From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4691AC43381 for ; Mon, 18 Feb 2019 17:40:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E7212085A for ; Mon, 18 Feb 2019 17:40:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="EI4Xo4R0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389420AbfBRRkr (ORCPT ); Mon, 18 Feb 2019 12:40:47 -0500 Received: from merlin.infradead.org ([205.233.59.134]:47710 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388990AbfBRRki (ORCPT ); Mon, 18 Feb 2019 12:40:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=uM0ZWUoum7E8t4f6OYHHgc13deTWanDlcXfF9qflM+g=; b=EI4Xo4R0zozvF5t4ZbKfQPjeLD eu3pfGvodv5HeWD5TvGFVwuVnveZ67BWHJay7tDj2umIl3ldltaJXsKB5sEc2E3utplumEr2sgtnB ys6L8p3d+s+XpWERahTqjmInTv3B0YtMLKQkZl7IvlkZuNx02AryPGyvPLKf1ZJ0i1MJ/ecHJISq0 nGhYvgx4VmyJeLB9x9tXVvelpJtOYDulAQE2xJDdELj/MJUbjCIR1u/Ptchw6M774pq63d9D4Tb3A uvmEl9srH3ftGLwURj+h+XGEz6YYMdqjdJ4rtknVfIpsnfEWJz4QC0a2Ri787El7h73mDVPm3GGwq Y9eEqrTg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gvmu2-0001Ex-GM; Mon, 18 Feb 2019 17:40:26 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 339452848B87B; Mon, 18 Feb 2019 18:40:23 +0100 (CET) Message-Id: <20190218173514.418814864@infradead.org> User-Agent: quilt/0.65 Date: Mon, 18 Feb 2019 17:56:29 +0100 From: Peter Zijlstra To: mingo@kernel.org, tglx@linutronix.de, pjt@google.com, tim.c.chen@linux.intel.com, torvalds@linux-foundation.org Cc: linux-kernel@vger.kernel.org, subhra.mazumdar@oracle.com, fweisbec@gmail.com, keescook@chromium.org, kerrnel@google.com, "Peter Zijlstra (Intel)" Subject: [RFC][PATCH 09/16] sched: Introduce sched_class::pick_task() References: <20190218165620.383905466@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Because sched_class::pick_next_task() also implies sched_class::set_next_task() (and possibly put_prev_task() and newidle_balance) it is not state invariant. This makes it unsuitable for remote task selection. Signed-off-by: Peter Zijlstra (Intel) --- kernel/sched/deadline.c | 21 ++++++++++++++++----- kernel/sched/fair.c | 30 ++++++++++++++++++++++++++++++ kernel/sched/idle.c | 10 +++++++++- kernel/sched/rt.c | 21 ++++++++++++++++----- kernel/sched/sched.h | 2 ++ kernel/sched/stop_task.c | 21 ++++++++++++++++----- 6 files changed, 89 insertions(+), 16 deletions(-) --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1723,15 +1723,12 @@ static struct sched_dl_entity *pick_next return rb_entry(left, struct sched_dl_entity, rb_node); } -static struct task_struct * -pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +static struct task_struct *pick_task_dl(struct rq *rq) { struct sched_dl_entity *dl_se; struct task_struct *p; struct dl_rq *dl_rq; - WARN_ON_ONCE(prev || rf); - dl_rq = &rq->dl; if (unlikely(!dl_rq->dl_nr_running)) @@ -1742,7 +1739,19 @@ pick_next_task_dl(struct rq *rq, struct p = dl_task_of(dl_se); - set_next_task_dl(rq, p); + return p; +} + +static struct task_struct * +pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +{ + struct task_struct *p; + + WARN_ON_ONCE(prev || rf); + + p = pick_task_dl(rq); + if (p) + set_next_task_dl(rq, p); return p; } @@ -2389,6 +2398,8 @@ const struct sched_class dl_sched_class .set_next_task = set_next_task_dl, #ifdef CONFIG_SMP + .pick_task = pick_task_dl, + .select_task_rq = select_task_rq_dl, .migrate_task_rq = migrate_task_rq_dl, .set_cpus_allowed = set_cpus_allowed_dl, --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6937,6 +6937,34 @@ static void check_preempt_wakeup(struct } static struct task_struct * +pick_task_fair(struct rq *rq) +{ + struct cfs_rq *cfs_rq = &rq->cfs; + struct sched_entity *se; + + if (!cfs_rq->nr_running) + return NULL; + + do { + struct sched_entity *curr = cfs_rq->curr; + + se = pick_next_entity(cfs_rq, NULL); + + if (curr) { + if (se && curr->on_rq) + update_curr(cfs_rq); + + if (!se || entity_before(curr, se)) + se = curr; + } + + cfs_rq = group_cfs_rq(se); + } while (cfs_rq); + + return task_of(se); +} + +static struct task_struct * pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { struct cfs_rq *cfs_rq = &rq->cfs; @@ -10604,6 +10632,8 @@ const struct sched_class fair_sched_clas .set_next_task = set_next_task_fair, #ifdef CONFIG_SMP + .pick_task = pick_task_fair, + .select_task_rq = select_task_rq_fair, .migrate_task_rq = migrate_task_rq_fair, --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -373,6 +373,12 @@ static void check_preempt_curr_idle(stru resched_curr(rq); } +static struct task_struct * +pick_task_idle(struct rq *rq) +{ + return rq->idle; +} + static void put_prev_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { } @@ -386,11 +392,12 @@ static void set_next_task_idle(struct rq static struct task_struct * pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) { - struct task_struct *next = rq->idle; + struct task_struct *next; if (prev) put_prev_task(rq, prev); + next = pick_task_idle(rq); set_next_task_idle(rq, next); return next; @@ -458,6 +465,7 @@ const struct sched_class idle_sched_clas .set_next_task = set_next_task_idle, #ifdef CONFIG_SMP + .pick_task = pick_task_idle, .select_task_rq = select_task_rq_idle, .set_cpus_allowed = set_cpus_allowed_common, #endif --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1548,20 +1548,29 @@ static struct task_struct *_pick_next_ta return rt_task_of(rt_se); } -static struct task_struct * -pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +static struct task_struct *pick_task_rt(struct rq *rq) { struct task_struct *p; struct rt_rq *rt_rq = &rq->rt; - WARN_ON_ONCE(prev || rf); - if (!rt_rq->rt_queued) return NULL; p = _pick_next_task_rt(rq); - set_next_task_rt(rq, p); + return p; +} + +static struct task_struct * +pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +{ + struct task_struct *p; + + WARN_ON_ONCE(prev || rf); + + p = pick_task_rt(rq); + if (p) + set_next_task_rt(rq, p); return p; } @@ -2364,6 +2373,8 @@ const struct sched_class rt_sched_class .set_next_task = set_next_task_rt, #ifdef CONFIG_SMP + .pick_task = pick_task_rt, + .select_task_rq = select_task_rq_rt, .set_cpus_allowed = set_cpus_allowed_common, --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1682,6 +1682,8 @@ struct sched_class { void (*set_next_task)(struct rq *rq, struct task_struct *p); #ifdef CONFIG_SMP + struct task_struct * (*pick_task)(struct rq *rq); + int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags); void (*migrate_task_rq)(struct task_struct *p, int new_cpu); --- a/kernel/sched/stop_task.c +++ b/kernel/sched/stop_task.c @@ -29,20 +29,30 @@ static void set_next_task_stop(struct rq } static struct task_struct * -pick_next_task_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +pick_task_stop(struct rq *rq) { struct task_struct *stop = rq->stop; - WARN_ON_ONCE(prev || rf); - if (!stop || !task_on_rq_queued(stop)) return NULL; - set_next_task_stop(rq, stop); - return stop; } +static struct task_struct * +pick_next_task_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +{ + struct task_struct *p; + + WARN_ON_ONCE(prev || rf); + + p = pick_task_stop(rq); + if (p) + set_next_task_stop(rq, p); + + return p; +} + static void enqueue_task_stop(struct rq *rq, struct task_struct *p, int flags) { @@ -129,6 +139,7 @@ const struct sched_class stop_sched_clas .set_next_task = set_next_task_stop, #ifdef CONFIG_SMP + .pick_task = pick_task_stop, .select_task_rq = select_task_rq_stop, .set_cpus_allowed = set_cpus_allowed_common, #endif