Re: Database regression due to scheduler changes ?

Martin J. Bligh
2005-11-08T01:34:41Z

>> I would also take a look at removing SD_WAKE_IDLE from the flags.
>> This flag should make balancing more aggressive, but it can have
>> problems when applied to a NUMA domain due to too much task
>> movement.
>
> I was wondering how ppc64 ended up with different parameters in the NODE
> definitions (added SD_BALANCE_NEWIDLE and SD_WAKE_IDLE) and it looks
> like it was Andrew :)
>
> http://lkml.org/lkml/2004/11/2/205
>
> It looks like balancing was not agressive enough on his workload too.
> Im a bit uneasy with only ppc64 having the two flags though.
>
> Im also considering adding balance on fork for ppc64, it seems like a
> lot of people like to run stream like benchmarks and Im getting tired of
> telling them to lock their threads down to cpus.

Please don't screw up everything else just for stream. It's a silly
frigging benchmark. There's very little real-world stuff that really
needs balance on fork, as opposed to balance on clone, and it'll slow
down everything else.

M.