From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5A4832D661F; Thu, 10 Jul 2025 10:13:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752142406; cv=none; b=XI+UCjbmofGxfXvsXpdBCJkRVvhkB2V5ODjxNPpUmvKMG5BZLegAM1j6T1izny0CM4gFNGeYo0guMQ5wa63EnAsaesNzyobArqjpy72++l43WckOZu7dsSGHujA1Epi1q17y8G64FqVTNLWw7K4LOuUI+anvFi4EIAu3JF4khgs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752142406; c=relaxed/simple; bh=F9Zn38Ia5P+j2FJQVJkhDRVVfMYoxSFosPDOuypiIMA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VoqhT2ECSbsTiB47+X+lmrZjcb4GnywhiREMJ0Gf4PwXgPIjmuSsoE85tO3A9lLuV9c7kfTaR8WOebwM/F3JtbLeye7R9P0gVWyO/cZtsgA4+MAJd6WHCrVh+scKUsJ2W2/hawxJbg9Z6/fovrPq3mbUeyOiYGEFGnWFm76cpcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=RadJuAWg; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="RadJuAWg" 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=ENYhfh0yC13BHVhZjvhSu3orUCwcKZQ5QjaaRVv3TS4=; b=RadJuAWgSyMYaLX8M7SGTm5T7v LZaYlLHu5zA2FYrYvjLwRFAjjh8xZAS5uEizug0oqKd10Ybnfw1zt0kdsGIopqn8e9e6egwke6bQo fRjArkm0xUiErhdJCWUy3mvnap9Mx8FQCO92a0rapwUmoPXQxl5Irxh4+s7MEgyW2JCHI/+aacXxn NtYO5aYS7RBx67Mg0J5F4CcCMzzS/wBg7cTvBO/PHLeZ9zEhDVVGJF6zcsXcLFl7j5pfBv8eNRU/M gPgqGbn6fV+Hhv3Jg2VLdTtD4pc5ypw4B8QMjIbeicwe/CE89+Yi1lQ+l990Jht0IUI/n3caLYY9X zdbTKUSw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uZoHF-00000008Rvt-053y; Thu, 10 Jul 2025 10:13:17 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 9720030023C; Thu, 10 Jul 2025 12:13:16 +0200 (CEST) Date: Thu, 10 Jul 2025 12:13:16 +0200 From: Peter Zijlstra To: "Chen, Yu C" Cc: Sebastian Andrzej Siewior , Ingo Molnar , kernel test robot , oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, x86@kernel.org, Dietmar Eggemann , Juri Lelli , Linus Torvalds , Mel Gorman , Shrikanth Hegde , Steven Rostedt , Valentin Schneider , Vincent Guittot , aubrey.li@linux.intel.com Subject: Re: [PATCH] lib/smp_processor_id: Make migration check unconditional of SMP Message-ID: <20250710101316.GJ1613376@noisy.programming.kicks-ass.net> References: <202507100448.6b88d6f1-lkp@intel.com> <6cf071f3-ff5b-4025-8ce7-2f2cceb03984@intel.com> <20250710062528.T-Obm39T@linutronix.de> <292e70ed-aae5-4f52-8f85-80cba7ff301d@intel.com> <20250710081114.5wnABNG7@linutronix.de> <20250710082748.-DPO1rjO@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Jul 10, 2025 at 04:32:57PM +0800, Chen, Yu C wrote: > On 7/10/2025 4:27 PM, Sebastian Andrzej Siewior wrote: > > Commit cac5cefbade90 ("sched/smp: Make SMP unconditional") > > migrate_disable() even on UP builds. > > Commit 06ddd17521bf1 ("sched/smp: Always define is_percpu_thread() and > > scheduler_ipi()") made is_percpu_thread() check the affinity mask > > instead replying always true for UP mask. > > > > As a consequence smp_processor_id() now complains if invoked within a > > migrate_disable() section because is_percpu_thread() checks its mask and > > the migration check is left out. > > > > Make migration check unconditional of SMP. > > > > Fixes: cac5cefbade90 ("sched/smp: Make SMP unconditional") > > Reported-by: kernel test robot > > Closes: https://lore.kernel.org/oe-lkp/202507100448.6b88d6f1-lkp@intel.com > > Signed-off-by: Sebastian Andrzej Siewior > > --- > > From my understanding, > > Reviewed-by: Chen Yu Thanks; let me go stick this in a tree somewhere.