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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B115AC54EBE for ; Mon, 16 Jan 2023 11:19:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229995AbjAPLTs (ORCPT ); Mon, 16 Jan 2023 06:19:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230358AbjAPLTe (ORCPT ); Mon, 16 Jan 2023 06:19:34 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9749165A0 for ; Mon, 16 Jan 2023 03:19:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=K5M7ZAEyaWW+WNHWn0Ib+GABLC2gPGGPJYlg1grcpoo=; b=uQe+ocC7Zpc4c3eFhyJT7dIPGV pPxD0Kgy50UxgHuqVaU9Grkg514zAH8mGJYRIAn01moNsIQvdbykNzQwVK9s738IK3zgY22TNcg1d MYT6cl3tnxGFlukIoj2hIqdF3zrbY+l0eGqvYs8b4diqodql8AYN7Iok85lXoMxndTqNq5PivT42d OQpomAaEsBrhF3UgIawOURE7ce7zd1jE/eRD3Ba6N3qLcbGIyx3hrOuN0wBz+LXwe0gLZ+iVVHrRq 8XgxcA/SCJ5/6dH2gHiOKrtAowar4v2nEUje74QGbM1xIeq2vDdwXjTHbySotWku1jqfZ1BOBKJtO yJuN/63g==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pHNWM-008gA2-NF; Mon, 16 Jan 2023 11:19:23 +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 (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 42D0A300193; Mon, 16 Jan 2023 12:19:07 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id EE64F2081B293; Mon, 16 Jan 2023 12:19:06 +0100 (CET) Date: Mon, 16 Jan 2023 12:19:06 +0100 From: Peter Zijlstra To: Hao Jia Cc: mingo@redhat.com, mingo@kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mgorman@techsingularity.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched/core: Avoid WARN_DOUBLE_CLOCK warning when CONFIG_SCHED_CORE Message-ID: References: <20221206070550.31763-1-jiahao.os@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221206070550.31763-1-jiahao.os@bytedance.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 06, 2022 at 03:05:50PM +0800, Hao Jia wrote: > When we need to call update_rq_clock() to update the rq clock of > other CPUs on the same core, before that we need to clear RQCF_UPDATED > of rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning. > Because at this time the rq->clock_update_flags of other CPUs > may be RQCF_UPDATED. So you've found that the WARN_DOUBLE_CLOCK machinery doesn't work for core-sched -- but then instead of fixing that machinery, you put band-aids on it :/