>>>>> "Waiman" == Waiman Long <waiman.long@xxxxxx> writes: Waiman> On 09/04/2013 04:40 PM, John Stoffel wrote: >>>>>>> "Waiman" == Waiman Long<waiman.long@xxxxxx> writes: Waiman> In term of AIM7 performance, this patch has a performance boost of Waiman> about 6-7% on top of Linus' lockref patch on a 8-socket 80-core DL980. >> Waiman> User Range | 10-100 | 200-10000 | 1100-2000 | Waiman> Mean JPM w/o patch | 4,365,114 | 7,211,115 | 6,964,439 | Waiman> Mean JPM with patch | 3,872,850 | 7,655,958 | 7,422,598 | Waiman> % Change | -11.3% | +6.2% | +6.6% | >> >> This -11% impact is worisome to me, because at smaller numbers of >> users, I would still expect the performance to go up. So why the big >> drop? >> >> Also, how is the impact of these changes on smaller 1 socket, 4 core >> systems? Just because it helps a couple of big boxes, doesn't mean it >> won't hurt the more common small case. >> >> John Waiman> I don't believe the patch will make it slower with less Waiman> user. It is more a result of run-to-run variation. The short Waiman> workload typically completed in a very short time. In the Waiman> 10-100 user range, the completion times range from Waiman> 0.02-0.11s. With a higher user count, it needs several seconds Waiman> to run and hence the results are more reliable. Can you then show the variation over multiple runs? I think you have a good justification for larger boxes to make this change, I just worry about smaller systems getting hit and losing performance. John -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
