Messages in this thread | | | Date | Thu, 23 Feb 2012 12:19:29 +0100 | From | Ingo Molnar <> | Subject | Re: sched: Avoid SMT siblings in select_idle_sibling() if possible |
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* Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> wrote:
> * Mike Galbraith <efault@gmx.de> [2012-02-20 19:14:21]: > > > > I was looking at this code due to vatsa wanting to do SD_BALANCE_WAKE. > > > > I really really need to find time to do systematic mainline testing. > > > > Enabling SD_BALANCE_WAKE used to be decidedly too expensive to consider. > > Maybe that has changed, but I doubt it. (general aside: testing with a > > bloated distro config is a big mistake) > > I am seeing 2.6% _improvement_ in volanomark score by enabling SD_BALANCE_WAKE > at SMT/MC domains. > > Machine : 2 Quad-core Intel X5570 CPU (H/T enabled) > Kernel : tip (HEAD at 6241cc8) > Java : OpenJDK 1.6.0_20 > Volano : 2_9_0 > > Volano benchmark was run 4 times with and w/o SD_BALANCE_WAKE enabled in > SMT/MC domains. > > Average score std. dev > > SD_BALANCE_WAKE disabled 369459.750 4825.046 > SD_BALANCE_WAKE enabled 379070.500 379070.5 > > I am going to try pipe benchmark next. Do you have suggestions > for any other benchmarks I should try to see the effect of > SD_BALANCE_WAKE turned on in SMT/MC domains?
sysbench is one of the best ones punishing bad scheduler balancing mistakes.
Thanks,
Ingo
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