From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Pavel Machek <pavel@ucw.cz>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
"Jeremy Fitzhardinge" <jeremy@goop.org>,
"Ian Campbell" <ijc@hellion.org.uk>,
"Ingo Molnar" <mingo@elte.hu>,
"Mika Penttilä" <mika.penttila@kolumbus.fi>,
linux-kernel@vger.kernel.org,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH] x86: Construct 32 bit boot time page tables in native format.
Date: Fri, 25 Jan 2008 23:02:50 +0100 [thread overview]
Message-ID: <200801252302.52164.rjw@sisk.pl> (raw)
In-Reply-To: <20080125074910.GD4134@ucw.cz>
On Friday, 25 of January 2008, Pavel Machek wrote:
> 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.
Speaking of cleanups, the following one is applicable IMO.
Greetings,
Rafael
---
arch/x86/mm/init_32.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
Index: linux-2.6/arch/x86/mm/init_32.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/init_32.c
+++ linux-2.6/arch/x86/mm/init_32.c
@@ -444,23 +444,23 @@ static void __init pagetable_init (void)
paravirt_pagetable_setup_done(pgd_base);
}
-#if defined(CONFIG_HIBERNATION) || defined(CONFIG_ACPI)
+#ifdef CONFIG_SUSPEND
/*
* Swap suspend & friends need this for resume because things like the intel-agp
* driver might have split up a kernel 4MB mapping.
*/
-char __nosavedata swsusp_pg_dir[PAGE_SIZE]
+char swsusp_pg_dir[PAGE_SIZE]
__attribute__ ((aligned (PAGE_SIZE)));
static inline void save_pg_dir(void)
{
memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
}
-#else
+#else /* !CONFIG_SUSPEND */
static inline void save_pg_dir(void)
{
}
-#endif
+#endif /* !CONFIG_SUSPEND */
void zap_low_mappings (void)
{
next prev parent reply other threads:[~2008-01-25 22:05 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-19 16:08 [PATCH] x86/voyager: Switch voyager memory detection to early_ioremap Ian Campbell
2008-01-19 16:08 ` [PATCH] x86: Construct 32 bit boot time page tables in native format Ian Campbell
2008-01-19 23:07 ` Andi Kleen
2008-01-19 23:50 ` H. Peter Anvin
2008-01-20 16:44 ` Ian Campbell
2008-01-20 17:39 ` Andi Kleen
2008-01-20 18:48 ` H. Peter Anvin
2008-01-20 18:55 ` Andi Kleen
2008-01-20 18:54 ` H. Peter Anvin
2008-01-22 10:05 ` Ingo Molnar
2008-01-22 16:23 ` H. Peter Anvin
2008-01-20 18:30 ` Mika Penttilä
2008-01-21 21:23 ` Ian Campbell
2008-01-21 21:38 ` H. Peter Anvin
2008-01-21 21:46 ` Ian Campbell
2008-01-22 2:16 ` H. Peter Anvin
2008-01-22 17:36 ` Ian Campbell
2008-01-22 18:23 ` H. Peter Anvin
2008-01-22 19:48 ` Ian Campbell
2008-01-22 20:00 ` H. Peter Anvin
2008-01-22 20:36 ` Ingo Molnar
2008-01-22 20:43 ` H. Peter Anvin
2008-01-22 20:45 ` Ingo Molnar
2008-01-22 20:52 ` Ian Campbell
2008-01-22 21:00 ` H. Peter Anvin
2008-01-22 22:21 ` Ian Campbell
2008-01-22 21:00 ` [PATCH] x86: make nx_enabled conditional on CONFIG_X86_PAE Harvey Harrison
2008-01-22 21:04 ` Ingo Molnar
2008-01-22 21:35 ` Harvey Harrison
2008-01-22 21:07 ` Harvey Harrison
[not found] ` <p73odbdlyiu.fsf@crumb.suse.de>
2008-01-23 11:21 ` Harvey Harrison
2008-01-23 20:52 ` [PATCH] x86: Construct 32 bit boot time page tables in native format Ian Campbell
2008-01-24 1:06 ` Jeremy Fitzhardinge
2008-01-24 9:39 ` Ian Campbell
2008-01-24 22:06 ` H. Peter Anvin
2008-01-24 22:35 ` Jeremy Fitzhardinge
2008-01-24 22:39 ` H. Peter Anvin
2008-01-24 22:58 ` Jeremy Fitzhardinge
2008-01-24 23:08 ` H. Peter Anvin
2008-01-24 23:40 ` Jeremy Fitzhardinge
2008-01-24 23:44 ` H. Peter Anvin
2008-01-24 23:51 ` Jeremy Fitzhardinge
2008-01-25 0:02 ` H. Peter Anvin
2008-01-25 0:11 ` Jeremy Fitzhardinge
2008-01-25 0:15 ` H. Peter Anvin
2008-01-25 0:31 ` Jeremy Fitzhardinge
2008-01-25 0:37 ` H. Peter Anvin
2008-01-25 2:56 ` Eric W. Biederman
2008-01-25 4:41 ` Jeremy Fitzhardinge
2008-01-25 11:07 ` Eric W. Biederman
2008-01-24 23:51 ` H. Peter Anvin
2008-01-25 0:20 ` Pavel Machek
2008-01-25 0:27 ` H. Peter Anvin
2008-01-25 0:46 ` Rafael J. Wysocki
2008-01-25 1:08 ` H. Peter Anvin
2008-01-25 2:16 ` Eric W. Biederman
2008-01-25 2:25 ` H. Peter Anvin
2008-01-25 7:49 ` Pavel Machek
2008-01-25 22:02 ` Rafael J. Wysocki [this message]
2008-01-25 22:11 ` Pavel Machek
2008-01-28 15:00 ` Ingo Molnar
2008-01-28 15:25 ` Rafael J. Wysocki
2008-01-28 19:40 ` Pavel Machek
2008-01-28 19:51 ` H. Peter Anvin
2008-01-28 20:03 ` Jeremy Fitzhardinge
2008-01-28 20:06 ` H. Peter Anvin
2008-01-28 20:28 ` Rafael J. Wysocki
2008-01-28 20:26 ` Rafael J. Wysocki
2008-01-28 20:31 ` H. Peter Anvin
2008-01-28 20:59 ` Rafael J. Wysocki
2008-01-28 20:44 ` Jeremy Fitzhardinge
2008-01-28 20:50 ` Rafael J. Wysocki
2008-01-28 21:28 ` H. Peter Anvin
2008-01-28 22:02 ` Rafael J. Wysocki
2008-01-28 16:12 ` Ingo Molnar
2008-01-28 17:02 ` Rafael J. Wysocki
2008-02-01 13:51 ` Ingo Molnar
2008-02-01 14:28 ` Rafael J. Wysocki
2008-02-01 14:54 ` Ingo Molnar
2008-02-01 22:55 ` Len Brown
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