Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754041AbcCHNSm (ORCPT ); Tue, 8 Mar 2016 08:18:42 -0500 Received: from torg.zytor.com ([198.137.202.12]:52052 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751833AbcCHNS0 (ORCPT ); Tue, 8 Mar 2016 08:18:26 -0500 Date: Tue, 8 Mar 2016 05:17:42 -0800 From: tip-bot for Luca Abeni Message-ID: Cc: peterz@infradead.org, mingo@kernel.org, torvalds@linux-foundation.org, luca.abeni@unitn.it, linux-kernel@vger.kernel.org, juri.lelli@arm.com, tglx@linutronix.de, hpa@zytor.com Reply-To: peterz@infradead.org, mingo@kernel.org, luca.abeni@unitn.it, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, juri.lelli@arm.com, tglx@linutronix.de, hpa@zytor.com In-Reply-To: <1457350024-7825-2-git-send-email-luca.abeni@unitn.it> References: <1457350024-7825-2-git-send-email-luca.abeni@unitn.it> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/deadline: Remove dl_new from struct sched_dl_entity Git-Commit-ID: 72f9f3fdc928dc3ecd223e801b32d930b662b6ed X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5401 Lines: 150 Commit-ID: 72f9f3fdc928dc3ecd223e801b32d930b662b6ed Gitweb: http://git.kernel.org/tip/72f9f3fdc928dc3ecd223e801b32d930b662b6ed Author: Luca Abeni AuthorDate: Mon, 7 Mar 2016 12:27:04 +0100 Committer: Ingo Molnar CommitDate: Tue, 8 Mar 2016 12:24:55 +0100 sched/deadline: Remove dl_new from struct sched_dl_entity The dl_new field of struct sched_dl_entity is currently used to identify new deadline tasks, so that their deadline and runtime can be properly initialised. However, these tasks can be easily identified by checking if their deadline is smaller than the current time when they switch to SCHED_DEADLINE. So, dl_new can be removed by introducing this check in switched_to_dl(); this allows to simplify the SCHED_DEADLINE code. Signed-off-by: Luca Abeni Signed-off-by: Peter Zijlstra (Intel) Cc: Juri Lelli Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1457350024-7825-2-git-send-email-luca.abeni@unitn.it Signed-off-by: Ingo Molnar --- include/linux/sched.h | 6 +----- kernel/sched/core.c | 1 - kernel/sched/deadline.c | 35 +++++++++++++---------------------- 3 files changed, 14 insertions(+), 28 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 9519b66..838a89a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1333,10 +1333,6 @@ struct sched_dl_entity { * task has to wait for a replenishment to be performed at the * next firing of dl_timer. * - * @dl_new tells if a new instance arrived. If so we must - * start executing it with full runtime and reset its absolute - * deadline; - * * @dl_boosted tells if we are boosted due to DI. If so we are * outside bandwidth enforcement mechanism (but only until we * exit the critical section); @@ -1344,7 +1340,7 @@ struct sched_dl_entity { * @dl_yielded tells if task gave up the cpu before consuming * all its available runtime during the last job. */ - int dl_throttled, dl_new, dl_boosted, dl_yielded; + int dl_throttled, dl_boosted, dl_yielded; /* * Bandwidth enforcement timer. Each -deadline task has its diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 423452c..249e37d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2051,7 +2051,6 @@ void __dl_clear_params(struct task_struct *p) dl_se->dl_bw = 0; dl_se->dl_throttled = 0; - dl_se->dl_new = 1; dl_se->dl_yielded = 0; } diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 15abf04..c7a036f 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -352,7 +352,15 @@ static inline void setup_new_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); - WARN_ON(!dl_se->dl_new || dl_se->dl_throttled); + WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline)); + + /* + * We are racing with the deadline timer. So, do nothing because + * the deadline timer handler will take care of properly recharging + * the runtime and postponing the deadline + */ + if (dl_se->dl_throttled) + return; /* * We use the regular wall clock time to set deadlines in the @@ -361,7 +369,6 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se, */ dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline; dl_se->runtime = pi_se->dl_runtime; - dl_se->dl_new = 0; } /* @@ -503,15 +510,6 @@ 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 instance needs special treatment, i.e., - * the actual scheduling parameters have to be "renewed". - */ - if (dl_se->dl_new) { - setup_new_dl_entity(dl_se, pi_se); - return; - } - if (dl_time_before(dl_se->deadline, rq_clock(rq)) || dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) { dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline; @@ -608,16 +606,6 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer) } /* - * This is possible if switched_from_dl() raced against a running - * callback that took the above !dl_task() path and we've since then - * switched back into SCHED_DEADLINE. - * - * There's nothing to do except drop our task reference. - */ - if (dl_se->dl_new) - goto unlock; - - /* * The task might have been boosted by someone else and might be in the * boosting/deboosting path, its not throttled. */ @@ -925,7 +913,7 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se, * parameters of the task might need updating. Otherwise, * we want a replenishment of its runtime. */ - if (dl_se->dl_new || flags & ENQUEUE_WAKEUP) + if (flags & ENQUEUE_WAKEUP) update_dl_entity(dl_se, pi_se); else if (flags & ENQUEUE_REPLENISH) replenish_dl_entity(dl_se, pi_se); @@ -1726,6 +1714,9 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p) */ static void switched_to_dl(struct rq *rq, struct task_struct *p) { + if (dl_time_before(p->dl.deadline, rq_clock(rq))) + setup_new_dl_entity(&p->dl, &p->dl); + if (task_on_rq_queued(p) && rq->curr != p) { #ifdef CONFIG_SMP if (p->nr_cpus_allowed > 1 && rq->dl.overloaded)