From nobody Tue Dec 30 13:26:19 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A365C07548 for ; Wed, 15 Nov 2023 09:05:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234733AbjKOJFY (ORCPT ); Wed, 15 Nov 2023 04:05:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234720AbjKOJFB (ORCPT ); Wed, 15 Nov 2023 04:05:01 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27FDE120; Wed, 15 Nov 2023 01:04:58 -0800 (PST) Date: Wed, 15 Nov 2023 09:04:56 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1700039096; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RLOytOKGBnb6B6iJmpeTnDki+l9w/n1XwObQHovifBs=; b=PrzolQA+m5jo/hrKeMdyMgGQPJUMxcOFUbgxFPb0/ViRvNCeoKpE/08kFEy9dMC+323Vxm XKwRQqAbOif4z7cgleZonVX4ONnJw+wj+T1h86+fcrlq3xh1NH3kON2EqAJZG1gwoNNLSu 8re8R7bVVyu4d/sj+N8Gh+wzwstGbA9EObgwFe44nIo1kuDpFaUaVt9YANtloeZgttA9Dw LRNhB0/oNa3Yz4wXb+p/JtFjTfyErKJFRyIDUOBQkbC9oZL21aGteLaJwrGi2PDc65d09g priLf+9ssVuQaA1ti2CwkcgyS/iEbsd48zJ7EHrh9OyVilFJ/mt52oaCcZVQLA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1700039096; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RLOytOKGBnb6B6iJmpeTnDki+l9w/n1XwObQHovifBs=; b=igLiwJk5GVFqc2Kx5uJ0OuPxYuQVWIocZ3L9201Mx90oWfsXfyPEbpy+fHODpV8qOP+F4X Qcyw5Xqf0PvUHcAw== From: "tip-bot2 for Paul E. McKenney" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched: Use WRITE_ONCE() for p->on_rq Cc: "Paul E. McKenney" , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: MIME-Version: 1.0 Message-ID: <170003909617.391.3174076166121466906.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: d6111cf45c5787282b2e20d77bdb6b28881d516a Gitweb: https://git.kernel.org/tip/d6111cf45c5787282b2e20d77bdb6b288= 81d516a Author: Paul E. McKenney AuthorDate: Tue, 31 Oct 2023 11:12:01 -07:00 Committer: Peter Zijlstra CommitterDate: Wed, 15 Nov 2023 09:57:45 +01:00 sched: Use WRITE_ONCE() for p->on_rq Since RCU-tasks uses READ_ONCE(p->on_rq), ensure the write-side matches with WRITE_ONCE(). Signed-off-by: "Paul E. McKenney" Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/e4896e0b-eacc-45a2-a7a8-de2280a51ecc@paulmc= k-laptop --- kernel/sched/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a708d22..9d5099d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2124,12 +2124,14 @@ void activate_task(struct rq *rq, struct task_struc= t *p, int flags) =20 enqueue_task(rq, p, flags); =20 - p->on_rq =3D TASK_ON_RQ_QUEUED; + WRITE_ONCE(p->on_rq, TASK_ON_RQ_QUEUED); + ASSERT_EXCLUSIVE_WRITER(p->on_rq); } =20 void deactivate_task(struct rq *rq, struct task_struct *p, int flags) { - p->on_rq =3D (flags & DEQUEUE_SLEEP) ? 0 : TASK_ON_RQ_MIGRATING; + WRITE_ONCE(p->on_rq, (flags & DEQUEUE_SLEEP) ? 0 : TASK_ON_RQ_MIGRATING); + ASSERT_EXCLUSIVE_WRITER(p->on_rq); =20 dequeue_task(rq, p, flags); }