RE: Delete scheduler SD_WAKE_AFFINE and SD_WAKE_BALANCE flags

Chen, Kenneth W
2005-07-29T17:30:12Z

Ingo Molnar wrote on Friday, July 29, 2005 4:26 AM
> * Chen, Kenneth W <kenneth.w.chen@intel.com> wrote:
> > To demonstrate the problem, we turned off these two flags in the cpu
> > sd domain and measured a stunning 2.15% performance gain! And
> > deleting all the code in the try_to_wake_up() pertain to load
> > balancing gives us another 0.2% gain.
>
> another thing: do you have a HT-capable ia64 CPU, and do you have
> CONFIG_SCHED_SMT turned on? If yes then could you try to turn off
> SD_WAKE_IDLE too, i found it to bring further performance improvements
> in certain workloads.

The scheduler experiments done so far are on non-SMT CPU (Madison processor).
We have another db setup with multi-thread capable ia64 cpu (montecito, and to
be precise, it is SOEMT capable). We are just about to do scheduler experiments
on that setup.