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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 E7C7AC64E7B for ; Mon, 30 Nov 2020 12:02:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3A875206D8 for ; Mon, 30 Nov 2020 12:02:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="qyUqSFAw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A875206D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4F2736B0036; Mon, 30 Nov 2020 07:02:47 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4A2EC8D0002; Mon, 30 Nov 2020 07:02:47 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3919D8D0001; Mon, 30 Nov 2020 07:02:47 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0137.hostedemail.com [216.40.44.137]) by kanga.kvack.org (Postfix) with ESMTP id 234546B0036 for ; Mon, 30 Nov 2020 07:02:47 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id E01BB248F for ; Mon, 30 Nov 2020 12:02:46 +0000 (UTC) X-FDA: 77540947932.29.order20_071256d273a1 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id ABCEC180868EC for ; Mon, 30 Nov 2020 12:02:46 +0000 (UTC) X-HE-Tag: order20_071256d273a1 X-Filterd-Recvd-Size: 3242 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Mon, 30 Nov 2020 12:02:46 +0000 (UTC) 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=KL150PBytFacvb1Rx83FKzZm9c1fzyGio28tBtynuTo=; b=qyUqSFAwzXrYDOunjEvrfNhG8d 50KvhMPES/lze9lxXtuugMe4dh4kGGJlL43PqN/onGzowMSmekgTj7+yAZxhIZkYPDhuV8sJw47oY sfcMeFtiG4Je1L3dseNBfoG+2knmjvpqgOfWL2CSUP52YWZDFYW5DjRWnFc02XQXPfYv6CDHtH90k zOykrIzUKV/r8bCFxeR3hOxHgdHTn5iUej0KdbsJRe8eZffeVjx7DLZHXFEgBgN9bntr4uJXH4lYS /wTGCYpZZVwUzVPRnYNWOynjWmPAkDVlOcFSe8RHp+/v1niZCN5eUjp8J6/6oZzUWOy+tgJgGywml cNctm84w==; 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 1kjhtC-0000VM-Qj; Mon, 30 Nov 2020 12:02:43 +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 B32E3300DAE; Mon, 30 Nov 2020 13:02:41 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9F1AE233D604D; Mon, 30 Nov 2020 13:02:41 +0100 (CET) Date: Mon, 30 Nov 2020 13:02:41 +0100 From: Peter Zijlstra To: Vlastimil Babka Cc: Mohamed Alzayat , "Aneesh Kumar K.V" , linux-mm@kvack.org, Will Deacon Subject: Re: Potential bug in soft-dirty bits (with test case) Message-ID: <20201130120241.GP3040@hirez.programming.kicks-ass.net> References: <2e60ad6d-7bdf-e19e-4ad9-6942f76088d3@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2e60ad6d-7bdf-e19e-4ad9-6942f76088d3@suse.cz> 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 Mon, Nov 30, 2020 at 12:51:59PM +0100, Vlastimil Babka wrote: > On 11/30/20 11:37 AM, Mohamed Alzayat wrote: > > Thanks for confirming, Vlastimil! > > > > The first bad commit is: 0758cd8304942292e95a0f750c374533db378b32 > > asm-generic/tlb: avoid potential double flush > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0758cd8304942292e95a0f750c374533db378b32 > > > > Reverting this commit solves the problem, but this might not be the > > right way of fixing it. > > Thanks for bisecting! Let's CC people involved in that commit. All important > should be in the quoted conversation above. There's a thread about it here: https://lkml.kernel.org/r/20201120143557.6715-1-will@kernel.org That softdirty code really shouldn't be using mmu_gather imo, but I'm still not clear on what exactly is broken why there.