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=-10.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 3A49DC433FE for ; Thu, 3 Dec 2020 17:12:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5640207B0 for ; Thu, 3 Dec 2020 17:12:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731513AbgLCRLu (ORCPT ); Thu, 3 Dec 2020 12:11:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726257AbgLCRLt (ORCPT ); Thu, 3 Dec 2020 12:11:49 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E614C061A54; Thu, 3 Dec 2020 09:10:48 -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=0lhCxHLgf8TSOAvypxgyZdt6AOtyZg3i7+GSOy69WwU=; b=jeeAqf558AfAqY1ZPTR4HfNgwX YopjYarSwRSdQuGeGyjCSNFpvTWHEYq7+8CHvDrMVdGazF9BvP9no40RR9phvvpP85cND+YTv5ln8 KPsTGbcRveY23zSbT4NayaXcOaWGv8eD84pD4++pebfb9TdeUpWsXFyBzsbMD+4DIqsHk8ZIrsRiW I7PtW3gWf5TUhQ5JidDUj/TGspfxPwztfLhtU0q/hd+wkoe4vNNFcR8XRjZIn82vi+bkd0ZTVcg/Z fo0RR2g2KJYGfC5KQ9XiTR/EvLYuZJdjOjJWpHZAgMtF0E4z09yRlsVs8vjqzUSCTdzo9+Ps9L8Qg SgThpYbg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kks7U-0000Aw-Oc; Thu, 03 Dec 2020 17:10:17 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 71A073059DD; Thu, 3 Dec 2020 18:10:15 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 5647C2029C718; Thu, 3 Dec 2020 18:10:15 +0100 (CET) Date: Thu, 3 Dec 2020 18:10:15 +0100 From: Peter Zijlstra To: Heiko Carstens Cc: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sven Schnelle , Mark Rutland , linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, uclinux-h8-devel@lists.sourceforge.jp, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org Subject: Re: [PATCH AUTOSEL 5.9 27/39] sched/idle: Fix arch_cpu_idle() vs tracing Message-ID: <20201203171015.GN2414@hirez.programming.kicks-ass.net> References: <20201203132834.930999-1-sashal@kernel.org> <20201203132834.930999-27-sashal@kernel.org> <20201203145442.GC9994@osiris> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201203145442.GC9994@osiris> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 03, 2020 at 03:54:42PM +0100, Heiko Carstens wrote: > On Thu, Dec 03, 2020 at 08:28:21AM -0500, Sasha Levin wrote: > > From: Peter Zijlstra > > > > [ Upstream commit 58c644ba512cfbc2e39b758dd979edd1d6d00e27 ] > > > > We call arch_cpu_idle() with RCU disabled, but then use > > local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. > > > > Switch all arch_cpu_idle() implementations to use > > raw_local_irq_{en,dis}able() and carefully manage the > > lockdep,rcu,tracing state like we do in entry. > > > > (XXX: we really should change arch_cpu_idle() to not return with > > interrupts enabled) > > > > Reported-by: Sven Schnelle > > Signed-off-by: Peter Zijlstra (Intel) > > Reviewed-by: Mark Rutland > > Tested-by: Mark Rutland > > Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org > > Signed-off-by: Sasha Levin > > This patch broke s390 irq state tracing. A patch to fix this is > scheduled to be merged upstream today (hopefully). > Therefore I think this patch should not yet go into 5.9 stable. Agreed.