Re: Terrible IO performance when using 4GB of RAM on a 32 bit machine

From: Peter Rabbitson
Date: Thu Jun 21 2007 - 19:02:27 EST


H. Peter Anvin wrote:
Peter Rabbitson wrote:
I have captured dmesg output without mem[5], with mem=3900M[6] and
mem=2048M[7].


What does /proc/mtrr look like in the two cases?


Identical for mem=3900 and without it.

reg00: base=0x00000000 ( 0MB), size=2048MB: write-back, count=1

reg01: base=0x80000000 (2048MB), size=1024MB: write-back, count=1

reg02: base=0xc0000000 (3072MB), size= 512MB: write-back, count=1

reg03: base=0xe0000000 (3584MB), size= 256MB: write-back, count=1

reg04: base=0xf0000000 (3840MB), size= 128MB: write-back, count=1

reg05: base=0xf8000000 (3968MB), size= 32MB: write-back, count=1


Peter
-
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/