From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>,
Ingo Molnar <mingo@redhat.com>, Christoph Lameter <cl@linux.com>,
linux-rt-users <linux-rt-users@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sched/rt: RT_RUNTIME_GREED sched feature
Date: Tue, 8 Nov 2016 12:17:10 -0500 [thread overview]
Message-ID: <20161108121710.3e7eb664@gandalf.local.home> (raw)
In-Reply-To: <20161108165133.GI3117@twins.programming.kicks-ass.net>
On Tue, 8 Nov 2016 17:51:33 +0100
Peter Zijlstra <peterz@infradead.org> wrote:
> You really should already know this.
I know what we want to do, but there's some momentous problems that
need to be solved first. Until then, we may be forced to continue with
hacks.
>
> As stands the current rt cgroup code (and all this throttling code) is a
> giant mess (as in, its not actually correct from a RT pov). We should
> not make it worse by adding random hacks to it.
>
> The right way to to about doing this is by replacing it with something
> better; like the proposed DL server for FIFO tasks -- which is entirely
> non-trivial as well, see existing discussion on that.
Right. The biggest issue that I see is how to assign affinities to
FIFO tasks and use a DL server to keep them from starving other tasks?
>
> I'm not entirely sure what this patch was supposed to fix, but it could
> be running CFS tasks with higher priority than RT for a window, instead
I'm a bit confused with the above sentence. Do you mean that this patch
causes CFS tasks to run for a period with a higher priority than RT?
Well, currently we have the both CFS tasks and the "idle" task run
higher than RT, but this patch changes that to be just CFS tasks.
> of throttling RT tasks. This seems fairly ill specified, but something
> like that could easily done with an explicit or slack time DL server for
> CFS tasks.
If we can have a DL scheduler that can handle arbitrary affinities,
then all could be solved with that.
-- Steve
next prev parent reply other threads:[~2016-11-08 17:17 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-07 8:17 [PATCH] sched/rt: RT_RUNTIME_GREED sched feature Daniel Bristot de Oliveira
2016-11-07 10:31 ` Tommaso Cucinotta
2016-11-07 13:51 ` Daniel Bristot de Oliveira
2016-11-07 18:03 ` Tommaso Cucinotta
2016-11-07 18:06 ` Luca Abeni
2016-11-08 7:55 ` luca abeni
2016-11-08 10:30 ` Juri Lelli
2016-11-07 16:55 ` Christoph Lameter
2016-11-07 18:32 ` Steven Rostedt
2016-11-07 18:49 ` Daniel Bristot de Oliveira
2016-11-07 19:16 ` Steven Rostedt
2016-11-07 19:30 ` Christoph Lameter
2016-11-07 19:47 ` Steven Rostedt
2016-11-07 19:54 ` Christoph Lameter
2016-11-07 20:00 ` Steven Rostedt
2016-11-07 20:06 ` Daniel Bristot de Oliveira
2016-11-07 20:16 ` Steven Rostedt
2016-11-07 20:33 ` Daniel Bristot de Oliveira
2016-11-07 20:44 ` Steven Rostedt
2016-11-08 9:22 ` [PATCH] sched/rt: Change default setup for RT THROTTLING Daniel Bristot de Oliveira
2016-11-08 23:42 ` [PATCH] sched/rt: RT_RUNTIME_GREED sched feature Christoph Lameter
2016-11-07 18:22 ` Clark Williams
2016-11-07 18:30 ` Steven Rostedt
2016-11-07 18:38 ` Daniel Bristot de Oliveira
2016-11-07 18:39 ` Clark Williams
2016-11-08 11:59 ` Peter Zijlstra
2016-11-08 14:07 ` Steven Rostedt
2016-11-08 16:51 ` Peter Zijlstra
2016-11-08 17:17 ` Steven Rostedt [this message]
2016-11-08 18:05 ` Peter Zijlstra
2016-11-08 19:29 ` Daniel Bristot de Oliveira
2016-11-08 19:50 ` Peter Zijlstra
2016-11-09 13:33 ` Daniel Bristot de Oliveira
[not found] ` <CAA7rmPF0nQb9721MQWurRCy7E3X46hAy2qV=joK=z5U-t70NOg@mail.gmail.com>
2016-11-11 18:46 ` Christoph Lameter
2016-11-11 22:53 ` Peter Zijlstra
2016-11-13 18:53 ` Christoph Lameter
2016-11-14 9:20 ` Peter Zijlstra
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