J.A. Magallon wrote:
Hi...
I have some Quad-Opteron boxes with 4Gb memory and two of them are
running two different Linux distros.
Box one sees 4Gb of memory, but box two just sees 3.
Their mtrr setups are different:
Why ? Is it a bios setup problem ? A kernel problem ?
grep HIGHMEN in configs for both kernels does not give anything, so
I still understand less this thing...
It would depend on how the BIOS programmed the memory controllers. For
32-bit (and lots of device) compatibility, a memory hole is required
below 4 GB. Not all memory controllers can remap memory in the 3-4 GB
range above the 4 GB memory; I'm not sure if that varies with the
different Opteron processors.
Also, if you run a 32-bit distribution, you need to have HIGHMEM_64G
enabled in the kernel.
-hpa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
