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 8AC74C433F5 for ; Thu, 12 May 2022 21:28:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358707AbiELV2h (ORCPT ); Thu, 12 May 2022 17:28:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343679AbiELV2g (ORCPT ); Thu, 12 May 2022 17:28:36 -0400 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02F201DE57D for ; Thu, 12 May 2022 14:28:36 -0700 (PDT) Received: by mail-pl1-x62d.google.com with SMTP id j14so6138519plx.3 for ; Thu, 12 May 2022 14:28:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=R6YC55yvG1FoH60PApU4i4PtJV15NOJHIrl/EzB9RvU=; b=EX8VKkwfjev2j5YSo3yCej/V3g0Z56GYXOiRkVjySictjbuLIcPvcTAV1BAO/M1qV2 YMF4swUgFUjejwYO4JKPo97KAqm1UBFmrptm8UEtj68DTCjCOJcCm2vJzHGcB0UeexyN xAD2jV+cl/pAtiqIeUvKLJA22IbQvd8AYTeoMpoLnx1eZSD9A/jsdFnkxjDMnqQybVV5 wQlI+t2aPKKDKDsS4loHfWc9dCez3/cQ1tgXaoMiATenEW646owbxfBsm0nKv0nZrt4I SY+hLJhNLobxyXwicT9FyZN+kRxFT1pRsknqiVinPX/m9Dk5ofaP+oSy1YldYfoMI4dc Vq5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=R6YC55yvG1FoH60PApU4i4PtJV15NOJHIrl/EzB9RvU=; b=VJPE6me8SOuSo+sbHiEtYDoNsmh6V6RZ9XhtvikdiuFT0h8imAkBcdvmy2kiOEdg56 wEdLIoyDdZp8zuuAu57m9dzTju892X7LhYtMMg5LJZiQnulcasvw4vAc51fv87roEFyI coMv1SORbi+JI8rpSY8gYXU0M2lHmjBulsHaFxNohP3t805eo+oqXNGuD8BHDbW6W2fy QwLGQcQLHnSk/50ziFNUjqAgGdvT5a0fmCismyQXVs4hZi/a3H81Xqg06bLvAkrzZXdp B9HsprTjRx5lz0S804guFd8c7WOlofUaJ3M5nO+6Sf35l+1t8loVKVA+JpeyeXhGaBQ7 rBaw== X-Gm-Message-State: AOAM531fTWFZzc3iIWAxKCB2mSoLwoSd5m2F3Jqpg4oE5NXRsRneR8Y3 PZy2FxWxb4IwxHVzCSJ1Dzc= X-Google-Smtp-Source: ABdhPJzflqt7XF77Vi0vGbtdGPfa5/CkOFO7qXYdLdA+/QGte6urDw2JwWFvuusZQShc0VmJ+EK5hw== X-Received: by 2002:a17:902:d707:b0:15f:42a:bc62 with SMTP id w7-20020a170902d70700b0015f042abc62mr1765693ply.98.1652390915459; Thu, 12 May 2022 14:28:35 -0700 (PDT) Received: from google.com ([2620:15c:211:201:872f:bbca:8e23:fae5]) by smtp.gmail.com with ESMTPSA id x12-20020a62860c000000b0050dc7628198sm265396pfd.114.2022.05.12.14.28.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 May 2022 14:28:35 -0700 (PDT) Sender: Minchan Kim Date: Thu, 12 May 2022 14:28:33 -0700 From: Minchan Kim To: Andrew Morton Cc: mm-commits@vger.kernel.org, paulmck@kernel.org, jhubbard@nvidia.com, david@redhat.com Subject: Re: + mm-fix-is_pinnable_page-against-on-cma-page-v5.patch added to mm-unstable branch Message-ID: References: <20220512204506.423D0C3411F@smtp.kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220512204506.423D0C3411F@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org On Thu, May 12, 2022 at 01:45:05PM -0700, Andrew Morton wrote: > > The patch titled > Subject: mm-fix-is_pinnable_page-against-on-cma-page-v5 > has been added to the -mm mm-unstable branch. Its filename is > mm-fix-is_pinnable_page-against-on-cma-page-v5.patch > > This patch will shortly appear at > https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-is_pinnable_page-against-on-cma-page-v5.patch > > This patch will later appear in the mm-unstable branch at > git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's > > *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** > > The -mm tree is included into linux-next via the mm-everything > branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > and is updated there every 2-3 working days > > ------------------------------------------------------ > From: Minchan Kim > Subject: mm-fix-is_pinnable_page-against-on-cma-page-v5 > > * clarification why we need READ_ONCE - Paul > * Add a comment about READ_ONCE - John > > Link: https://lkml.kernel.org/r/20220512204143.3961150-1-minchan@kernel.org > Signed-off-by: Minchan Kim > Cc: "Paul E . McKenney" > Cc: John Hubbard > Cc: David Hildenbrand > Signed-off-by: Andrew Morton > --- > > include/linux/mm.h | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > --- a/include/linux/mm.h~mm-fix-is_pinnable_page-against-on-cma-page-v5 > +++ a/include/linux/mm.h > @@ -1627,13 +1627,14 @@ static inline bool is_pinnable_page(stru > { > #ifdef CONFIG_CMA > /* > - * use volatile to use local variable mt instead of > - * refetching mt value. > + * Defend against future compiler LTO features, or code refactoring > + * that inlines the above function, by forcing a single read. Because, > + * this routine races with set_pageblock_migratetype(), and we want to > + * avoid reading zero, when actually one or the other flags was set. > */ > - int __mt = get_pageblock_migratetype(page); It makes build failure. Could you pick this up instead? https://lore.kernel.org/all/Yn10GkInyZNtqASa@google.com/ Sorry for confusing.