Re: lost memory on a 4GB amd64

[Sergei Haller]

I just discovered the linux-smp list and decided to summarize the topic 
and take the opportunity to cross-post to there.

an archive of the discussion can be found e.g. here:
http://marc.theaimsgroup.com/?t=109525952600004&r=1&w=4


The machine at hand is the Tyan Tiger K8W with two Opterons 246
(http://www.tyan.com/products/html/tigerk8w.html) and 4GB of memory

we are using vanilla 2.6.8.1 kernel.

 * if the memory is set up in the ordinary way in the BIOS, then
   approximately 512MB are lost (PCI/AGM adressing and stuff), but
   everything is stable
 * if the memory is set up in the BIOS to be in two chunks (e.g. 3GB at 
   the address range 0-3GB and 1GB at 4-5GB address range), then
    - memtest86 tells everything is fine.
    - if we run a non-SMP kernel, everything is stable
    - if we run an SMP kernel, it crashes as soon as approx. 1GB of memory
      is allocated and set to 0 (see the test case C-program in my
      previous mail)

Is there anything we can do? Any logs I can provide? Something to try out?

Thanks,
        Sergei
-- 
--------------------------------------------------------------------  -?)
         eMail:       Sergei.Haller@xxxxxxxxxxxxxxxxxxx               /\\
-------------------------------------------------------------------- _\_V
Be careful of reading health books, you might die of a misprint.
                -- Mark Twain
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/