Re: [patch] sched-2.5.59-A2

[William Lee Irwin III <wli@holomorphy.com>]

On Fri, Jan 17, 2003 at 04:11:59PM +0100, Ingo Molnar wrote:
> agreed, i've attached the -B0 patch that does this. The balancing rates
> are 1 msec, 2 msec, 200 and 400 msec (idle-local, idle-global, busy-local,
> busy-global).

I suspect some of these results may be off on NUMA-Q (or any PAE box)
if CONFIG_MTRR was enabled. Michael, Martin, please doublecheck
/proc/mtrr and whether CONFIG_MTRR=y. If you didn't enable it, or if
you compile times aren't on the order of 5-10 minutes, you're unaffected.

The severity of the MTRR regression in 2.5.59 is apparent from:
$ cat /proc/mtrr
reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1
reg01: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
$ time make -j bzImage > /dev/null
make -j bzImage > /dev/null  8338.52s user 245.73s system 1268% cpu 11:16.56 total

Fixing it up by hand (after dealing with various bits of pain) to:
$ cat /proc/mtrr
reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1
reg01: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg02: base=0x100000000 (4096MB), size=4096MB: write-back, count=1
reg03: base=0x200000000 (8192MB), size=4096MB: write-back, count=1
reg04: base=0x300000000 (12288MB), size=4096MB: write-back, count=1
reg05: base=0x400000000 (16384MB), size=16384MB: write-back, count=1
reg06: base=0x800000000 (32768MB), size=16384MB: write-back, count=1
reg07: base=0xc00000000 (49152MB), size=16384MB: write-back, count=1

make -j bzImage > /dev/null  361.72s user 546.28s system 2208% cpu 41.109 total
make -j bzImage > /dev/null  364.00s user 575.73s system 2005% cpu 46.858 total
make -j bzImage > /dev/null  366.77s user 568.44s system 2239% cpu 41.765 total

I'll do some bisection search to figure out which patch broke the world.

-- wli