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=-6.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 3140EC433E2 for ; Tue, 8 Sep 2020 04:43:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC42521532 for ; Tue, 8 Sep 2020 04:43:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728614AbgIHEnL (ORCPT ); Tue, 8 Sep 2020 00:43:11 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:64482 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728576AbgIHEnD (ORCPT ); Tue, 8 Sep 2020 00:43:03 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4Blsw04dynz9v07M; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id 1zRgiYU2XgXP; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4Blsw02Lphz9v07L; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 0E1EE8B775; Tue, 8 Sep 2020 06:42:57 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id IWq5rXD7F6WV; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id D80618B768; Tue, 8 Sep 2020 06:42:54 +0200 (CEST) Subject: Re: [RFC PATCH v2 0/3] mm/gup: fix gup_fast with dynamic page table folding To: Gerald Schaefer , Jason Gunthorpe , John Hubbard Cc: Peter Zijlstra , Dave Hansen , linux-mm , Paul Mackerras , linux-sparc , Alexander Gordeev , Claudio Imbrenda , Will Deacon , linux-arch , linux-s390 , Vasily Gorbik , Richard Weinberger , linux-x86 , Russell King , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Andrey Ryabinin , Heiko Carstens , Arnd Bergmann , Jeff Dike , linux-um , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm , linux-power , LKML , Andrew Morton , Linus Torvalds , Mike Rapoport References: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> From: Christophe Leroy Message-ID: <9f9acde7-c400-53b0-38ec-ad3e48de5371@csgroup.eu> Date: Tue, 8 Sep 2020 06:42:50 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 07/09/2020 à 20:00, Gerald Schaefer a écrit : > This is v2 of an RFC previously discussed here: > https://lore.kernel.org/lkml/20200828140314.8556-1-gerald.schaefer@linux.ibm.com/ > > Patch 1 is a fix for a regression in gup_fast on s390, after our conversion > to common gup_fast code. It will introduce special helper functions > pXd_addr_end_folded(), which have to be used in places where pagetable walk > is done w/o lock and with READ_ONCE, so currently only in gup_fast. > > Patch 2 is an attempt to make that more generic, i.e. change pXd_addr_end() > themselves by adding an extra pXd value parameter. That was suggested by > Jason during v1 discussion, because he is already thinking of some other > places where he might want to switch to the READ_ONCE logic for pagetable > walks. In general, that would be the cleanest / safest solution, but there > is some impact on other architectures and common code, hence the new and > greatly enlarged recipient list. > > Patch 3 is a "nice to have" add-on, which makes pXd_addr_end() inline > functions instead of #defines, so that we get some type checking for the > new pXd value parameter. > > Not sure about Fixes/stable tags for the generic solution. Only patch 1 > fixes a real bug on s390, and has Fixes/stable tags. Patches 2 + 3 might > still be nice to have in stable, to ease future backports, but I guess > "nice to have" does not really qualify for stable backports. If one day you have to backport a fix that requires patch 2 and/or 3, just mark it "depends-on:" and the patches will go in stable at the relevant time. Christophe From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christophe Leroy Date: Tue, 08 Sep 2020 04:42:50 +0000 Subject: Re: [RFC PATCH v2 0/3] mm/gup: fix gup_fast with dynamic page table folding Message-Id: <9f9acde7-c400-53b0-38ec-ad3e48de5371@csgroup.eu> List-Id: References: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> In-Reply-To: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Gerald Schaefer , Jason Gunthorpe , John Hubbard Cc: Peter Zijlstra , Dave Hansen , linux-mm , Paul Mackerras , linux-sparc , Alexander Gordeev , Claudio Imbrenda , Will Deacon , linux-arch , linux-s390 , Vasily Gorbik , Richard Weinberger , linux-x86 , Russell King , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Andrey Ryabinin , Heiko Carstens , Arnd Bergmann , Jeff Dike , linux-um , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm , linux-power , LKML , Andrew Morton , Linus Torvalds , Mike Rapoport Le 07/09/2020 à 20:00, Gerald Schaefer a écrit : > This is v2 of an RFC previously discussed here: > https://lore.kernel.org/lkml/20200828140314.8556-1-gerald.schaefer@linux.ibm.com/ > > Patch 1 is a fix for a regression in gup_fast on s390, after our conversion > to common gup_fast code. It will introduce special helper functions > pXd_addr_end_folded(), which have to be used in places where pagetable walk > is done w/o lock and with READ_ONCE, so currently only in gup_fast. > > Patch 2 is an attempt to make that more generic, i.e. change pXd_addr_end() > themselves by adding an extra pXd value parameter. That was suggested by > Jason during v1 discussion, because he is already thinking of some other > places where he might want to switch to the READ_ONCE logic for pagetable > walks. In general, that would be the cleanest / safest solution, but there > is some impact on other architectures and common code, hence the new and > greatly enlarged recipient list. > > Patch 3 is a "nice to have" add-on, which makes pXd_addr_end() inline > functions instead of #defines, so that we get some type checking for the > new pXd value parameter. > > Not sure about Fixes/stable tags for the generic solution. Only patch 1 > fixes a real bug on s390, and has Fixes/stable tags. Patches 2 + 3 might > still be nice to have in stable, to ease future backports, but I guess > "nice to have" does not really qualify for stable backports. If one day you have to backport a fix that requires patch 2 and/or 3, just mark it "depends-on:" and the patches will go in stable at the relevant time. Christophe 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=-6.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 596F3C2BBD0 for ; Tue, 8 Sep 2020 04:44:51 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 7FA8C21532 for ; Tue, 8 Sep 2020 04:44:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7FA8C21532 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4Blsy75nYTzDqCT for ; Tue, 8 Sep 2020 14:44:47 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4BlswC68DDzDqMn for ; Tue, 8 Sep 2020 14:43:03 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4Blsw04dynz9v07M; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id 1zRgiYU2XgXP; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4Blsw02Lphz9v07L; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 0E1EE8B775; Tue, 8 Sep 2020 06:42:57 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id IWq5rXD7F6WV; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id D80618B768; Tue, 8 Sep 2020 06:42:54 +0200 (CEST) Subject: Re: [RFC PATCH v2 0/3] mm/gup: fix gup_fast with dynamic page table folding To: Gerald Schaefer , Jason Gunthorpe , John Hubbard References: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> From: Christophe Leroy Message-ID: <9f9acde7-c400-53b0-38ec-ad3e48de5371@csgroup.eu> Date: Tue, 8 Sep 2020 06:42:50 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm , Paul Mackerras , linux-sparc , Alexander Gordeev , Claudio Imbrenda , Will Deacon , linux-arch , linux-s390 , Vasily Gorbik , Richard Weinberger , linux-x86 , Russell King , Christian Borntraeger , Ingo Molnar , Andrey Ryabinin , Jeff Dike , Arnd Bergmann , Heiko Carstens , linux-um , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm , Linus Torvalds , LKML , Andrew Morton , linux-power , Mike Rapoport Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Le 07/09/2020 à 20:00, Gerald Schaefer a écrit : > This is v2 of an RFC previously discussed here: > https://lore.kernel.org/lkml/20200828140314.8556-1-gerald.schaefer@linux.ibm.com/ > > Patch 1 is a fix for a regression in gup_fast on s390, after our conversion > to common gup_fast code. It will introduce special helper functions > pXd_addr_end_folded(), which have to be used in places where pagetable walk > is done w/o lock and with READ_ONCE, so currently only in gup_fast. > > Patch 2 is an attempt to make that more generic, i.e. change pXd_addr_end() > themselves by adding an extra pXd value parameter. That was suggested by > Jason during v1 discussion, because he is already thinking of some other > places where he might want to switch to the READ_ONCE logic for pagetable > walks. In general, that would be the cleanest / safest solution, but there > is some impact on other architectures and common code, hence the new and > greatly enlarged recipient list. > > Patch 3 is a "nice to have" add-on, which makes pXd_addr_end() inline > functions instead of #defines, so that we get some type checking for the > new pXd value parameter. > > Not sure about Fixes/stable tags for the generic solution. Only patch 1 > fixes a real bug on s390, and has Fixes/stable tags. Patches 2 + 3 might > still be nice to have in stable, to ease future backports, but I guess > "nice to have" does not really qualify for stable backports. If one day you have to backport a fix that requires patch 2 and/or 3, just mark it "depends-on:" and the patches will go in stable at the relevant time. Christophe 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=-6.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 7858FC43461 for ; Tue, 8 Sep 2020 04:44:42 +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 1673221532 for ; Tue, 8 Sep 2020 04:44:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="EjsgPNVG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1673221532 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu 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-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ngb6Cm308GBcTD91YEFYA7XTDam+sbnxaFxWdfkFB2Y=; b=EjsgPNVGVgiyg3Kx+9DE6Ctu2 hM7uOYCb8EF0rtxXcE/JMdwoaQf8yLlc23oisqD0MjO0u04l6BhkMbry/rDYUm+OFYenlRk6nPXrT dytNfC70VpnN1orP6a1iu66+LR6g+cL0QFqxkHHxjTHZwYuL+gpqDJRaqJrp4dlCvJu6JU7laFGX2 7xFYwJoorDFMH+vJZDJoweXI4hLrQy2KfZCHVzwRT0lfGLbm2Q67K17dAhOdTL9C4LfN89beyxfTF V0IrUQObE2hxOBN+WJWKwUQZ9nBkvocVU+GYH4N2yLB4nU8yp3eFckEKKMfBuPrpiaR232h33rqtv 9b2LAUPsA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kFVTJ-0001mJ-D0; Tue, 08 Sep 2020 04:43:09 +0000 Received: from pegase1.c-s.fr ([93.17.236.30]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kFVTD-0001kJ-Lc; Tue, 08 Sep 2020 04:43:05 +0000 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4Blsw04dynz9v07M; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id 1zRgiYU2XgXP; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4Blsw02Lphz9v07L; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 0E1EE8B775; Tue, 8 Sep 2020 06:42:57 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id IWq5rXD7F6WV; Tue, 8 Sep 2020 06:42:56 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id D80618B768; Tue, 8 Sep 2020 06:42:54 +0200 (CEST) Subject: Re: [RFC PATCH v2 0/3] mm/gup: fix gup_fast with dynamic page table folding To: Gerald Schaefer , Jason Gunthorpe , John Hubbard References: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> From: Christophe Leroy Message-ID: <9f9acde7-c400-53b0-38ec-ad3e48de5371@csgroup.eu> Date: Tue, 8 Sep 2020 06:42:50 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> Content-Language: fr X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200908_004304_149650_82B36428 X-CRM114-Status: GOOD ( 19.56 ) 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: Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm , Paul Mackerras , linux-sparc , Alexander Gordeev , Claudio Imbrenda , Will Deacon , linux-arch , linux-s390 , Vasily Gorbik , Richard Weinberger , linux-x86 , Russell King , Christian Borntraeger , Ingo Molnar , Andrey Ryabinin , Jeff Dike , Arnd Bergmann , Heiko Carstens , linux-um , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm , Linus Torvalds , LKML , Andrew Morton , linux-power , Mike Rapoport Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org CgpMZSAwNy8wOS8yMDIwIMOgIDIwOjAwLCBHZXJhbGQgU2NoYWVmZXIgYSDDqWNyaXTCoDoKPiBU aGlzIGlzIHYyIG9mIGFuIFJGQyBwcmV2aW91c2x5IGRpc2N1c3NlZCBoZXJlOgo+IGh0dHBzOi8v bG9yZS5rZXJuZWwub3JnL2xrbWwvMjAyMDA4MjgxNDAzMTQuODU1Ni0xLWdlcmFsZC5zY2hhZWZl ckBsaW51eC5pYm0uY29tLwo+IAo+IFBhdGNoIDEgaXMgYSBmaXggZm9yIGEgcmVncmVzc2lvbiBp biBndXBfZmFzdCBvbiBzMzkwLCBhZnRlciBvdXIgY29udmVyc2lvbgo+IHRvIGNvbW1vbiBndXBf ZmFzdCBjb2RlLiBJdCB3aWxsIGludHJvZHVjZSBzcGVjaWFsIGhlbHBlciBmdW5jdGlvbnMKPiBw WGRfYWRkcl9lbmRfZm9sZGVkKCksIHdoaWNoIGhhdmUgdG8gYmUgdXNlZCBpbiBwbGFjZXMgd2hl cmUgcGFnZXRhYmxlIHdhbGsKPiBpcyBkb25lIHcvbyBsb2NrIGFuZCB3aXRoIFJFQURfT05DRSwg c28gY3VycmVudGx5IG9ubHkgaW4gZ3VwX2Zhc3QuCj4gCj4gUGF0Y2ggMiBpcyBhbiBhdHRlbXB0 IHRvIG1ha2UgdGhhdCBtb3JlIGdlbmVyaWMsIGkuZS4gY2hhbmdlIHBYZF9hZGRyX2VuZCgpCj4g dGhlbXNlbHZlcyBieSBhZGRpbmcgYW4gZXh0cmEgcFhkIHZhbHVlIHBhcmFtZXRlci4gVGhhdCB3 YXMgc3VnZ2VzdGVkIGJ5Cj4gSmFzb24gZHVyaW5nIHYxIGRpc2N1c3Npb24sIGJlY2F1c2UgaGUg aXMgYWxyZWFkeSB0aGlua2luZyBvZiBzb21lIG90aGVyCj4gcGxhY2VzIHdoZXJlIGhlIG1pZ2h0 IHdhbnQgdG8gc3dpdGNoIHRvIHRoZSBSRUFEX09OQ0UgbG9naWMgZm9yIHBhZ2V0YWJsZQo+IHdh bGtzLiBJbiBnZW5lcmFsLCB0aGF0IHdvdWxkIGJlIHRoZSBjbGVhbmVzdCAvIHNhZmVzdCBzb2x1 dGlvbiwgYnV0IHRoZXJlCj4gaXMgc29tZSBpbXBhY3Qgb24gb3RoZXIgYXJjaGl0ZWN0dXJlcyBh bmQgY29tbW9uIGNvZGUsIGhlbmNlIHRoZSBuZXcgYW5kCj4gZ3JlYXRseSBlbmxhcmdlZCByZWNp cGllbnQgbGlzdC4KPiAKPiBQYXRjaCAzIGlzIGEgIm5pY2UgdG8gaGF2ZSIgYWRkLW9uLCB3aGlj aCBtYWtlcyBwWGRfYWRkcl9lbmQoKSBpbmxpbmUKPiBmdW5jdGlvbnMgaW5zdGVhZCBvZiAjZGVm aW5lcywgc28gdGhhdCB3ZSBnZXQgc29tZSB0eXBlIGNoZWNraW5nIGZvciB0aGUKPiBuZXcgcFhk IHZhbHVlIHBhcmFtZXRlci4KPiAKPiBOb3Qgc3VyZSBhYm91dCBGaXhlcy9zdGFibGUgdGFncyBm b3IgdGhlIGdlbmVyaWMgc29sdXRpb24uIE9ubHkgcGF0Y2ggMQo+IGZpeGVzIGEgcmVhbCBidWcg b24gczM5MCwgYW5kIGhhcyBGaXhlcy9zdGFibGUgdGFncy4gUGF0Y2hlcyAyICsgMyBtaWdodAo+ IHN0aWxsIGJlIG5pY2UgdG8gaGF2ZSBpbiBzdGFibGUsIHRvIGVhc2UgZnV0dXJlIGJhY2twb3J0 cywgYnV0IEkgZ3Vlc3MKPiAibmljZSB0byBoYXZlIiBkb2VzIG5vdCByZWFsbHkgcXVhbGlmeSBm b3Igc3RhYmxlIGJhY2twb3J0cy4KCklmIG9uZSBkYXkgeW91IGhhdmUgdG8gYmFja3BvcnQgYSBm aXggdGhhdCByZXF1aXJlcyBwYXRjaCAyIGFuZC9vciAzLCAKanVzdCBtYXJrIGl0ICJkZXBlbmRz LW9uOiIgYW5kIHRoZSBwYXRjaGVzIHdpbGwgZ28gaW4gc3RhYmxlIGF0IHRoZSAKcmVsZXZhbnQg dGltZS4KCkNocmlzdG9waGUKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fCmxpbnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4LWFybS1rZXJuZWxA bGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xp c3RpbmZvL2xpbnV4LWFybS1rZXJuZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [RFC PATCH v2 0/3] mm/gup: fix gup_fast with dynamic page table folding References: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> From: Christophe Leroy Message-ID: <9f9acde7-c400-53b0-38ec-ad3e48de5371@csgroup.eu> Date: Tue, 8 Sep 2020 06:42:50 +0200 MIME-Version: 1.0 In-Reply-To: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> Content-Language: fr List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: Gerald Schaefer , Jason Gunthorpe , John Hubbard Cc: Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm , Paul Mackerras , linux-sparc , Alexander Gordeev , Claudio Imbrenda , Will Deacon , linux-arch , linux-s390 , Vasily Gorbik , Richard Weinberger , linux-x86 , Russell King , Christian Borntraeger , Ingo Molnar , Andrey Ryabinin , Jeff Dike , Arnd Bergmann , Heiko Carstens , linux-um , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm , Linus Torvalds , LKML , Andrew Morton , linux-power , Mike Rapoport CgpMZSAwNy8wOS8yMDIwIMOgIDIwOjAwLCBHZXJhbGQgU2NoYWVmZXIgYSDDqWNyaXTCoDoKPiBU aGlzIGlzIHYyIG9mIGFuIFJGQyBwcmV2aW91c2x5IGRpc2N1c3NlZCBoZXJlOgo+IGh0dHBzOi8v bG9yZS5rZXJuZWwub3JnL2xrbWwvMjAyMDA4MjgxNDAzMTQuODU1Ni0xLWdlcmFsZC5zY2hhZWZl ckBsaW51eC5pYm0uY29tLwo+IAo+IFBhdGNoIDEgaXMgYSBmaXggZm9yIGEgcmVncmVzc2lvbiBp biBndXBfZmFzdCBvbiBzMzkwLCBhZnRlciBvdXIgY29udmVyc2lvbgo+IHRvIGNvbW1vbiBndXBf ZmFzdCBjb2RlLiBJdCB3aWxsIGludHJvZHVjZSBzcGVjaWFsIGhlbHBlciBmdW5jdGlvbnMKPiBw WGRfYWRkcl9lbmRfZm9sZGVkKCksIHdoaWNoIGhhdmUgdG8gYmUgdXNlZCBpbiBwbGFjZXMgd2hl cmUgcGFnZXRhYmxlIHdhbGsKPiBpcyBkb25lIHcvbyBsb2NrIGFuZCB3aXRoIFJFQURfT05DRSwg c28gY3VycmVudGx5IG9ubHkgaW4gZ3VwX2Zhc3QuCj4gCj4gUGF0Y2ggMiBpcyBhbiBhdHRlbXB0 IHRvIG1ha2UgdGhhdCBtb3JlIGdlbmVyaWMsIGkuZS4gY2hhbmdlIHBYZF9hZGRyX2VuZCgpCj4g dGhlbXNlbHZlcyBieSBhZGRpbmcgYW4gZXh0cmEgcFhkIHZhbHVlIHBhcmFtZXRlci4gVGhhdCB3 YXMgc3VnZ2VzdGVkIGJ5Cj4gSmFzb24gZHVyaW5nIHYxIGRpc2N1c3Npb24sIGJlY2F1c2UgaGUg aXMgYWxyZWFkeSB0aGlua2luZyBvZiBzb21lIG90aGVyCj4gcGxhY2VzIHdoZXJlIGhlIG1pZ2h0 IHdhbnQgdG8gc3dpdGNoIHRvIHRoZSBSRUFEX09OQ0UgbG9naWMgZm9yIHBhZ2V0YWJsZQo+IHdh bGtzLiBJbiBnZW5lcmFsLCB0aGF0IHdvdWxkIGJlIHRoZSBjbGVhbmVzdCAvIHNhZmVzdCBzb2x1 dGlvbiwgYnV0IHRoZXJlCj4gaXMgc29tZSBpbXBhY3Qgb24gb3RoZXIgYXJjaGl0ZWN0dXJlcyBh bmQgY29tbW9uIGNvZGUsIGhlbmNlIHRoZSBuZXcgYW5kCj4gZ3JlYXRseSBlbmxhcmdlZCByZWNp cGllbnQgbGlzdC4KPiAKPiBQYXRjaCAzIGlzIGEgIm5pY2UgdG8gaGF2ZSIgYWRkLW9uLCB3aGlj aCBtYWtlcyBwWGRfYWRkcl9lbmQoKSBpbmxpbmUKPiBmdW5jdGlvbnMgaW5zdGVhZCBvZiAjZGVm aW5lcywgc28gdGhhdCB3ZSBnZXQgc29tZSB0eXBlIGNoZWNraW5nIGZvciB0aGUKPiBuZXcgcFhk IHZhbHVlIHBhcmFtZXRlci4KPiAKPiBOb3Qgc3VyZSBhYm91dCBGaXhlcy9zdGFibGUgdGFncyBm b3IgdGhlIGdlbmVyaWMgc29sdXRpb24uIE9ubHkgcGF0Y2ggMQo+IGZpeGVzIGEgcmVhbCBidWcg b24gczM5MCwgYW5kIGhhcyBGaXhlcy9zdGFibGUgdGFncy4gUGF0Y2hlcyAyICsgMyBtaWdodAo+ IHN0aWxsIGJlIG5pY2UgdG8gaGF2ZSBpbiBzdGFibGUsIHRvIGVhc2UgZnV0dXJlIGJhY2twb3J0 cywgYnV0IEkgZ3Vlc3MKPiAibmljZSB0byBoYXZlIiBkb2VzIG5vdCByZWFsbHkgcXVhbGlmeSBm b3Igc3RhYmxlIGJhY2twb3J0cy4KCklmIG9uZSBkYXkgeW91IGhhdmUgdG8gYmFja3BvcnQgYSBm aXggdGhhdCByZXF1aXJlcyBwYXRjaCAyIGFuZC9vciAzLCAKanVzdCBtYXJrIGl0ICJkZXBlbmRz LW9uOiIgYW5kIHRoZSBwYXRjaGVzIHdpbGwgZ28gaW4gc3RhYmxlIGF0IHRoZSAKcmVsZXZhbnQg dGltZS4KCkNocmlzdG9waGUKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fCmxpbnV4LXVtIG1haWxpbmcgbGlzdApsaW51eC11bUBsaXN0cy5pbmZyYWRlYWQu b3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtdW0K