Received: by 2002:a25:ad19:0:0:0:0:0 with SMTP id y25csp687662ybi; Fri, 2 Aug 2019 02:37:50 -0700 (PDT) X-Google-Smtp-Source: APXvYqzkK9PCVFcPGZPzTFppMIwOObv4n8H7C4h13asuNoha/QyQbo+MQkM+yZ4vGxpU+2Ze9JNv X-Received: by 2002:a62:1ac8:: with SMTP id a191mr58798185pfa.164.1564738670662; Fri, 02 Aug 2019 02:37:50 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1564738670; cv=none; d=google.com; s=arc-20160816; b=qroZryTjeAOS2DHFO7CTFCqaRH8hO8BqKvbI4yDHIdIFKRVcn2yBAfGXp+jw62gI+m jS7axFJkptxcxDjk1z36+3cULIXmGjJyagAxz/Y/MRl+Wep5To49SCiNspH0mKkWzASC BfpzLG0te/EaFAOxySEuyrVuG+Q2GahDfFQUTgQ63PI70dJsHJSyOPvxZJd7Eh+pEsyS 5TQ9EXJLTwO+GJG1YcmBCb9NuRedSN3R2tqORi45+gmqMtl7Q03OYq/elBXzriqxvckP NRsNcJGTChbKA+0F4RSavoEEiW8rU4Uh6nOypiFmWo8hgnR1D9JYrHBj8jNLfC5oZPzU rFjw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=xDMaIKJ3eqki9Hr/c8pax1SD09nlwwoubgEtYUZaCik=; b=C2vYNwEnwkF5ZovFdjEv0dj5vE51lxpfsy3TVo4LqQnM8aBKsIKjmUXkM0TnuEXarp yUQ9PpTyXOSBw8jW8P7TX82EBmnoQP5dfHj8jS52P8HxbnMYiDNAyrK3/70GaGPWQi2d wXtJBNC2kEZjGXRInff8ipua2ThpEgujPy0U3wlLp9Z5aVRK6lePE65An/u7/XRnvYEq aP2VwLn8bUYltJpjHXvxdLLL9ikdbEfR+axkh9ISvEsYeN5TGFL/rsOPQW5G1V69Vg5X XvUoVTm9JEmuRgYK/hIi0tqYU5Ce0ZeW4PSug6YIcNtzIj7+o4w8MhU5bgROY9krqJst IgzQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-nfs-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-nfs-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id c189si49825233pfa.110.2019.08.02.02.37.36; Fri, 02 Aug 2019 02:37:50 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-nfs-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-nfs-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-nfs-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732804AbfHBJMv (ORCPT + 99 others); Fri, 2 Aug 2019 05:12:51 -0400 Received: from mx2.suse.de ([195.135.220.15]:54294 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727127AbfHBJMu (ORCPT ); Fri, 2 Aug 2019 05:12:50 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 4990DAFE2; Fri, 2 Aug 2019 09:12:47 +0000 (UTC) Date: Fri, 2 Aug 2019 11:12:44 +0200 From: Michal Hocko To: john.hubbard@gmail.com Cc: Andrew Morton , Christoph Hellwig , Dan Williams , Dave Chinner , Dave Hansen , Ira Weiny , Jan Kara , Jason Gunthorpe , =?iso-8859-1?B?Suly9G1l?= Glisse , LKML , amd-gfx@lists.freedesktop.org, ceph-devel@vger.kernel.org, devel@driverdev.osuosl.org, devel@lists.orangefs.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-crypto@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-media@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-xfs@vger.kernel.org, netdev@vger.kernel.org, rds-devel@oss.oracle.com, sparclinux@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org, John Hubbard Subject: Re: [PATCH 00/34] put_user_pages(): miscellaneous call sites Message-ID: <20190802091244.GD6461@dhcp22.suse.cz> References: <20190802022005.5117-1-jhubbard@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190802022005.5117-1-jhubbard@nvidia.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Thu 01-08-19 19:19:31, john.hubbard@gmail.com wrote: [...] > 2) Convert all of the call sites for get_user_pages*(), to > invoke put_user_page*(), instead of put_page(). This involves dozens of > call sites, and will take some time. How do we make sure this is the case and it will remain the case in the future? There must be some automagic to enforce/check that. It is simply not manageable to do it every now and then because then 3) will simply be never safe. Have you considered coccinele or some other scripted way to do the transition? I have no idea how to deal with future changes that would break the balance though. -- Michal Hocko SUSE Labs