Messages in this thread | | | Date | Wed, 27 Jan 2016 14:36:51 +0100 | From | Luca Abeni <> | Subject | Re: [RFC 4/8] Improve the tracking of active utilisation |
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Hi Peter,
On Tue, 19 Jan 2016 14:47:39 +0100 Peter Zijlstra <peterz@infradead.org> wrote: > On Tue, Jan 19, 2016 at 01:20:13PM +0100, Luca Abeni wrote: > > Hi Peter, > > > > On 01/14/2016 08:43 PM, Peter Zijlstra wrote: > > >On Thu, Jan 14, 2016 at 04:24:49PM +0100, Luca Abeni wrote: > > >>This patch implements a more theoretically sound algorithm for > > >>thracking the active utilisation: instead of decreasing it when a > > >>task blocks, use a timer (the "inactive timer", named after the > > >>"Inactive" task state of the GRUB algorithm) to decrease the > > >>active utilisaation at the so called "0-lag time". > > > > > >See also the large-ish comment in __setparam_dl(). > > > > > >If we go do proper 0-lag, as GRUB requires, then we might as well > > >use it for that. > > Just to check if I understand correctly: > > I would need to remove "dl_b->total_bw -= p->dl.dl_bw;" from > > task_dead_dl(), and __dl_clear() from "else if (!dl_policy(policy) > > && task_has_dl_policy(p))" in dl_overflow(). Then, arm the > > inactive_timer in these cases, and add the __dl_clear() in the "if > > (!dl_task(p))" in inactive_task_timer()... Right? > > Correct. > > > If this understanding is correct (modulo some details that I'll > > figure out during testing), I'll try this. > > Yes, there's bound to be 'fun' details..
Ok, so I implemented this idea, and I am currently testing it... The first experiments seem to show that there are no problems, but I just tried some simple workload (rt-app, or some other periodic taskset scheduled by SCHED_DEADLINE). Do you have suggestions for more "interesting" (and meaningful) tests/experiments?
Thanks, Luca
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