On 31 July 2014 21:16, Yuyang Du <yuyang...@intel.com> wrote: > Hi Vincent, > > On Thu, Jul 31, 2014 at 11:56:13AM +0200, Vincent Guittot wrote: >> >> load_sum is now the average runnable time before being weighted > > So when weight changes, load_avg will completely use new weight. I have > some cents: > > 1) Task does not change weight much, so it is practically ok > > 2) Group entity does change weight much, and very likely back and forth, > so I really think keeping the intact history will make everything > more predictable/stable, prevent thrashing, etc. > > 3) If you do the same for cfs_rq->load.weight, then we simply abandoned > blocked entities, and all states won't compute. So we then need to > maintain blocked load average again, and we just can't do cfs_rq load > average as a whole anymore, but must update at the granularity of an > entity... > > Anyway, it does not seem to me you really need to change load_sum, no? So > could you please not change it? > >> The sum of usage_sum of the tasks that are on a rq, is used to detect >> the overload of a rq. > > I think you only need usage_sum for task and rq, but not cfs_rq. Others > are ok.
yes, only usage_sum is useful for my rework of cpu_power > >> Does something like the patch below to be applied of top of your patchset, >> seem >> reasonable add-on? >> > > If you only add running statistics, I am all good, and indeed reasonable if > you can make good use of it. I am not at all against adding anything or > adding running average or unweighted anything... ok. Thanks Vincent > > Thanks, > Yuyang -- 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/
