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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 83116C433E0 for ; Thu, 14 Jan 2021 20:10:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B5562310F for ; Thu, 14 Jan 2021 20:10:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730427AbhANUKl (ORCPT ); Thu, 14 Jan 2021 15:10:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729029AbhANUKl (ORCPT ); Thu, 14 Jan 2021 15:10:41 -0500 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D969C061575 for ; Thu, 14 Jan 2021 12:09:59 -0800 (PST) Received: by mail-pf1-x435.google.com with SMTP id a188so4008064pfa.11 for ; Thu, 14 Jan 2021 12:09:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=iB3Jw2esdANcXXH44eCvOPFepBca1nOJGZGOnewNohA=; b=lcbZ3BC5P4onmRMYQ9hVh1BhepJnL5kj7yeaJnlqQJci2AhhD1uTyOtCSGG7iYVnH9 zbJtF1PW43ulgDUYMEtMSkSXlBmPDuw0wXuSjZqlD8oZvPfetlNRcYRkNokRTsW3YJAC fWkpDS4G9qlMGD4taq4KMbrtifDbnv35KGEHA1GboksETpRQZHyF8b+sJ89+PEhudn8U SLQeGGdall+yZDICyOE3k6fGcJV8IXsQzxJZna0mPNqa7Qz8QdBmtbH6rohR8YAiafdJ cvVM80mIC64CxX6Dx2JKBcNVWLRmuqrqo5zghfxmRsnEUOll/H56kCb4Zk649Q+bHkeO Eaxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=iB3Jw2esdANcXXH44eCvOPFepBca1nOJGZGOnewNohA=; b=dCTgq5AivwgbjXizw4SYFdd/rmeGpCjTYBRzCCSjH57JRDL+vaWagqKOYjL0+17cDV LMOrKV3I2Jzr9VarYtB2MuJQQvQtsEo3H/a+kq5O2C78jhn6VY49gucicgDJsOozEj1j phQLQ1xSNobcY7MWgZUw2ZF1tGFj6jchQHD7avlg73maGYT7MjXxX+fH6XyjPTZzYnCb TDQ+fm1xFabK+UnIBH2uXea3YI+WuUWltdEvq4y4txFOe4+7EoMDCkL566+7Ose07ofE WDeI+elnd/KOgWSaZom9BVf3QP6WqSWcRAwwyA+vcOLYmGV8jFgg1qxmCjyL6ukptfaY vO8w== X-Gm-Message-State: AOAM530I/GgUvykP485mtD9P2BzELlZOoti0CkeyBnCzJ0XvTjk8ETbG gVea4JxgJy2pirGVRMPcTmtN7+tBNPRUoOFiNgPGOV5xGGO+Pg== X-Google-Smtp-Source: ABdhPJxdMZ11aeWYCth9RA14e3mnlFGCx9jVnSpd7hRCxYaZPBNfFDyacpfxrLMLEc0a6oFlcupomXmnJU7N7G73aak= X-Received: by 2002:a63:1142:: with SMTP id 2mr9162380pgr.263.1610654998210; Thu, 14 Jan 2021 12:09:58 -0800 (PST) MIME-Version: 1.0 References: <20210114175934.13070-1-will@kernel.org> <20210114175934.13070-5-will@kernel.org> <20210114190021.GB13135@willie-the-truck> <20210114194129.GA13314@willie-the-truck> In-Reply-To: <20210114194129.GA13314@willie-the-truck> From: Nick Desaulniers Date: Thu, 14 Jan 2021 12:09:47 -0800 Message-ID: Subject: Re: [RFC PATCH 4/8] mm: Separate fault info out of 'struct vm_fault' To: Will Deacon Cc: Linus Torvalds , Linux Kernel Mailing List , Linux-MM , Linux ARM , Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , "Kirill A . Shutemov" , Vinayak Menon , Hugh Dickins , Android Kernel Team Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 14, 2021 at 11:41 AM Will Deacon wrote: > > On Thu, Jan 14, 2021 at 11:09:01AM -0800, Linus Torvalds wrote: > > On Thu, Jan 14, 2021 at 11:00 AM Will Deacon wrote: > > > > > > I tried that initially, but I found that I had to make all of the > > > members const to get it to work, at which point the anonymous struct > > > wasn't really adding anything. Did I just botch the syntax? > > > > I'm not sure what you tried. But this stupid test-case sure works for m= e: > > > > struct hello { > > const struct { > > unsigned long address; > > }; > > unsigned int flags; > > }; > > > > extern int fn(struct hello *); > > > > int test(void) > > { > > struct hello a =3D { > > .address =3D 1, > > }; > > a.flags =3D 0; > > return fn(&a); > > } > > > > and because "address" is in that unnamed constant struct, you can only > > set it within that initializer, and cannot do > > > > a.address =3D 0; > > > > without an error (the way you _can_ do "a.flags =3D 0"). > > > > I don't see naming the struct making a difference - apart from forcing > > that big rename patch, of course. > > > > But maybe we're talking about different issues? > > Urgh... > > We _are_ both on the same page, and your reply above had me thinking I've > lost the plot, so I went back to the start. Check out v5.11-rc3 and apply > this patch: > > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ecdf8a8cd6ae..1eb950865450 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -514,11 +514,14 @@ static inline bool fault_flag_allow_retry_first(uns= igned int flags) > * pgoff should be used in favour of virtual_address, if possible. > */ > struct vm_fault { > - struct vm_area_struct *vma; /* Target VMA */ > + const struct { > + struct vm_area_struct *vma; /* Target VMA */ > + gfp_t gfp_mask; /* gfp mask to be used fo= r allocations */ > + pgoff_t pgoff; /* Logical page offset ba= sed on vma */ > + unsigned long address; /* Faulting virtual addre= ss */ > + }; > + > unsigned int flags; /* FAULT_FLAG_xxx flags */ > - gfp_t gfp_mask; /* gfp mask to be used for alloca= tions */ > - pgoff_t pgoff; /* Logical page offset based on v= ma */ > - unsigned long address; /* Faulting virtual address */ > pmd_t *pmd; /* Pointer to pmd entry matching > * the 'address' */ > pud_t *pud; /* Pointer to pud entry matching > > > Sure enough, an arm64 defconfig builds perfectly alright with that change= , > but it really shouldn't. I'm using clang 11.0.5, so I had another go with > GCC 9.2.1 and bang: > > mm/filemap.c: In function =E2=80=98filemap_map_pages=E2=80=99: > mm/filemap.c:2963:16: error: assignment of member =E2=80=98address=E2=80= =99 in read-only object > 2963 | vmf->address +=3D (xas.xa_index - last_pgoff) << PAGE_SHIFT; > | ^~ > make[1]: *** [scripts/Makefile.build:279: mm/filemap.o] Error 1 > make[1]: *** Waiting for unfinished jobs.... > make: *** [Makefile:1805: mm] Error 2 > make: *** Waiting for unfinished jobs.... > > Nick -- any clue what's happening here? We would like that const anonymou= s > struct to behave like a const struct member, as the alternative (naming t= he > thing) results in a lot of refactoring churn. Weird, looks like a bug to me in Clang, filed https://bugs.llvm.org/show_bug.cgi?id=3D48755. --=20 Thanks, ~Nick Desaulniers 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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL 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 1FB69C433E0 for ; Thu, 14 Jan 2021 20:10:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AA90323117 for ; Thu, 14 Jan 2021 20:10:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AA90323117 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AA60E8D0120; Thu, 14 Jan 2021 15:10:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A562E8D00F0; Thu, 14 Jan 2021 15:10:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 993BA8D0120; Thu, 14 Jan 2021 15:10:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0055.hostedemail.com [216.40.44.55]) by kanga.kvack.org (Postfix) with ESMTP id 8644D8D00F0 for ; Thu, 14 Jan 2021 15:10:00 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 45A28180AD807 for ; Thu, 14 Jan 2021 20:10:00 +0000 (UTC) X-FDA: 77705471760.21.comb66_0a1110427529 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin21.hostedemail.com (Postfix) with ESMTP id 26E1E18045A44 for ; Thu, 14 Jan 2021 20:10:00 +0000 (UTC) X-HE-Tag: comb66_0a1110427529 X-Filterd-Recvd-Size: 7261 Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Thu, 14 Jan 2021 20:09:59 +0000 (UTC) Received: by mail-pf1-f182.google.com with SMTP id m6so4031894pfk.1 for ; Thu, 14 Jan 2021 12:09:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=iB3Jw2esdANcXXH44eCvOPFepBca1nOJGZGOnewNohA=; b=lcbZ3BC5P4onmRMYQ9hVh1BhepJnL5kj7yeaJnlqQJci2AhhD1uTyOtCSGG7iYVnH9 zbJtF1PW43ulgDUYMEtMSkSXlBmPDuw0wXuSjZqlD8oZvPfetlNRcYRkNokRTsW3YJAC fWkpDS4G9qlMGD4taq4KMbrtifDbnv35KGEHA1GboksETpRQZHyF8b+sJ89+PEhudn8U SLQeGGdall+yZDICyOE3k6fGcJV8IXsQzxJZna0mPNqa7Qz8QdBmtbH6rohR8YAiafdJ cvVM80mIC64CxX6Dx2JKBcNVWLRmuqrqo5zghfxmRsnEUOll/H56kCb4Zk649Q+bHkeO Eaxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=iB3Jw2esdANcXXH44eCvOPFepBca1nOJGZGOnewNohA=; b=G7Zdd8twRao2sJdUSaYyWU2IumR+Up5cHeyccPdOwn3DaQMY4pbH8GZI0J20StHfTv IeujSn1enlixRkx75UqA8Y3tiele/YvDMxx+DQoKL6uezB6UYm6r3RoQMyIuto4dWUfG X1CnEfMLFtn1ssRQcure9SRlJwFkMer5v3jiZvjLBYkfMcIZbLYpgaj/rToMSfn0/55R iGxmxpa8qnK7ekKlcemkBzprZwk7XEzyB3AVQ/1RT3hVtIp9UhYPQBgKCPvzYW1h/1QW 6NGDa2Yif9kb/1AoE54xywhGS+UiHyrzUlCTZUhOJgzaHKphMHglC1Ygc2bDSa4UPRvp I+fQ== X-Gm-Message-State: AOAM533Ttbe15pe08FklStiVm2TySDbZ0X7FEYYy57KxJVu/lJHjyEA8 qyvjoPQFcW3KrwBmUP1iOtcOiF8YCPrnnFBCOdaAoQ== X-Google-Smtp-Source: ABdhPJxdMZ11aeWYCth9RA14e3mnlFGCx9jVnSpd7hRCxYaZPBNfFDyacpfxrLMLEc0a6oFlcupomXmnJU7N7G73aak= X-Received: by 2002:a63:1142:: with SMTP id 2mr9162380pgr.263.1610654998210; Thu, 14 Jan 2021 12:09:58 -0800 (PST) MIME-Version: 1.0 References: <20210114175934.13070-1-will@kernel.org> <20210114175934.13070-5-will@kernel.org> <20210114190021.GB13135@willie-the-truck> <20210114194129.GA13314@willie-the-truck> In-Reply-To: <20210114194129.GA13314@willie-the-truck> From: Nick Desaulniers Date: Thu, 14 Jan 2021 12:09:47 -0800 Message-ID: Subject: Re: [RFC PATCH 4/8] mm: Separate fault info out of 'struct vm_fault' To: Will Deacon Cc: Linus Torvalds , Linux Kernel Mailing List , Linux-MM , Linux ARM , Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , "Kirill A . Shutemov" , Vinayak Menon , Hugh Dickins , Android Kernel Team Content-Type: text/plain; charset="UTF-8" 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 Thu, Jan 14, 2021 at 11:41 AM Will Deacon wrote: > > On Thu, Jan 14, 2021 at 11:09:01AM -0800, Linus Torvalds wrote: > > On Thu, Jan 14, 2021 at 11:00 AM Will Deacon wrote: > > > > > > I tried that initially, but I found that I had to make all of the > > > members const to get it to work, at which point the anonymous struct > > > wasn't really adding anything. Did I just botch the syntax? > > > > I'm not sure what you tried. But this stupid test-case sure works for m= e: > > > > struct hello { > > const struct { > > unsigned long address; > > }; > > unsigned int flags; > > }; > > > > extern int fn(struct hello *); > > > > int test(void) > > { > > struct hello a =3D { > > .address =3D 1, > > }; > > a.flags =3D 0; > > return fn(&a); > > } > > > > and because "address" is in that unnamed constant struct, you can only > > set it within that initializer, and cannot do > > > > a.address =3D 0; > > > > without an error (the way you _can_ do "a.flags =3D 0"). > > > > I don't see naming the struct making a difference - apart from forcing > > that big rename patch, of course. > > > > But maybe we're talking about different issues? > > Urgh... > > We _are_ both on the same page, and your reply above had me thinking I've > lost the plot, so I went back to the start. Check out v5.11-rc3 and apply > this patch: > > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ecdf8a8cd6ae..1eb950865450 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -514,11 +514,14 @@ static inline bool fault_flag_allow_retry_first(uns= igned int flags) > * pgoff should be used in favour of virtual_address, if possible. > */ > struct vm_fault { > - struct vm_area_struct *vma; /* Target VMA */ > + const struct { > + struct vm_area_struct *vma; /* Target VMA */ > + gfp_t gfp_mask; /* gfp mask to be used fo= r allocations */ > + pgoff_t pgoff; /* Logical page offset ba= sed on vma */ > + unsigned long address; /* Faulting virtual addre= ss */ > + }; > + > unsigned int flags; /* FAULT_FLAG_xxx flags */ > - gfp_t gfp_mask; /* gfp mask to be used for alloca= tions */ > - pgoff_t pgoff; /* Logical page offset based on v= ma */ > - unsigned long address; /* Faulting virtual address */ > pmd_t *pmd; /* Pointer to pmd entry matching > * the 'address' */ > pud_t *pud; /* Pointer to pud entry matching > > > Sure enough, an arm64 defconfig builds perfectly alright with that change= , > but it really shouldn't. I'm using clang 11.0.5, so I had another go with > GCC 9.2.1 and bang: > > mm/filemap.c: In function =E2=80=98filemap_map_pages=E2=80=99: > mm/filemap.c:2963:16: error: assignment of member =E2=80=98address=E2=80= =99 in read-only object > 2963 | vmf->address +=3D (xas.xa_index - last_pgoff) << PAGE_SHIFT; > | ^~ > make[1]: *** [scripts/Makefile.build:279: mm/filemap.o] Error 1 > make[1]: *** Waiting for unfinished jobs.... > make: *** [Makefile:1805: mm] Error 2 > make: *** Waiting for unfinished jobs.... > > Nick -- any clue what's happening here? We would like that const anonymou= s > struct to behave like a const struct member, as the alternative (naming t= he > thing) results in a lot of refactoring churn. Weird, looks like a bug to me in Clang, filed https://bugs.llvm.org/show_bug.cgi?id=3D48755. --=20 Thanks, ~Nick Desaulniers 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=-9.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 207D9C433E0 for ; Thu, 14 Jan 2021 20:11:29 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CBC9F2310F for ; Thu, 14 Jan 2021 20:11:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CBC9F2310F Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=y7yyGSxCtudrswJnGXMEnDJyUtZsIpLLKk+/R447Nd0=; b=y9qDvkuEBOYIGaMQTb6Vphxy1 Z7jwwoN6qXuwsXsXoeSBwnmv/rLOhmrXqI7hVnz3s5IZ3bm5VYtPeK5RPXgezhTQ9QLdmBYT4/UrR j7jQaMH/Mnwda79X42V9U96E6pjFpMoPSPmYH2GaKlJq3APSWsLl5YwtMuucmlof66Pf8O+dSQvRD wLkwLJM1z6LJfrQc0U52gVGxTS2EKxx3jjEzuahj1/nv9lLKrhKHmy9caVIOQ6r8sb6zdCBUE98Pf oaZpa1ZUHm96a496pIFwu2tHAwsurXR8Cm4mrNaZ9JeZOm+h73JlqI8QZHNrNsihS8V3149FXZ2df sT4cqCP5g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l08wX-0003AW-IU; Thu, 14 Jan 2021 20:10:05 +0000 Received: from mail-pf1-x429.google.com ([2607:f8b0:4864:20::429]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l08wV-00039Q-29 for linux-arm-kernel@lists.infradead.org; Thu, 14 Jan 2021 20:10:04 +0000 Received: by mail-pf1-x429.google.com with SMTP id b3so4034323pft.3 for ; Thu, 14 Jan 2021 12:10:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=iB3Jw2esdANcXXH44eCvOPFepBca1nOJGZGOnewNohA=; b=lcbZ3BC5P4onmRMYQ9hVh1BhepJnL5kj7yeaJnlqQJci2AhhD1uTyOtCSGG7iYVnH9 zbJtF1PW43ulgDUYMEtMSkSXlBmPDuw0wXuSjZqlD8oZvPfetlNRcYRkNokRTsW3YJAC fWkpDS4G9qlMGD4taq4KMbrtifDbnv35KGEHA1GboksETpRQZHyF8b+sJ89+PEhudn8U SLQeGGdall+yZDICyOE3k6fGcJV8IXsQzxJZna0mPNqa7Qz8QdBmtbH6rohR8YAiafdJ cvVM80mIC64CxX6Dx2JKBcNVWLRmuqrqo5zghfxmRsnEUOll/H56kCb4Zk649Q+bHkeO Eaxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=iB3Jw2esdANcXXH44eCvOPFepBca1nOJGZGOnewNohA=; b=QLU5xv19j7g8KIiPgTB04I+9GJqfrHkY3rUeqJwaA4+CtwnpwubnLUOBe1WBnynKuB cFo4LIQEwbT4UOZmv22usR4aXDgRrOh1rFp3IUL1dP72eUaed4ibRRzRSgtdk3l/08E5 KxQkxYVBUh2mKEMCY/roDiNTISukyHndN8qyQOP6+Pi01HRXZn++MQhXtoA+5v3NOHcF OMC4Mte5rRxtICvqJ1yffJ0vS1IDb+7JFniZxb5OAjILXMpFk+6DYPsFDaeh2EqwP4G6 Dc2f9i9PV9v2cuIDnlGzp2Ankx1NtdL7Df/LQi+KI2mvX1PSqF3JwVTGNCjYBZkoY6R9 fRGw== X-Gm-Message-State: AOAM530mioqLwedkrbcuLdEobWN1lP0x870ZkK1pB142X/R95FrGRNgb /q01DH04DygyaxP3V2GjY511U+/QcbeK8a1vvrbKwA== X-Google-Smtp-Source: ABdhPJxdMZ11aeWYCth9RA14e3mnlFGCx9jVnSpd7hRCxYaZPBNfFDyacpfxrLMLEc0a6oFlcupomXmnJU7N7G73aak= X-Received: by 2002:a63:1142:: with SMTP id 2mr9162380pgr.263.1610654998210; Thu, 14 Jan 2021 12:09:58 -0800 (PST) MIME-Version: 1.0 References: <20210114175934.13070-1-will@kernel.org> <20210114175934.13070-5-will@kernel.org> <20210114190021.GB13135@willie-the-truck> <20210114194129.GA13314@willie-the-truck> In-Reply-To: <20210114194129.GA13314@willie-the-truck> From: Nick Desaulniers Date: Thu, 14 Jan 2021 12:09:47 -0800 Message-ID: Subject: Re: [RFC PATCH 4/8] mm: Separate fault info out of 'struct vm_fault' To: Will Deacon X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210114_151003_410631_0B5AB457 X-CRM114-Status: GOOD ( 31.74 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Android Kernel Team , Jan Kara , Minchan Kim , Catalin Marinas , Hugh Dickins , Linux Kernel Mailing List , Linux-MM , Vinayak Menon , "Kirill A . Shutemov" , Andrew Morton , Linus Torvalds , Linux ARM Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gVGh1LCBKYW4gMTQsIDIwMjEgYXQgMTE6NDEgQU0gV2lsbCBEZWFjb24gPHdpbGxAa2VybmVs Lm9yZz4gd3JvdGU6Cj4KPiBPbiBUaHUsIEphbiAxNCwgMjAyMSBhdCAxMTowOTowMUFNIC0wODAw LCBMaW51cyBUb3J2YWxkcyB3cm90ZToKPiA+IE9uIFRodSwgSmFuIDE0LCAyMDIxIGF0IDExOjAw IEFNIFdpbGwgRGVhY29uIDx3aWxsQGtlcm5lbC5vcmc+IHdyb3RlOgo+ID4gPgo+ID4gPiBJIHRy aWVkIHRoYXQgaW5pdGlhbGx5LCBidXQgSSBmb3VuZCB0aGF0IEkgaGFkIHRvIG1ha2UgYWxsIG9m IHRoZQo+ID4gPiBtZW1iZXJzIGNvbnN0IHRvIGdldCBpdCB0byB3b3JrLCBhdCB3aGljaCBwb2lu dCB0aGUgYW5vbnltb3VzIHN0cnVjdAo+ID4gPiB3YXNuJ3QgcmVhbGx5IGFkZGluZyBhbnl0aGlu Zy4gRGlkIEkganVzdCBib3RjaCB0aGUgc3ludGF4Pwo+ID4KPiA+IEknbSBub3Qgc3VyZSB3aGF0 IHlvdSB0cmllZC4gQnV0IHRoaXMgc3R1cGlkIHRlc3QtY2FzZSBzdXJlIHdvcmtzIGZvciBtZToK PiA+Cj4gPiAgICAgc3RydWN0IGhlbGxvIHsKPiA+ICAgICAgICAgY29uc3Qgc3RydWN0IHsKPiA+ ICAgICAgICAgICAgICAgICB1bnNpZ25lZCBsb25nIGFkZHJlc3M7Cj4gPiAgICAgICAgIH07Cj4g PiAgICAgICAgIHVuc2lnbmVkIGludCBmbGFnczsKPiA+ICAgICB9Owo+ID4KPiA+ICAgICBleHRl cm4gaW50IGZuKHN0cnVjdCBoZWxsbyAqKTsKPiA+Cj4gPiAgICAgaW50IHRlc3Qodm9pZCkKPiA+ ICAgICB7Cj4gPiAgICAgICAgIHN0cnVjdCBoZWxsbyBhID0gewo+ID4gICAgICAgICAgICAgICAg IC5hZGRyZXNzID0gMSwKPiA+ICAgICAgICAgfTsKPiA+ICAgICAgICAgYS5mbGFncyA9IDA7Cj4g PiAgICAgICAgIHJldHVybiBmbigmYSk7Cj4gPiAgICAgfQo+ID4KPiA+IGFuZCBiZWNhdXNlICJh ZGRyZXNzIiBpcyBpbiB0aGF0IHVubmFtZWQgY29uc3RhbnQgc3RydWN0LCB5b3UgY2FuIG9ubHkK PiA+IHNldCBpdCB3aXRoaW4gdGhhdCBpbml0aWFsaXplciwgYW5kIGNhbm5vdCBkbwo+ID4KPiA+ ICAgICAgICAgYS5hZGRyZXNzID0gMDsKPiA+Cj4gPiB3aXRob3V0IGFuIGVycm9yICh0aGUgd2F5 IHlvdSBfY2FuXyBkbyAiYS5mbGFncyA9IDAiKS4KPiA+Cj4gPiBJIGRvbid0IHNlZSBuYW1pbmcg dGhlIHN0cnVjdCBtYWtpbmcgYSBkaWZmZXJlbmNlIC0gYXBhcnQgZnJvbSBmb3JjaW5nCj4gPiB0 aGF0IGJpZyByZW5hbWUgcGF0Y2gsIG9mIGNvdXJzZS4KPiA+Cj4gPiBCdXQgbWF5YmUgd2UncmUg dGFsa2luZyBhYm91dCBkaWZmZXJlbnQgaXNzdWVzPwo+Cj4gVXJnaC4uLgo+Cj4gV2UgX2FyZV8g Ym90aCBvbiB0aGUgc2FtZSBwYWdlLCBhbmQgeW91ciByZXBseSBhYm92ZSBoYWQgbWUgdGhpbmtp bmcgSSd2ZQo+IGxvc3QgdGhlIHBsb3QsIHNvIEkgd2VudCBiYWNrIHRvIHRoZSBzdGFydC4gQ2hl Y2sgb3V0IHY1LjExLXJjMyBhbmQgYXBwbHkKPiB0aGlzIHBhdGNoOgo+Cj4KPiBkaWZmIC0tZ2l0 IGEvaW5jbHVkZS9saW51eC9tbS5oIGIvaW5jbHVkZS9saW51eC9tbS5oCj4gaW5kZXggZWNkZjhh OGNkNmFlLi4xZWI5NTA4NjU0NTAgMTAwNjQ0Cj4gLS0tIGEvaW5jbHVkZS9saW51eC9tbS5oCj4g KysrIGIvaW5jbHVkZS9saW51eC9tbS5oCj4gQEAgLTUxNCwxMSArNTE0LDE0IEBAIHN0YXRpYyBp bmxpbmUgYm9vbCBmYXVsdF9mbGFnX2FsbG93X3JldHJ5X2ZpcnN0KHVuc2lnbmVkIGludCBmbGFn cykKPiAgICogcGdvZmYgc2hvdWxkIGJlIHVzZWQgaW4gZmF2b3VyIG9mIHZpcnR1YWxfYWRkcmVz cywgaWYgcG9zc2libGUuCj4gICAqLwo+ICBzdHJ1Y3Qgdm1fZmF1bHQgewo+IC0gICAgICAgc3Ry dWN0IHZtX2FyZWFfc3RydWN0ICp2bWE7ICAgICAvKiBUYXJnZXQgVk1BICovCj4gKyAgICAgICBj b25zdCBzdHJ1Y3Qgewo+ICsgICAgICAgICAgICAgICBzdHJ1Y3Qgdm1fYXJlYV9zdHJ1Y3QgKnZt YTsgICAgIC8qIFRhcmdldCBWTUEgKi8KPiArICAgICAgICAgICAgICAgZ2ZwX3QgZ2ZwX21hc2s7 ICAgICAgICAgICAgICAgICAvKiBnZnAgbWFzayB0byBiZSB1c2VkIGZvciBhbGxvY2F0aW9ucyAq Lwo+ICsgICAgICAgICAgICAgICBwZ29mZl90IHBnb2ZmOyAgICAgICAgICAgICAgICAgIC8qIExv Z2ljYWwgcGFnZSBvZmZzZXQgYmFzZWQgb24gdm1hICovCj4gKyAgICAgICAgICAgICAgIHVuc2ln bmVkIGxvbmcgYWRkcmVzczsgICAgICAgICAgLyogRmF1bHRpbmcgdmlydHVhbCBhZGRyZXNzICov Cj4gKyAgICAgICB9Owo+ICsKPiAgICAgICAgIHVuc2lnbmVkIGludCBmbGFnczsgICAgICAgICAg ICAgLyogRkFVTFRfRkxBR194eHggZmxhZ3MgKi8KPiAtICAgICAgIGdmcF90IGdmcF9tYXNrOyAg ICAgICAgICAgICAgICAgLyogZ2ZwIG1hc2sgdG8gYmUgdXNlZCBmb3IgYWxsb2NhdGlvbnMgKi8K PiAtICAgICAgIHBnb2ZmX3QgcGdvZmY7ICAgICAgICAgICAgICAgICAgLyogTG9naWNhbCBwYWdl IG9mZnNldCBiYXNlZCBvbiB2bWEgKi8KPiAtICAgICAgIHVuc2lnbmVkIGxvbmcgYWRkcmVzczsg ICAgICAgICAgLyogRmF1bHRpbmcgdmlydHVhbCBhZGRyZXNzICovCj4gICAgICAgICBwbWRfdCAq cG1kOyAgICAgICAgICAgICAgICAgICAgIC8qIFBvaW50ZXIgdG8gcG1kIGVudHJ5IG1hdGNoaW5n Cj4gICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAqIHRoZSAnYWRkcmVz cycgKi8KPiAgICAgICAgIHB1ZF90ICpwdWQ7ICAgICAgICAgICAgICAgICAgICAgLyogUG9pbnRl ciB0byBwdWQgZW50cnkgbWF0Y2hpbmcKPgo+Cj4gU3VyZSBlbm91Z2gsIGFuIGFybTY0IGRlZmNv bmZpZyBidWlsZHMgcGVyZmVjdGx5IGFscmlnaHQgd2l0aCB0aGF0IGNoYW5nZSwKPiBidXQgaXQg cmVhbGx5IHNob3VsZG4ndC4gSSdtIHVzaW5nIGNsYW5nIDExLjAuNSwgc28gSSBoYWQgYW5vdGhl ciBnbyB3aXRoCj4gR0NDIDkuMi4xIGFuZCBiYW5nOgo+Cj4gbW0vZmlsZW1hcC5jOiBJbiBmdW5j dGlvbiDigJhmaWxlbWFwX21hcF9wYWdlc+KAmToKPiBtbS9maWxlbWFwLmM6Mjk2MzoxNjogZXJy b3I6IGFzc2lnbm1lbnQgb2YgbWVtYmVyIOKAmGFkZHJlc3PigJkgaW4gcmVhZC1vbmx5IG9iamVj dAo+ICAyOTYzIHwgICB2bWYtPmFkZHJlc3MgKz0gKHhhcy54YV9pbmRleCAtIGxhc3RfcGdvZmYp IDw8IFBBR0VfU0hJRlQ7Cj4gICAgICAgfCAgICAgICAgICAgICAgICBefgo+IG1ha2VbMV06ICoq KiBbc2NyaXB0cy9NYWtlZmlsZS5idWlsZDoyNzk6IG1tL2ZpbGVtYXAub10gRXJyb3IgMQo+IG1h a2VbMV06ICoqKiBXYWl0aW5nIGZvciB1bmZpbmlzaGVkIGpvYnMuLi4uCj4gbWFrZTogKioqIFtN YWtlZmlsZToxODA1OiBtbV0gRXJyb3IgMgo+IG1ha2U6ICoqKiBXYWl0aW5nIGZvciB1bmZpbmlz aGVkIGpvYnMuLi4uCj4KPiBOaWNrIC0tIGFueSBjbHVlIHdoYXQncyBoYXBwZW5pbmcgaGVyZT8g V2Ugd291bGQgbGlrZSB0aGF0IGNvbnN0IGFub255bW91cwo+IHN0cnVjdCB0byBiZWhhdmUgbGlr ZSBhIGNvbnN0IHN0cnVjdCBtZW1iZXIsIGFzIHRoZSBhbHRlcm5hdGl2ZSAobmFtaW5nIHRoZQo+ IHRoaW5nKSByZXN1bHRzIGluIGEgbG90IG9mIHJlZmFjdG9yaW5nIGNodXJuLgoKV2VpcmQsIGxv b2tzIGxpa2UgYSBidWcgdG8gbWUgaW4gQ2xhbmcsIGZpbGVkCmh0dHBzOi8vYnVncy5sbHZtLm9y Zy9zaG93X2J1Zy5jZ2k/aWQ9NDg3NTUuCi0tIApUaGFua3MsCn5OaWNrIERlc2F1bG5pZXJzCgpf X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1hcm0t a2VybmVsIG1haWxpbmcgbGlzdApsaW51eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcK aHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1hcm0ta2Vy bmVsCg==