From: Marc-Christian Petersen <m.c.p@wolk-project.de>
To: linux-kernel@vger.kernel.org
Cc: Pavel Machek <pavel@ucw.cz>
Subject: Re: Highmem emulation for 2.6?
Date: Sun, 7 Mar 2004 14:19:36 +0100 [thread overview]
Message-ID: <200403071415.51065@WOLK> (raw)
In-Reply-To: <20040307125939.GA965@elf.ucw.cz>
[-- Attachment #1: Type: text/plain, Size: 175 bytes --]
On Sunday 07 March 2004 13:59, Pavel Machek wrote:
Hi Pavel,
> Does anyone have `subj`?
something like attached patch? Only for x86 now. Ontop of 2.6.4-rc1-mm2.
ciao, Marc
[-- Attachment #2: emulate-highmem-2.6.patch --]
[-- Type: text/x-diff, Size: 1361 bytes --]
--- old/include/asm-i386/setup.h 2004-02-26 01:29:43.000000000 +0100
+++ 2.6.4-rc1-mm2/include/asm-i386/setup.h 2004-03-07 14:08:33.000000000 +0100
@@ -13,7 +13,21 @@
/*
* Reserved space for vmalloc and iomap - defined in asm/page.h
*/
+#ifdef CONFIG_HIGHMEM_EMULATION
+#define ORDER_DOWN(x) ((x >> (MAX_ORDER-1)) << (MAX_ORDER-1))
+#define MAXMEM_PFN \
+({ \
+ int __max_pfn; \
+ if (max_pfn > PFN_DOWN(MAXMEM)) \
+ __max_pfn = PFN_DOWN(MAXMEM); \
+ else \
+ __max_pfn = ORDER_DOWN(max_pfn / 5); \
+ __max_pfn; \
+)}
+#else
#define MAXMEM_PFN PFN_DOWN(MAXMEM)
+#endif
+
#define MAX_NONPAE_PFN (1 << 20)
/*
--- old/arch/i386/Kconfig 2004-03-05 17:16:45.000000000 +0100
+++ 2.6.4-rc1-mm2/arch/i386/Kconfig 2004-03-07 14:11:57.000000000 +0100
@@ -773,6 +773,19 @@ config X86_PAE
depends on HIGHMEM64G
default y
+config HIGHMEM_EMULATION
+ bool ' Emulate HIGHMEM on lowmem machines'
+ depends on HIGHMEM
+ default n
+ ---help---
+ Really obvious. With this option turned on and also selecting
+ High Memory Support (4GB||64GB) you can emulate HIGHMEM on lowmem
+ mashines. This does nothing usefull, nothing speed improvement
+ or anything else but helps you to debug HIGHMEM code on lowmem
+ mashines.
+
+ If unsure, say N.
+
# Common NUMA Features
config NUMA
bool "Numa Memory Allocation Support"
prev parent reply other threads:[~2004-03-07 13:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-07 12:59 Highmem emulation for 2.6? Pavel Machek
2004-03-07 13:17 ` Michael Frank
2004-03-07 13:41 ` Michael Frank
2004-03-07 13:19 ` Marc-Christian Petersen [this message]
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