From: peterz@infradead.org
To: luca abeni <luca.abeni@santannapisa.it>
Cc: Juri Lelli <juri.lelli@redhat.com>,
mingo@redhat.com, rostedt@goodmis.org, tglx@linutronix.de,
linux-kernel@vger.kernel.org, tommaso.cucinotta@santannapisa.it,
alessio.balsini@gmail.com, bristot@redhat.com,
dietmar.eggemann@arm.com, linux-rt-users@vger.kernel.org,
mtosatti@redhat.com, williams@redhat.com,
valentin.schneider@arm.com
Subject: Re: [RFC PATCH v2 6/6] sched/fair: Implement starvation monitor
Date: Fri, 7 Aug 2020 16:11:18 +0200 [thread overview]
Message-ID: <20200807141118.GK2674@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200807154941.2bb11408@nowhere>
On Fri, Aug 07, 2020 at 03:49:41PM +0200, luca abeni wrote:
> Hi Peter,
>
> peterz@infradead.org wrote:
> > One thing I considerd was scheduling this as a least-laxity entity --
> > such that it runs late, not early
>
> Are you thinking about scheduling both RT and non-RT tasks through
> deadline servers? If yes,
Maybe, I initially considered this for mixed criticality, where the
'soft' class would run EDF and the 'hard' class would run LLF (or the
other way around, I can't quite remember how I figured it).
If you restrict the hard class to single CPU assignment (IOW the UP
case) and ensure that u_llf + U_gedf/N < 1, it should just work out.
But I shelved all that after I heard about that other balancer idea
Danial was suppose to be working on ;-)))
> then I think that using something like
> laxity-based scheduling for the SCHED_OTHER server can be a good idea
> (but then we need to understand how to combine deadline-based
> scheduling with laxity-based scheduling, etc...)
/me consults notes, EDZL is I think the closest thing there.
> Or are you thinking about keeping the SCHED_OTHER server throttled
> until its laxity is 0 (or until its laxity is lower than some small
> value)? In this second case, the approach would work even if RT tasks
> are not scheduled through a server (but I do not know which kind of
> performance guarantee we could provide).
That would certainly be sufficient for OTHER servers I think.
next prev parent reply other threads:[~2020-08-07 14:11 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-07 9:50 [RFC PATCH v2 0/6] SCHED_DEADLINE server infrastructure Juri Lelli
2020-08-07 9:50 ` [RFC PATCH v2 1/6] sched: Unify runtime accounting across classes Juri Lelli
2020-08-07 9:50 ` [RFC PATCH v2 2/6] sched/deadline: Collect sched_dl_entity initialization Juri Lelli
2020-08-07 9:50 ` [RFC PATCH v2 3/6] sched/deadline: Move bandwidth accounting into {en,de}queue_dl_entity Juri Lelli
2020-08-07 9:50 ` [RFC PATCH v2 4/6] sched/deadline: Introduce deadline servers Juri Lelli
2020-10-06 7:56 ` luca abeni
2020-10-06 9:35 ` Juri Lelli
2020-10-06 9:51 ` luca abeni
2020-08-07 9:50 ` [RFC PATCH v2 5/6] sched/fair: Add trivial fair server Juri Lelli
2020-08-07 9:56 ` [RFC PATCH v2 6/6] sched/fair: Implement starvation monitor Juri Lelli
2020-08-07 10:46 ` peterz
2020-08-07 11:30 ` Daniel Bristot de Oliveira
2020-08-07 12:50 ` Juri Lelli
2020-08-07 13:49 ` luca abeni
2020-08-07 14:11 ` peterz [this message]
2020-08-07 16:48 ` Daniel Bristot de Oliveira
2020-08-07 13:28 ` luca abeni
2020-08-07 13:43 ` Juri Lelli
2020-08-07 13:55 ` luca abeni
2020-08-07 14:11 ` Juri Lelli
2020-08-07 14:13 ` peterz
2020-08-07 15:06 ` Juri Lelli
2020-08-07 13:16 ` [RFC PATCH v2 0/6] SCHED_DEADLINE server infrastructure luca abeni
2020-08-07 13:30 ` Juri Lelli
2020-08-07 13:41 ` luca abeni
2020-08-07 14:04 ` Juri Lelli
2020-08-07 14:14 ` peterz
2020-09-08 22:22 ` Pavel Machek
2020-09-09 5:51 ` Juri Lelli
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