Messages in this thread Patch in this message | | | Date | Wed, 04 Aug 2004 00:29:25 +1000 | From | Con Kolivas <> | Subject | Re: HIGHMEM4G config for 1GB RAM on desktop? |
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Jens Axboe wrote: > On Mon, Aug 02 2004, Barry K. Nathan wrote: > >>On Mon, Aug 02, 2004 at 04:02:34PM -0500, Steve Snyder wrote: >> >>>There seems to be a controversy about the use of the CONFIG_HIGHMEM4G >>>kernel configuration. After reading many posts on the subject, I still >>>don't know which setting is best for me.
No idea what the performance hit is of highmem these days - it seems insignificant compared to 2.4 so I've had it enabled for 1Gb ram.
> There's also the option of moving the mapping only slightly, so that all > of the 1G fits in low memory. That's the best option for 1G desktop > machines, imho. Changing PAGE_OFFSET from 0xc0000000 to 0xb0000000 would > probably be enough. > > Then you can have your cake and eat it too.
Something like this attached patch? Seems to work nicely. Thanks!
Cheers, Con Index: linux-2.6.8-rc2-mm2/arch/i386/kernel/vmlinux.lds.S =================================================================== --- linux-2.6.8-rc2-mm2.orig/arch/i386/kernel/vmlinux.lds.S 2004-05-23 12:54:46.000000000 +1000 +++ linux-2.6.8-rc2-mm2/arch/i386/kernel/vmlinux.lds.S 2004-08-04 00:20:02.219462913 +1000 @@ -11,7 +11,7 @@ jiffies = jiffies_64; SECTIONS { - . = 0xC0000000 + 0x100000; + . = 0xB0000000 + 0x100000; /* read-only */ _text = .; /* Text and read-only data */ .text : { Index: linux-2.6.8-rc2-mm2/include/asm-i386/page.h =================================================================== --- linux-2.6.8-rc2-mm2.orig/include/asm-i386/page.h 2004-08-03 01:29:28.000000000 +1000 +++ linux-2.6.8-rc2-mm2/include/asm-i386/page.h 2004-08-03 23:58:16.000000000 +1000 @@ -123,9 +123,9 @@ #endif /* __ASSEMBLY__ */ #ifdef __ASSEMBLY__ -#define __PAGE_OFFSET (0xC0000000) +#define __PAGE_OFFSET (0xB0000000) #else -#define __PAGE_OFFSET (0xC0000000UL) +#define __PAGE_OFFSET (0xB0000000UL) #endif [unhandled content-type:application/pgp-signature] | |