Hi, Mike :) On 06/30/2014 04:06 PM, Mike Galbraith wrote: > On Mon, 2014-06-30 at 15:36 +0800, Michael wang wrote: >> On 06/18/2014 12:50 PM, Michael wang wrote: >>> By testing we found that after put benchmark (dbench) in to deep cpu-group, >>> tasks (dbench routines) start to gathered on one CPU, which lead to that the >>> benchmark could only get around 100% CPU whatever how big it's task-group's >>> share is, here is the link of the way to reproduce the issue: >> >> Hi, Peter >> >> We thought that involved too much factors will make things too >> complicated, we are trying to start over and get rid of the concepts of >> 'deep-group' and 'GENTLE_FAIR_SLEEPERS' in the idea, wish this could >> make things more easier... > > While you're getting rid of the concept of 'GENTLE_FAIR_SLEEPERS', don't > forget to also get rid of the concept of 'over-scheduling' :)
I'm new to this word... could you give more details on that? > > That gentle thing isn't perfect (is the enemy of good), but preemption > model being based upon sleep, while nice and simple, has the unfortunate > weakness that as contention increases, so does the quantity of sleep in > the system. Would be nice to come up with an alternative preemption > model as dirt simple as this one, but lacking the inherent weakness. The preemtion based on vruntime sounds fair enough, but vruntime-bonus for wakee do need few more thinking... although I don't want to count the gentle-stuff in any more, but disable it do help dbench a lot... Regards, Michael Wang > > -Mike > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
