Messages in this thread |  | | | Date | Tue, 6 Mar 2012 10:14:11 +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:
> * Peter Zijlstra <peterz@infradead.org> [2012-02-20 20:07:46]: > > > On Mon, 2012-02-20 at 19:14 +0100, Mike Galbraith wrote:
> > > Enabling SD_BALANCE_WAKE used to be decidedly too > > > expensive to consider. Maybe that has changed, but I doubt > > > it. > > > > Right, I through I remembered somet such, you could see it > > on wakeup heavy things like pipe-bench and that java msg > > passing thing, right? > > I did some experiments with volanomark and it does turn out to > be sensitive to SD_BALANCE_WAKE, while the other wake-heavy > benchmark that I am dealing with (Trade) benefits from it.
Does volanomark still do yield(), thereby invoking a random shuffle of thread scheduling and pretty much voluntarily ejecting itself from most scheduler performance considerations?
If it uses a real locking primitive such as futexes then its performance matters more.
Thanks,
Ingo
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