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 <axb...@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)