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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, 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 2868FC282DA for ; Wed, 17 Apr 2019 16:57:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA1D220674 for ; Wed, 17 Apr 2019 16:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555520243; bh=IiiSQ0uwBOM/gPOfTLVTC9s9Pow/Mp2zFXO0aN6M04Y=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=2RlfoLxjxm40dEXfXVfGfVW3h4XoqFZua9T0D0kFy7KgifMa30NNyMJ4MsWu7qF0Z mo7ZolR96jaLqcTuCrsrg8UAXOq0+n7K9oMCp5+LUF11vDKqKN/aJPy1aFGP/5q0jt he81ehzFSeaibJ0Fs2ySjlBE0KHHxh5BokaCfp/o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732938AbfDQQ5V (ORCPT ); Wed, 17 Apr 2019 12:57:21 -0400 Received: from mail-lj1-f195.google.com ([209.85.208.195]:45469 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729512AbfDQQ5V (ORCPT ); Wed, 17 Apr 2019 12:57:21 -0400 Received: by mail-lj1-f195.google.com with SMTP id y6so23090175ljd.12 for ; Wed, 17 Apr 2019 09:57:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=e9lZbMtDKygZ2DfMvT54TFa3e24d9xoZ0epEXOcQrX0=; b=N1H+13ULwDC+M3GXrj0q6BqQVsZgIPGQQAt1qzjWjlIE2T3boxhwovLMZhBRInW+IS wGCznU07ozdKWbn2wFvSHWvS+yOaeLs4ZmJ0A9AX+Ug2O610w4Na6yKcpLJzcVB8F4aS GdDoIQNJE32V1sSKg5NVPyl80P4+PPTryGbw4= 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; bh=e9lZbMtDKygZ2DfMvT54TFa3e24d9xoZ0epEXOcQrX0=; b=Izx9TxIG3BI1W9Jo2Jb6D4koMNNKD0xYYgfwkZkm4BkIamnOkh7h+lydD3v7W8WWNq WOqJvuvKRQUevhHk4aoJo1pnDFNMut0ZFDUm82+ir+14t05li3AtCWYeeIvr6Zzi7bf7 69LnqElkd07Pa7y+R74cLCqMrFlYfPQNWTnqARwt8+NBLDTZh59wJbtdYRSOFnRnsAgo E8KXJAfYGTqdXRm5zJSrLp7LKRc96PqCrycMKSmKy0ov5VMUEgHln+Snq7D0fdZF3oYo +yJcStNzPBChaVb+b0Z0/0/2t3xoc3WUXqVWON5DnBJZOGdOfMesPBUFncICC458ttl1 /Luw== X-Gm-Message-State: APjAAAVk4M3rKXXFZe66vttWQVE8lY5OjHY4bC/VWYfHchKDhwyRCBDi pQ8eIfDX+8G5QEh1PzYTJjpjNURoGqo= X-Google-Smtp-Source: APXvYqz8oVuqAgIN6bBJbggxNlVzn+4GRWGkbyOrO94dDF0n3MOz7CFHPG36ICLgF+HUuyvRXYkpsw== X-Received: by 2002:a2e:204e:: with SMTP id g75mr14098181ljg.92.1555520238841; Wed, 17 Apr 2019 09:57:18 -0700 (PDT) Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com. [209.85.167.49]) by smtp.gmail.com with ESMTPSA id s24sm10986690ljs.30.2019.04.17.09.57.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Apr 2019 09:57:17 -0700 (PDT) Received: by mail-lf1-f49.google.com with SMTP id u17so19444949lfi.3 for ; Wed, 17 Apr 2019 09:57:17 -0700 (PDT) X-Received: by 2002:a19:48c9:: with SMTP id v192mr29389550lfa.136.1555520237474; Wed, 17 Apr 2019 09:57:17 -0700 (PDT) MIME-Version: 1.0 References: <20190415051919.GA31481@infradead.org> <20190416110906.6c773aff@mschwideX1> <20190416140658.2cb73a3f@mschwideX1> <20190417094637.51ad4c67@mschwideX1> <20190417100244.42e29736@mschwideX1> In-Reply-To: <20190417100244.42e29736@mschwideX1> From: Linus Torvalds Date: Wed, 17 Apr 2019 09:57:01 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Linux 5.1-rc5 To: Martin Schwidefsky Cc: Christoph Hellwig , Linux List Kernel Mailing , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-s390 Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 17, 2019 at 1:02 AM Martin Schwidefsky wrote: > > Grumpf, that does *not* work. For gup the table entries may be read only > once. Now I remember why I open-coded p4d_offset, pud_offset and pmd_offset > in arch/s390/mm/gup.c, to avoid to read the table entries twice. > It will be hard to use the common gup code after all. Hmm. The common gup code generally should do the "read only once" thing too (since by definition the gup-fast case is done without locking), although it's probably the case that most architectures simply don't care. What would it require for the generic code to work for s390? Linus