Re: [PATCH -mm 0/4] x86_64 boot: Add linked listof struct setup_data to boot protocol

[Ingo Molnar <mingo@elte.hu>]

* Huang, Ying <ying.huang@intel.com> wrote:

> This patchset adds the linked list of struct setup_data to boot 
> protocol. This is needed by EDD information and some SGI machine with 
> E820 entry number > 128.

what happens with the SGI machine - does it crash (because we overflow 
the e820 array) - or does it boot up with less memory available and we 
get this bootup warning:

    Ooops! Too many entries in the memory map!

?

I guess we should we raise E820MAX from 128 to 256 (patch below), but if 
we do something worse (crash), we should fix that side-effect as well.

> Now, only the x86_64 is supported. The i386 can be supported after 
> early reservation mechanism for x86 is available.

could you try to do that nevertheless? We generally prefer feature 
patches after sensible unification has been done.

	Ingo

-------------->
Subject: x86: more e820
From: Ingo Molnar <mingo@elte.hu>
Date: Thu Mar 27 09:18:44 CET 2008

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 include/asm-x86/e820.h |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Index: linux-x86.q/include/asm-x86/e820.h
===================================================================
--- linux-x86.q.orig/include/asm-x86/e820.h
+++ linux-x86.q/include/asm-x86/e820.h
@@ -1,8 +1,9 @@
 #ifndef __ASM_E820_H
 #define __ASM_E820_H
-#define E820MAP	0x2d0		/* our map */
-#define E820MAX	128		/* number of entries in E820MAP */
-#define E820NR	0x1e8		/* # entries in E820MAP */
+
+#define E820MAP		0x2d0		/* our map */
+#define E820MAX		256		/* number of entries in E820MAP */
+#define E820NR		0x1e8		/* # entries in E820MAP */
 
 #define E820_RAM	1
 #define E820_RESERVED	2