On Sat, 9 Jul 2005 01:00:54 -0700, Sheo Shanker Prasad wrote: >(1) content of /proc/mtrr : > >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= 128MB: write-back, count=1 >reg03: base=0xc8000000 (3200MB), size= 64MB: write-back, count=1 >reg04: base=0xd0000000 (3328MB), size= 256MB: write-combining, count=2 > >(2) BIOS provided RAM map: > > BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) > BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved) > BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved) > BIOS-e820: 0000000000100000 - 00000000cbff0000 (usable) > BIOS-e820: 00000000cbff0000 - 00000000cbfff000 (ACPI data) > BIOS-e820: 00000000cbfff000 - 00000000cc000000 (ACPI NVS) > BIOS-e820: 00000000ff780000 - 0000000100000000 (reserved)
Your BIOS gives you "usable" memory up to 0xcbff0000-1, but it set up the MTRRs to only cache up to 0xc8010000-1. Thus the memory at 0xc8010000 to 0xcbff0000-1 will be slow as h*ll. This is a BIOS problem. An upgrade (if available) may help. Using mem=3264M should work around the MTRR issue. You've apparently tried that, so whatever's causing your performance variations must be something else. /Mikael - 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/
