Re: lost memory on a 4GB amd64

[Andrew Walrond <andrew@walrond.org>]

On Friday 24 Sep 2004 12:42, you wrote:
>
> NUMA was enabled all the time (at least most of the time). I don't know if
> I ever ran it without NUMA. I'll certainly try that.
>
> Unfortunately, I won't be able to do any reboots during the next one or
> two weeks since the machine has gone into stable operation tonight. (with
> some loss of memory for now)
>
> if it is of some interest, that's what dmesg tells about NUMA:
>
>      BIOS-provided physical RAM map:
>       BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
>       BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
>       BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
>       BIOS-e820: 0000000000100000 - 00000000bfff0000 (usable)
>       BIOS-e820: 00000000bfff0000 - 00000000bffff000 (ACPI data)
>       BIOS-e820: 00000000bffff000 - 00000000c0000000 (ACPI NVS)
>       BIOS-e820: 00000000ff780000 - 0000000100000000 (reserved)
>       BIOS-e820: 0000000100000000 - 0000000140000000 (usable)
>      Scanning NUMA topology in Northbridge 24
>      Number of nodes 2 (10010)
>      Node 0 MemBase 0000000000000000 Limit 000000013fffffff
>      Skipping disabled node 1
>      Using node hash shift of 24
>      Bootmem setup node 0 0000000000000000-000000013fffffff
>      No mptable found.
>      On node 0 totalpages: 1310719
>        DMA zone: 4096 pages, LIFO batch:1
>        Normal zone: 1306623 pages, LIFO batch:16
>        HighMem zone: 0 pages, LIFO batch:1
>
> So actually it looks like the kernel well notices that only one processor
> has access to the memory here.
>

Intriguing. If it works with NUMA disabled, it would strongly indicate a bug 
in the NUMA kernel code.

Definately worth a try as soon as you can afford to take the machine down for 
a few minutes.

Andrew