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 E6F8DE732E3 for ; Thu, 28 Sep 2023 15:19:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231743AbjI1PTh (ORCPT ); Thu, 28 Sep 2023 11:19:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231451AbjI1PTf (ORCPT ); Thu, 28 Sep 2023 11:19:35 -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 B4022AC for ; Thu, 28 Sep 2023 08:19:33 -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=5hV9RHE2np4Q/chcyiz0z8ahVkd4d/jzh2cotT+E4Ik=; b=JBXepoFRBRKckRrMLqnelG5jyB iR1XVar5xlG5UqiTkMBAHBGTe1+MCdNP/ZUjQ3wKGsh2FBBtSC7lIxwPbMYljCoyfv0/MQQbmCSxc ZZzCk/Tfoc4NAtENKmajrceMBCdgwPzCWFlSQkwH0ts1yUJurcJSeDeO1wm2C5LfmF3DCihEDSybn gO8vuygiALgyNQgRvTWuCOhMxqM0poVeiq2NFCiM7kA+ptZt2JZ+EfPn4YJ8sxZoR59/0IP67wlKd GbTv7VDYcnz2nLOF1tv+dVuKlefK0NMbDLxskWOoaCUaYeY/5suC5YaxT5MTGKU+J7CWBZ5BpEooQ 10bPzCRQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qlsnM-0057CY-0X; Thu, 28 Sep 2023 15:19:17 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 46C453002E3; Thu, 28 Sep 2023 17:19:17 +0200 (CEST) Date: Thu, 28 Sep 2023 17:19:17 +0200 From: Peter Zijlstra To: Kuyo Chang =?utf-8?B?KOW8teW7uuaWhyk=?= Cc: "dietmar.eggemann@arm.com" , "linux-kernel@vger.kernel.org" , "linux-mediatek@lists.infradead.org" , "rostedt@goodmis.org" , wsd_upstream , "vschneid@redhat.com" , "bristot@redhat.com" , "juri.lelli@redhat.com" , "mingo@redhat.com" , "linux-arm-kernel@lists.infradead.org" , "bsegall@google.com" , "mgorman@suse.de" , "matthias.bgg@gmail.com" , "vincent.guittot@linaro.org" , "angelogioacchino.delregno@collabora.com" Subject: Re: [PATCH 1/1] sched/core: Fix stuck on completion for affine_move_task() when stopper disable Message-ID: <20230928151917.GB29651@noisy.programming.kicks-ass.net> References: <20230927033431.12406-1-kuyo.chang@mediatek.com> <20230927080850.GB21824@noisy.programming.kicks-ass.net> <20230928151616.GD27245@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230928151616.GD27245@noisy.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 28, 2023 at 05:16:16PM +0200, Peter Zijlstra wrote: > AFAICT this is migrate_enable(), which acts on current, so how can the > CPU that current runs on go away? > Your patch has at least one very obvious resource leak. Sorry those are not so, I ended up staring at the wrong stop_one_cpu_nowait() :-/ Still, the rest is very much the case, if you can't describe the exact race scenario, you can't be talking about a solution.