oliveira Costa
2007-12-04 16:06 ` [PATCH 2/8] put together equal pieces of system.h Glauber de Oliveira Costa
2007-12-04 16:06 ` [PATCH 3/8] unify load_segment macro Glauber de Oliveira Costa
2007-12-04 16:06 ` [PATCH 4/8] unify paravirt parts of system.h Glauber de Oliveira Costa
2007-12-04 16:06 ` [PATCH 5/8] remove unused macro Glauber de Oliveira Costa
2007-12-04 16:06 ` [PATCH 6/8] unify smp parts of system.h Glauber de Oliveira Costa
2007-12-04 16:06 ` [PATCH 7/8] move switch_to macro to system.h Glauber de Oliveira Costa
2007-12-04 16:06 ` [PATCH 8/8] unify system.h Glauber de Oliveira Costa
2007-12-04 19:18 ` [PATCH 4/8] unify paravirt parts of system.h Avi Kivity
2007-12-04 19:34 ` Andi Kleen
2007-12-05 16:30 ` Pavel Machek
2007-12-15 13:17 ` Ingo Molnar
2007-12-17 0:27 ` Rafael J. Wysocki [this message]
2007-12-17 0:23 ` Pavel Machek
2007-12-17 0:58 ` Rafael J. Wysocki
2007-12-15 13:26 ` Andi Kleen
2007-12-15 22:54 ` Pavel Machek
2007-12-15 20:28 ` H. Peter Anvin
2007-12-04 19:41 ` Glauber de Oliveira Costa
2007-12-04 22:14 ` Denys Vlasenko
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