Re: [Lse-tech] [PATCH 1/2] node affine NUMA scheduler

["Martin J. Bligh" <mbligh@aracnet.com>]

> would you please check the boot messages for the NUMA scheduler before
> doing the run. Martin sent me an example where he has:
> 
> CPU pools : 1
> pool 0 :0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
> node level 0 : 10
> pool_delay matrix:
>  129 
> 
> which is clearly wrong. In that case we need to fix the cpu-pools setup
> first.

OK, well I hacked this for now:

sched.c somewhere:
- lnode_number[i] = pnode_to_lnode[SAPICID_TO_PNODE(cpu_physical_id(i))];
+ lnode_number[i] = i/4;

Which makes the pools work properly. I think you should just use
the cpu_to_node macro here, but the hack will allow us to do some
testing.

Results, averaged over 5 kernel compiles:

Before:
Elapsed: 20.82s User: 191.262s System: 59.782s CPU: 1206.4%
After:
Elapsed: 21.918s User: 190.224s System: 59.166s CPU: 1137.4%

So you actually take a little less horsepower to do the work, but 
don't utilize the CPUs quite as well, so elapsed time is higher.
I seem to recall getting better results from Mike's quick hack
though ... that was a long time back. What were the balancing 
issues you mentioned?

M.