From: Valentin Schneider <valentin.schneider@arm.com>
To: Juri Lelli <juri.lelli@redhat.com>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
peterz@infradead.org, vincent.guittot@linaro.org,
tglx@linutronix.de, qais.yousef@arm.com,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH v2 0/4] sched/fair: Active balancer RT/DL preemption fix
Date: Tue, 1 Oct 2019 15:15:28 +0100 [thread overview]
Message-ID: <c4f7940e-8a8a-378e-ca02-034e3b7348ef@arm.com> (raw)
In-Reply-To: <20191001133115.GC6481@localhost.localdomain>
Hi Juri,
On 01/10/2019 14:31, Juri Lelli wrote:
> Hi Valentin,
>
> On 01/10/19 11:29, Valentin Schneider wrote:
>> (expanded the Cc list)
>> RT/DL folks, any thought on the thing?
>
> Even if I like your idea and it looks theoretically the right thing to
> do, I'm not sure we want it in practice if it adds complexity to CFS.
>
> I personally never noticed this kind of interference from CFS, but, at
> the same time, for RT we usually like more to be safe than sorry.
> However, since this doesn't seem to be bullet-proof (as you also say), I
> guess it all boils down again to complexity vs. practical benefits.
>
Thanks for having a look.
IMO worst part is the local detach_one_task() thing, I added that after v1
following Qais' comments but perhaps it doesn't gain us much.
I'll try to cook something up with rt-app and see if I can get sensible
numbers.
> Best,
>
> Juri
>
prev parent reply other threads:[~2019-10-01 14:15 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-15 14:51 [PATCH v2 0/4] sched/fair: Active balancer RT/DL preemption fix Valentin Schneider
2019-08-15 14:51 ` [PATCH v2 1/4] sched/fair: Make need_active_balance() return bools Valentin Schneider
2019-08-15 14:51 ` [PATCH v2 2/4] sched/fair: Move active balance logic to its own function Valentin Schneider
2019-10-01 11:36 ` Srikar Dronamraju
2019-10-01 11:48 ` Valentin Schneider
2019-08-15 14:51 ` [PATCH v2 3/4] sched/fair: Check for CFS tasks before detach_one_task() Valentin Schneider
2019-08-15 14:51 ` [PATCH v2 4/4] sched/fair: Prevent active LB from preempting higher sched classes Valentin Schneider
2019-08-27 12:28 ` Vincent Guittot
2019-08-28 9:46 ` Valentin Schneider
2019-08-29 14:19 ` Vincent Guittot
2019-08-30 15:44 ` Valentin Schneider
2019-10-01 10:29 ` [PATCH v2 0/4] sched/fair: Active balancer RT/DL preemption fix Valentin Schneider
2019-10-01 13:31 ` Juri Lelli
2019-10-01 14:15 ` Valentin Schneider [this message]
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