Messages in this thread |  | | Subject | Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes | From | Dietmar Eggemann <> | Date | Fri, 14 Oct 2016 14:10:07 +0100 |
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On 14/10/16 09:24, Vincent Guittot wrote: > On 13 October 2016 at 23:34, Vincent Guittot <vincent.guittot@linaro.org> wrote: >> On 13 October 2016 at 20:49, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote: >>> On 13/10/16 17:48, Vincent Guittot wrote: >>>> On 13 October 2016 at 17:52, Joseph Salisbury >>>> <joseph.salisbury@canonical.com> wrote: >>>>> On 10/13/2016 06:58 AM, Vincent Guittot wrote: >>>>>> Hi, >>>>>> >>>>>> On 12 October 2016 at 18:21, Joseph Salisbury >>>>>> <joseph.salisbury@canonical.com> wrote: >>>>>>> On 10/12/2016 08:20 AM, Vincent Guittot wrote: >>>>>>>> On 8 October 2016 at 13:49, Mike Galbraith <efault@gmx.de> wrote: >>>>>>>>> On Sat, 2016-10-08 at 13:37 +0200, Vincent Guittot wrote: >>>>>>>>>> On 8 October 2016 at 10:39, Ingo Molnar <mingo@kernel.org> wrote: >>>>>>>>>>> * Peter Zijlstra <peterz@infradead.org> wrote: >>>>>>>>>>> >>>>>>>>>>>> On Fri, Oct 07, 2016 at 03:38:23PM -0400, Joseph Salisbury wrote:
[...]
>>> When I create a tg_root/tg_x/tg_y_1 and a tg_root/tg_x/tg_y_2 group, the tg_x->load_avg >>> becomes > 6*1024 before any tasks ran in it. >> >> This is normal as se->avg.load_avg is initialized to >> scale_load_down(se->load.weight) and this se->avg.load_avg will be >> added to tg_x[cpu]->cfs_rq->avg.load_avg when attached to the cfs_rq
Yeah, you right, even when I've created 50 second level groups, tg_x->load_avg is ~6800.
Could it have something to do with the fact that .se->load.weight = 2 for all these task groups? on a 64bit system?
In case we call __update_load_avg(..., se->on_rq * scale_load_down(se->load.weight), ...) we pass a weight argument of 0 for these se's.
Does not happen with:
- if (shares < MIN_SHARES) - shares = MIN_SHARES; + if (shares < scale_load(MIN_SHARES)) + shares = scale_load(MIN_SHARES);
in calc_cfs_shares().
[...]
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