On 29 May 2014 15:55, Peter Zijlstra <[email protected]> wrote: > On Fri, May 23, 2014 at 05:53:05PM +0200, Vincent Guittot wrote: >> The scheduler tries to compute how many tasks a group of CPUs can handle by >> assuming that a task's load is SCHED_LOAD_SCALE and a CPU capacity is >> SCHED_POWER_SCALE. >> We can now have a better idea of the utilization of a group fo CPUs thanks to >> group_actitvity and deduct how many capacity is still available. >> >> Signed-off-by: Vincent Guittot <[email protected]> >> --- > > Right, so as Preeti already mentioned, this wrecks SMT. It also seems to > loose the aggressive spread, where we want to run 1 task on each 'core' > before we start 'balancing'. > > So I think we should be able to fix this by setting PREFER_SIBLING on > the SMT domain, that way we'll get single tasks running on each SMT > domain before filling them up until capacity. > > Now, its been a while since I looked at PREFER_SIBLING, and I've not yet > looked at what your patch does to it, but it seems to me that that is > the first direction we should look for an answer to this.
OK, i'm going to look more deeply in PREFER_SIBLING too -- 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/
