Messages in this thread | | | Date | Thu, 11 Feb 2016 13:22:54 +0100 | From | luca abeni <> | Subject | Re: [PATCH 1/2] sched/deadline: add per rq tracking of admitted bandwidth |
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Hi Juri,
On Thu, 11 Feb 2016 12:12:57 +0000 Juri Lelli <juri.lelli@arm.com> wrote: [...] > I think we still have (at least) two problems: > > - select_task_rq_dl, if we select a different target > - select_task_rq might make use of select_fallback_rq, if > cpus_allowed changed after the task went to sleep > > Second case is what creates the problem here, as we don't update > task_rq(p) and fallback_cpu ac_bw. I was thinking we might do so, > maybe adding fallback_cpu in task_struct, from migrate_task_rq_dl() > (it has to be added yes), but I fear that we should hold both rq > locks :/. > > Luca, did you already face this problem (if I got it right) and > thought of a way to fix it? I'll go back and stare a bit more at > those paths. In my patch I took care of the first case (modifying select_task_rq_dl() to move the utilization from the "old rq" to the "new rq"), but I never managed to trigger select_fallback_rq() in my tests, so I overlooked that case.
Luca
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