Re: 512MB/1GB RAM

Re: 512MB/1GB RAM

[Peter Suetterlin]

  Hello Peng,

I found your mail posting via google, because I do have the same
problems as you and was looking for a solution:

I have an Asus M3N that is supposed to support 1GB of memory.  I
bought it with 512MB, and everything worked fine,  Then I bought a
memory upgrade of another 512MB, and as soon as I plug it in, I get
two problems:

- without anything else, i.e., using the full 1GB of memory, the
  system is unusably slow (takes some 5-10 minutes just to boot).
  The main problem seems to be the hard disk, things that do not need
  the disk seem to work OK (I didn't try much - the system really is
  unusable...)

- I can restrict the memory usage with, e.g., mem=992M.  Then
  immediately the speed is back - but the pcmcia card slot no longer
  works. Same is true for the sound.

I'm (trying to) post this to the LKML - not sure if it's possible, as
I'm not subscribed.  But if soeone needs more info I'm willing to test
stuff out.
Best,

  Pit

-- 
Dr. Peter "Pit" Suetterlin                 http://www.astro.uu.nl/~suetter
Sterrenkundig Instituut Utrecht
Tel.: +31 (0)30 253 5225                   P.Suetterlin@astro.uu.nl

Re: 512MB/1GB RAM

[Peng Li]

This patch works for me.  Thanks.

I used to patch the copy_e820_map() by filling some holes in the
BIOS memory region as E820_RESERVED, i.e.

add_memory_region(0x3ff7a000ULL,0x3ff80000ULL-0x3ff7a000ULL,E820_RESERVED);

Otherwise some of my PCI devices will be mapped to somewhere between
0x3ff7a000 and 0x3ff80000, which doesn't seem to work.  Is it a bug of
the BIOS?

Linux version 2.6.0-test9 (root@think) (gcc version 3.2.3 20030422 (Gentoo Linux 1.4 3.2.3-r2, propolice)) #11 Wed Nov 12 15:42:56 EST 2003
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009f000 (usable)
 BIOS-e820: 000000000009f000 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000dc000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 000000003ff60000 (usable)
 BIOS-e820: 000000003ff60000 - 000000003ff78000 (ACPI data)
 BIOS-e820: 000000003ff78000 - 000000003ff7a000 (ACPI NVS)
 BIOS-e820: 000000003ff80000 - 0000000040000000 (reserved)
 BIOS-e820: 00000000ff800000 - 0000000100000000 (reserved)

-- Peng

On Mon, Nov 10, 2003 at 09:08:34AM -0800, Linus Torvalds wrote:
> Try this patch and tell me if it makes a difference.
> 
> --- 1.102/arch/i386/kernel/setup.c	Tue Oct 21 22:10:28 2003
> +++ edited/arch/i386/kernel/setup.c	Mon Nov 10 08:23:46 2003
> @@ -87,7 +87,7 @@
>  unsigned int mca_pentium_flag;
>  
>  /* For PCI or other memory-mapped resources */
> -unsigned long pci_mem_start = 0x10000000;
> +unsigned long pci_mem_start = 0x40000000;
>  
>  /* user-defined highmem size */
>  static unsigned int highmem_pages = -1;
>