On Wed, 2013-04-17 at 17:53 -0400, Len Brown wrote: > On 04/12/2013 12:48 PM, Mike Galbraith wrote: > > On Fri, 2013-04-12 at 18:23 +0200, Borislav Petkov wrote: > >> On Fri, Apr 12, 2013 at 04:46:50PM +0800, Alex Shi wrote: > >>> Thanks a lot for comments, Len! > >> > >> AFAICT, you kinda forgot to answer his most important question: > >> > >>> These numbers suggest that this patch series simultaneously > >>> has a negative impact on performance and energy required > >>> to retire the workload. Why do it? > > > > Hm. When I tested AIM7 compute on a NUMA box, there was a marked > > throughput increase at the low to moderate load end of the test spectrum > > IIRC. Fully repeatable. There were also other benefits unrelated to > > power, ie mitigation of the evil face of select_idle_sibling(). I > > rather liked what I saw during ~big box test-drive. > > > > (just saying there are other aspects besides joules in there) > > Mike, > > Can you re-run your AIM7 measurement with turbo-mode and HT-mode disabled, > and then independently re-enable them? > > If you still see the performance benefit, then that proves > that the scheduler hacks are not about tricking into > turbo mode, but something else.
I did that today, neither turbo nor HT affected the performance gain. I used the same box and patch set as tested before (v4), but plugged into linus HEAD. "powersaving" AIM7 numbers are ~identical to those I posted before, "performance" is lower at the low end of AIM7 test spectrum, but as before, delta goes away once the load becomes hefty. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
