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=-11.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 43F21C07E96 for ; Thu, 8 Jul 2021 10:26:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 270D961452 for ; Thu, 8 Jul 2021 10:26:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231486AbhGHK32 (ORCPT ); Thu, 8 Jul 2021 06:29:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231332AbhGHK31 (ORCPT ); Thu, 8 Jul 2021 06:29:27 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9D84C061574 for ; Thu, 8 Jul 2021 03:26:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=W6daYrP8Mv2FprAvKbzd+kl8kAFrmodDnM6Y2UgE6zs=; b=LGrhXEsYfyPCIkU5Lhlbt3mzrD nPYY0+/5sDwdJPwG58wKYZPDFGLezlg3zHxn8fC4X3clhB6TD7fcQI8ou1fBX3dbf/J/t3rvbukOl Jlk8J5GTwtFNI/Qn61q3yjZCkgeANb9diAjzU1EmawY5VRwYW5GLcZg2w5m4tn3Yh0lfk4T1jgd09 vNpmcNWlNz1F3q6eYZ1G3AgY4efkh1EOiaFcadjeyFYhOy/fDXK/2vm76Bg8g3Z3tQUwYbctOAATS lIBq5OWzvWmi3/ANeFHSyUgpwtA//2HzRLJhRzJijJheD0u5ipDoytUBjn3Lv2VhnUJdHrwb2xlhY +uwvrPcQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1m1REo-00FbhV-EJ; Thu, 08 Jul 2021 10:26:34 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 5A059300233; Thu, 8 Jul 2021 12:26:33 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 384992CB6EA9B; Thu, 8 Jul 2021 12:26:33 +0200 (CEST) Date: Thu, 8 Jul 2021 12:26:33 +0200 From: Peter Zijlstra To: Juri Lelli Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, vincent.guittot@linaro.org, rostedt@goodmis.org, dietmar.eggemann@arm.com, bristot@redhat.com, bsegall@google.com, mgorman@suse.de, Mark Simmons Subject: Re: [PATCH] sched/rt: Fix double enqueue caused by rt_effective_prio Message-ID: References: <20210701091431.256457-1-juri.lelli@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 08, 2021 at 12:06:27PM +0200, Peter Zijlstra wrote: > Slightly larger patch, but perhaps a little cleaner.. still pondering if > we can share a little more between __sched_setscheduler() and > rt_mutex_setprio(). Best I can seem to come up with... --- kernel/sched/core.c | 45 +++++++++++++++++---------------------------- 1 file changed, 17 insertions(+), 28 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ede10642612c..c686f0c70656 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6341,6 +6341,18 @@ int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flag } EXPORT_SYMBOL(default_wake_function); +static void __setscheduler_prio(struct task_struct *p, int prio) +{ + if (dl_prio(prio)) + p->sched_class = &dl_sched_class; + else if (rt_prio(prio)) + p->sched_class = &rt_sched_class; + else + p->sched_class = &fair_sched_class; + + p->prio = prio; +} + #ifdef CONFIG_RT_MUTEXES static inline int __rt_effective_prio(struct task_struct *pi_task, int prio) @@ -6456,22 +6468,19 @@ void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) } else { p->dl.pi_se = &p->dl; } - p->sched_class = &dl_sched_class; } else if (rt_prio(prio)) { if (dl_prio(oldprio)) p->dl.pi_se = &p->dl; if (oldprio < prio) queue_flag |= ENQUEUE_HEAD; - p->sched_class = &rt_sched_class; } else { if (dl_prio(oldprio)) p->dl.pi_se = &p->dl; if (rt_prio(oldprio)) p->rt.timeout = 0; - p->sched_class = &fair_sched_class; } - p->prio = prio; + __setscheduler_prio(p, prio); if (queued) enqueue_task(rq, p, queue_flag); @@ -6824,29 +6833,6 @@ static void __setscheduler_params(struct task_struct *p, set_load_weight(p, true); } -/* Actually do priority change: must hold pi & rq lock. */ -static void __setscheduler(struct rq *rq, struct task_struct *p, - const struct sched_attr *attr, int newprio) -{ - /* - * If params can't change scheduling class changes aren't allowed - * either. - */ - if (attr->sched_flags & SCHED_FLAG_KEEP_PARAMS) - return; - - __setscheduler_params(p, attr); - - p->prio = newprio; - - if (dl_prio(p->prio)) - p->sched_class = &dl_sched_class; - else if (rt_prio(p->prio)) - p->sched_class = &rt_sched_class; - else - p->sched_class = &fair_sched_class; -} - /* * Check the target process has a UID that matches the current process's: */ @@ -7089,7 +7075,10 @@ static int __sched_setscheduler(struct task_struct *p, prev_class = p->sched_class; - __setscheduler(rq, p, attr, newprio); + if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) { + __setscheduler_params(p, attr); + __setscheduler_prio(p, newprio); + } __setscheduler_uclamp(p, attr); if (queued) {