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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 F3EA1C33CB2 for ; Tue, 14 Jan 2020 21:34:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9A13024679 for ; Tue, 14 Jan 2020 21:34:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="E19ztN87" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9A13024679 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 073578E0005; Tue, 14 Jan 2020 16:34:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F3DCF8E0003; Tue, 14 Jan 2020 16:34:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E06268E0005; Tue, 14 Jan 2020 16:34:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0044.hostedemail.com [216.40.44.44]) by kanga.kvack.org (Postfix) with ESMTP id C76928E0003 for ; Tue, 14 Jan 2020 16:34:07 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 44CE12C07 for ; Tue, 14 Jan 2020 21:34:07 +0000 (UTC) X-FDA: 76377542934.12.owner69_5e1c86f7bd048 X-HE-Tag: owner69_5e1c86f7bd048 X-Filterd-Recvd-Size: 4442 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Tue, 14 Jan 2020 21:34:06 +0000 (UTC) Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A7F3924656; Tue, 14 Jan 2020 21:34:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579037645; bh=N2S7y+O790zET1Gmtmsm8tuXTXxczW82v07Ij9f4etg=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=E19ztN87s0hx9TSeFhbYpD4KDYFnyV2gto/gqjaKAfYjz7c5aXHcsklLFATfRh40W Krlsmw3JOJcH2iti5LhYFL3x8wnsI4XrND8lAwIc7zpyl15esGA5KHG4rQs7yW5iyD XuiqPr1+p+/FgPX/3BzIPVbdApiWI0BuJYOa6yYg= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 597AF3522755; Tue, 14 Jan 2020 13:34:05 -0800 (PST) Date: Tue, 14 Jan 2020 13:34:05 -0800 From: "Paul E. McKenney" To: Qian Cai Cc: Marco Elver , LKMM Maintainers -- Akira Yokosawa , Alan Stern , Alexander Potapenko , Andrea Parri , Andrey Konovalov , Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Boqun Feng , Borislav Petkov , Daniel Axtens , Daniel Lustig , Dave Hansen , David Howells , Dmitry Vyukov , "H. Peter Anvin" , Ingo Molnar , Jade Alglave , Joel Fernandes , Jonathan Corbet , Josh Poimboeuf , Luc Maranget , Mark Rutland , Nicholas Piggin , Peter Zijlstra , Thomas Gleixner , Will Deacon , Eric Dumazet , kasan-dev , linux-arch , "open list:DOCUMENTATION" , linux-efi@vger.kernel.org, Linux Kbuild mailing list , LKML , Linux Memory Management List , the arch/x86 maintainers Subject: Re: [PATCH v4 01/10] kcsan: Add Kernel Concurrency Sanitizer infrastructure Message-ID: <20200114213405.GX2935@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200114192220.GS2935@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jan 14, 2020 at 03:30:53PM -0500, Qian Cai wrote: >=20 >=20 > > On Jan 14, 2020, at 2:22 PM, Paul E. McKenney wr= ote: > >=20 > > Just so I understand... Does this problem happen even in CONFIG_KCSA= N=3Dn > > kernels? >=20 > No. Whew!!! ;-) > > I have been running extensive CONFIG_KSCAN=3Dy rcutorture tests for q= uite > > awhile now, so even if this only happens for CONFIG_KSCAN=3Dy, it is = not > > like it affects everyone. > >=20 > > Yes, it should be fixed, and Marco does have a patch on the way. >=20 > The concern is really about setting KSCAN=3Dy in a distro debug kernel = where it has other debug options. I=E2=80=99ll try to dig into more of th= ose issues in the next few days. Understood. But there are likely to be other issues with KCSAN, given ho= w new it is. Yes, yes, I certainly would like to believe that the patches we currently know about will make KCSAN perfect for distros, I have way too much grey hair (and too little hair as well!) to really beleive that. As an alternative, once the patches needed for your tests to pass reach mainline, you could announce that KCSAN was ready to be enabled in distros. Though I confess that I don't know how that works. Is there a separate testing kernel binary provided by the distros in question? Thanx, Paul