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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 B4E5DC432C0 for ; Tue, 3 Dec 2019 16:01:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D100206E4 for ; Tue, 3 Dec 2019 16:01:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575388890; bh=UYQUIS4VEh9FgjKXlL/TghxQGzex5f/+EUkRGQy7vzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QazfKG2E4h5d/mW2OKPKYY7+63JpJ8TdZKU8vulon5j7UVCaCz2gbJwiKsDipi4Qq 9DGBNhPZ8/lfzmuwhSBDQr2TYR0+qkbdOskI1f6X44gSWSUTkMttzGMeYruk+SvI11 wLVzgBM/GWoI04EUY3uKyQxFi1vtICO4k38SYps4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727004AbfLCQB3 (ORCPT ); Tue, 3 Dec 2019 11:01:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:54096 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726822AbfLCQB0 (ORCPT ); Tue, 3 Dec 2019 11:01:26 -0500 Received: from lenoir.home (lfbn-ncy-1-150-155.w83-194.abo.wanadoo.fr [83.194.232.155]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B040A20803; Tue, 3 Dec 2019 16:01:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575388886; bh=UYQUIS4VEh9FgjKXlL/TghxQGzex5f/+EUkRGQy7vzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KMQQy47m22EVQ2Nu7sKQPWT0kJ+SzD1yKxNkhBRG3Uhmuti3+pRD+H4uKx5Aq0tM/ MuBng/iGTK1RACBGDZsYrRAdQvS++wroZK/Qkf6JaLeOsN6IucIaOKl84fM2VoENau 7Jqb3sNL1Fw4oQ5celiX0Ql5utbIzDtnQD6RHiHY= From: Frederic Weisbecker To: Ingo Molnar , Peter Zijlstra Cc: LKML , Frederic Weisbecker Subject: [PATCH 2/2] sched: Use fair:prio_changed() instead of ad-hoc implementation Date: Tue, 3 Dec 2019 17:01:06 +0100 Message-Id: <20191203160106.18806-3-frederic@kernel.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191203160106.18806-1-frederic@kernel.org> References: <20191203160106.18806-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org set_user_nice() implements its own version of fair::prio_changed() and therefore misses a specific optimization towards nohz_full CPUs that avoid sending an resched IPI to a reniced task running alone. Use the proper callback instead. Reported-by: Peter Zijlstra Signed-off-by: Frederic Weisbecker --- kernel/sched/core.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 90e4b00ace89..66d1af94455e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4540,17 +4540,17 @@ void set_user_nice(struct task_struct *p, long nice) p->prio = effective_prio(p); delta = p->prio - old_prio; - if (queued) { + if (queued) enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK); - /* - * If the task increased its priority or is running and - * lowered its priority, then reschedule its CPU: - */ - if (delta < 0 || (delta > 0 && task_running(rq, p))) - resched_curr(rq); - } + if (running) set_next_task(rq, p); + /* + * If the task increased its priority or is running and + * lowered its priority, then reschedule its CPU: + */ + p->sched_class->prio_changed(rq, p, old_prio); + out_unlock: task_rq_unlock(rq, p, &rf); } -- 2.23.0