On Fri, 2014-04-25 at 04:45 +0200, Mike Galbraith wrote: > On Thu, 2014-04-24 at 18:52 +0200, Peter Zijlstra wrote: > > On Thu, Apr 24, 2014 at 09:43:09AM -0700, Jason Low wrote: > > > If the below patch is what you were referring to, I believe this > > > can help too. This was also something that I was testing out before > > > we went with those patches which compares avg_idle with idle balance > > > cost. I recall seeing somewhere around a +7% performance improvement > > > in at least least 1 of the AIM7 workloads. I can do some more testing > > > with this. > > > > Yes, exactly that. > > > > I can't remember the details, but I suspect we feared the less agressive > > idle balance due to that patch (it will only pull a single task, instead > > of multiple) would cause more idle_balance invocations and thereby > > decrease throughput. > > > > So I suppose something with _many_ bursty threads which leads to severe > > inequalities would be the workload to trigger that. > > > > Not sure we've ever seen that.. maybe Mike remembers, he seems to have a > > head for such details. > > I don't recall ever seeing such.
Hmmm, could commit: 1b9508f6831e (sched: Rate-limit newidle) be related to what Peter's referring to? The patch mentioned that the rate-limit benefited "sysbench oltp". -- 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/
