From: Peter Zijlstra <peterz@infradead.org>
To: Raistlin <raistlin@linux.it>
Cc: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Chris Friesen <cfriesen@nortel.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Darren Hart <darren@dvhart.com>, Henrik Austad <henrik@austad.us>,
Johan Eker <johan.eker@ericsson.com>,
"p.faure" <p.faure@akatech.ch>,
linux-kernel <linux-kernel@vger.kernel.org>,
Claudio Scordino <claudio@evidence.eu.com>,
michael trimarchi <trimarchi@retis.sssup.it>,
Fabio Checconi <fabio@gandalf.sssup.it>,
Tommaso Cucinotta <t.cucinotta@sssup.it>,
Juri Lelli <juri.lelli@gmail.com>,
Nicola Manica <nicola.manica@gmail.com>,
Luca Abeni <luca.abeni@unitn.it>
Subject: Re: [RFC][PATCH 02/11] sched: SCHED_DEADLINE policy implementation.
Date: Tue, 13 Apr 2010 20:22:17 +0200 [thread overview]
Message-ID: <1271182937.4807.1878.camel@twins> (raw)
In-Reply-To: <1267384639.13676.87.camel@Palantir>
On Sun, 2010-02-28 at 20:17 +0100, Raistlin wrote:
> +/*
> + * When a -deadline task is queued back on the runqueue, its runtime and
> + * deadline might need updating.
> + *
> + * The policy here is that we update the deadline of the task only if:
> + * - the current deadline is in the past,
> + * - using the remaining remaining with the current deadline would make
"remaining runtime", I presume?
> + * the task exceed its bandwidth.
> + */
> +static void update_dl_entity(struct sched_dl_entity *dl_se)
> +{
> + struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
> + struct rq *rq = rq_of_dl_rq(dl_rq);
> +
> + /*
> + * The arrival of a new task (or of a new task instance) needs
> + * special treatment. The actual scheduling parameters have to be
> + * "renewed" instead of recalculatetd accordingly to the bandwidth
> + * enforcement rule.
> + */
> + if (dl_se->flags & DL_NEW) {
> + setup_new_dl_entity(dl_se);
> + return;
> + }
> +
> + if (dl_time_before(dl_se->deadline, rq->clock))
> + goto update;
> +
> + if (!dl_check_bandwidth(dl_se, rq->clock)) {
> +update:
> + dl_se->deadline = rq->clock + dl_se->dl_deadline;
> + dl_se->runtime = dl_se->dl_runtime;
> + }
> +}
We could write that as:
if (dl_time_before(dl_se, rq->clock) ||
!dl_check_bandwidth(dl_se, rq->clock)) {
/* reset parameters */
}
Also, I was wondering about a more descriptive name for
dl_check_bandwidth(), check _what_ about the bandwidth!?
dl_bandwidth_overflow() perhaps, that would also remove that negation.
next prev parent reply other threads:[~2010-04-13 18:22 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-28 19:06 [RFC][PATCH 0/11] sched: SCHED_DEADLINE v2 Raistlin
2010-02-28 19:15 ` [RFC][PATCH 01/11] sched: add sched_class->task_dead Raistlin
2010-02-28 19:17 ` [RFC][PATCH 02/11] sched: SCHED_DEADLINE policy implementation Raistlin
2010-04-13 18:22 ` Peter Zijlstra
2010-04-13 18:22 ` Peter Zijlstra
2010-04-13 18:22 ` Peter Zijlstra
2010-04-13 18:55 ` Steven Rostedt
2010-04-15 7:34 ` Peter Zijlstra
2010-04-13 18:22 ` Peter Zijlstra [this message]
2010-04-13 18:22 ` Peter Zijlstra
2010-02-28 19:18 ` [RFC][PATCH 03/11] sched: add extended scheduling interface Raistlin
2010-02-28 19:19 ` [RFC][PATCH 04/11] sched: add resource limits for -deadline tasks Raistlin
2010-02-28 19:20 ` [RFC][PATCH 05/11] sched: add a syscall to wait for the next instance Raistlin
2010-02-28 19:22 ` [RFC][PATCH 06/11] sched: add the sched-debug bits for sched_dl Raistlin
2010-02-28 19:23 ` [RFC][PATCH 07/11] sched: add latency tracing for -deadline tasks Raistlin
2010-02-28 19:24 ` [RFC][PATCH 08/11] sched: send SIGXCPU at -deadline task overruns Raistlin
2010-04-13 18:22 ` Peter Zijlstra
2010-04-13 19:32 ` Oleg Nesterov
2010-02-28 19:26 ` [RFC][PATCH 09/11] sched: first draft of deadline inheritance Raistlin
2010-04-14 8:25 ` Peter Zijlstra
2010-04-14 9:45 ` Peter Zijlstra
2010-02-28 19:27 ` [RFC][PATCH 10/11] sched: add bandwidth management for sched_dl Raistlin
2010-04-14 10:09 ` Peter Zijlstra
2010-02-28 19:28 ` [RFC][PATCH 11/11] sched: add sched_dl documentation Raistlin
2010-04-14 10:17 ` [RFC][PATCH 0/11] sched: SCHED_DEADLINE v2 Peter Zijlstra
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