From: Jens Axboe <axboe@suse.de>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@osdl.org>, Linus Torvalds <torvalds@osdl.org>
Subject: 2G memory split
Date: Tue, 10 Jan 2006 13:58:53 +0100 [thread overview]
Message-ID: <20060110125852.GA3389@suse.de> (raw)
Hi,
It does annoy me that any 1G i386 machine will end up with 1/8th of the
memory as highmem. A patch like this one has been used in various places
since the early 2.4 days at least, is there a reason why it isn't merged
yet? Note I just hacked this one up, but similar patches abound I'm
sure. Bugs are mine.
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index d849c68..0b2457b 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -444,6 +464,24 @@ config HIGHMEM64G
endchoice
+choice
+ depends on NOHIGHMEM
+ prompt "Memory split"
+ default DEFAULT_3G
+ help
+ Select the wanted split between kernel and user memory. On a 1G
+ machine, the 3G/1G default split will result in 128MiB of high
+ memory. Selecting a 2G/2G split will make all of memory available
+ as low memory. Note that this will make your kernel incompatible
+ with binary only kernel modules.
+
+ config DEFAULT_3G
+ bool "3G/1G user/kernel split"
+ config DEFAULT_2G
+ bool "2G/2G user/kernel split"
+
+endchoice
+
config HIGHMEM
bool
depends on HIGHMEM64G || HIGHMEM4G
diff --git a/include/asm-i386/page.h b/include/asm-i386/page.h
index 73296d9..be5f6b6 100644
--- a/include/asm-i386/page.h
+++ b/include/asm-i386/page.h
@@ -110,10 +110,22 @@ extern int page_is_ram(unsigned long pag
#endif /* __ASSEMBLY__ */
#ifdef __ASSEMBLY__
+#if defined(CONFIG_DEFAULT_3G)
#define __PAGE_OFFSET (0xC0000000)
+#elif defined(CONFIG_DEFAULT_2G)
+#define __PAGE_OFFSET (0x80000000)
+#else
+#error" Bad memory split"
+#endif
#define __PHYSICAL_START CONFIG_PHYSICAL_START
#else
+#if defined(CONFIG_DEFAULT_3G)
#define __PAGE_OFFSET (0xC0000000UL)
+#elif defined(CONFIG_DEFAULT_2G)
+#define __PAGE_OFFSET (0x80000000UL)
+#else
+#error "Bad memory split"
+#endif
#define __PHYSICAL_START ((unsigned long)CONFIG_PHYSICAL_START)
#endif
#define __KERNEL_START (__PAGE_OFFSET + __PHYSICAL_START)
--
Jens Axboe
next reply other threads:[~2006-01-10 12:57 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-10 12:58 Jens Axboe [this message]
2006-01-10 13:29 ` 2G memory split Ingo Molnar
2006-01-10 13:37 ` Jens Axboe
2006-01-10 13:43 ` Byron Stanoszek
2006-01-10 13:47 ` Jens Axboe
2006-01-10 14:39 ` Jens Axboe
2006-01-10 14:44 ` Ingo Molnar
2006-01-10 15:03 ` [PATCH] Address space split configuration Jens Axboe
2006-01-10 15:11 ` Mark Lord
2006-01-10 15:24 ` Mikael Pettersson
2006-01-10 16:14 ` 2G memory split Linus Torvalds
2006-01-10 16:40 ` Mark Lord
2006-01-10 16:52 ` Linus Torvalds
2006-01-10 18:33 ` Coywolf Qi Hunt
2006-01-10 17:07 ` Mark Lord
2006-01-10 17:28 ` Linus Torvalds
2006-01-10 17:32 ` Jens Axboe
2006-01-10 17:37 ` Mark Lord
2006-01-10 18:58 ` Mark Lord
2006-01-10 19:16 ` [PATCH ] VMSPLIT config options (with default config fixed) Mark Lord
2006-01-10 17:37 ` Jeff V. Merkey
2006-01-10 19:27 ` Jens Axboe
2006-01-11 1:13 ` J.A. Magallon
2006-01-11 10:15 ` Jens Axboe
2006-01-11 16:00 ` Greg Norris
2006-01-11 17:13 ` Mark Lord
2006-01-11 17:44 ` Greg Norris
2006-02-05 18:42 ` Barry K. Nathan
2006-02-01 22:23 ` Herbert Poetzl
2006-02-02 11:04 ` Ulrich Mueller
2006-02-02 20:55 ` Jan Engelhardt
2006-02-03 22:39 ` Mark Lord
2006-02-04 10:23 ` Ulrich Mueller
2006-02-04 11:06 ` Jan Engelhardt
2006-02-04 10:36 ` Jens Axboe
2006-02-04 11:05 ` Jan Engelhardt
2006-02-04 13:57 ` Mark Lord
2006-02-05 15:32 ` J.A. Magallon
2006-02-05 15:38 ` Arjan van de Ven
2006-02-05 21:14 ` Jan Engelhardt
2006-02-05 21:19 ` Arjan van de Ven
2006-02-06 14:56 ` Jan Engelhardt
2006-02-07 0:41 ` Herbert Poetzl
2006-02-07 2:51 ` Mark Rustad
2006-02-07 9:38 ` Bernd Petrovitsch
2006-02-07 12:19 ` RFC: add an ADVANCED_USER option Adrian Bunk
2006-02-07 14:05 ` Ulrich Mueller
2006-02-07 14:42 ` Adrian Bunk
2006-02-09 16:06 ` Jan Engelhardt
2006-01-10 17:48 ` 2G memory split Bernd Eckenfels
2006-01-10 16:30 ` [PATCH] " Jeff V. Merkey
2006-01-10 18:50 ` Lennart Sorensen
2006-01-10 17:13 ` Jeff V. Merkey
2006-01-10 19:42 ` Jens Axboe
2006-01-10 20:17 ` Bernd Eckenfels
2006-01-10 20:28 ` Jens Axboe
2006-01-11 8:39 ` Bernd Eckenfels
2006-01-11 10:06 ` Jens Axboe
2006-01-10 18:14 ` Martin Bligh
2006-01-10 18:34 ` Linus Torvalds
2006-01-10 16:56 ` Jeff V. Merkey
2006-01-10 17:01 ` Jeff V. Merkey
2006-01-10 18:45 ` Mark Lord
2006-01-10 18:46 ` Martin Bligh
2006-01-10 18:58 ` Jens Axboe
2006-01-10 17:17 ` Jeff V. Merkey
2006-01-10 20:55 ` Alan Cox
2006-01-10 19:12 ` Jeff V. Merkey
2006-01-10 21:02 ` Jens Axboe
2006-01-10 19:30 ` Jeff V. Merkey
2006-01-10 18:39 ` Martin Bligh
2006-01-10 18:55 ` Dave Hansen
2006-01-10 19:01 ` Mark Lord
2006-01-10 19:05 ` Dave Hansen
2006-01-10 17:07 ` Sergey Vlasov
2006-04-10 14:11 ` Kirill Korotaev
2006-04-10 14:39 ` Mark Lord
2006-01-10 18:28 ` Coywolf Qi Hunt
2006-01-10 13:47 ` Mikael Pettersson
2006-01-10 13:54 ` Jens Axboe
2006-01-10 14:09 ` Gerd Hoffmann
2006-01-10 14:21 ` Jens Axboe
2006-01-10 14:25 ` Jens Axboe
2006-01-10 20:42 ` Jan Engelhardt
2006-01-11 0:25 ` Con Kolivas
2006-01-10 14:12 ` Mark Lord
2006-01-10 14:22 ` Jens Axboe
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