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=-1.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,SUBJ_ALL_CAPS,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 4E8C4C32750 for ; Tue, 13 Aug 2019 09:29:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D60B20673 for ; Tue, 13 Aug 2019 09:29:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727298AbfHMJ3N (ORCPT ); Tue, 13 Aug 2019 05:29:13 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:39665 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726516AbfHMJ3M (ORCPT ); Tue, 13 Aug 2019 05:29:12 -0400 Received: by mail-wm1-f66.google.com with SMTP id i63so831896wmg.4 for ; Tue, 13 Aug 2019 02:29:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=HlAEpqymIE/2aXmWh9O2C6f1zWhZyF+vIZxr8hLy7E8=; b=ogMTSFSp6/5qD7QNpJ+bVDWuolW07yskkKFXi/Xt/SVCWiF+RjA5tWNg0Fs7ph3bUv /Zlup0zUb7JQ4TNCOvdbW6GTHA97Ws8hx0EDCuXZg0+DSMNZZqyk9IICwtHTcK9Wvuq3 mlpFbaYcrPmtYDj1xxDPW+WHG0Vu+7uouiXy+qEs9lRTN9vhal/1aWSxm7XxrWjZ8xZf HWqc6mePDPdWtr1d+W+lX3fZlVWjnBixb3l9z4vmCEMRm+8k4QGgGRnpQcF+0JZsz5KJ LBQGmF5PT7BIgaHixkgcXXYS5NbqvFdYnlY+MjHBdY711TelsBi5jKtFsi7HPF3WLvIa pM4Q== X-Gm-Message-State: APjAAAVUwMmENWBAyjJfhcZJj3udw6sfVr/o9nQGdJqUQhBBmH1nwd21 vCj0WMfRn09IdLdgKd29LW5LQORlVbc= X-Google-Smtp-Source: APXvYqzrOiKUATXICk0r/wqqOqYzdUlD6b5RE1HxjJCFGhp5IL3oELH2ehl1knzxc0AKbs6tiQAFDw== X-Received: by 2002:a7b:c198:: with SMTP id y24mr2019539wmi.131.1565688550614; Tue, 13 Aug 2019 02:29:10 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:5d12:7fa9:fb2d:7edb? ([2001:b07:6468:f312:5d12:7fa9:fb2d:7edb]) by smtp.gmail.com with ESMTPSA id f134sm1257977wmg.20.2019.08.13.02.29.09 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Tue, 13 Aug 2019 02:29:10 -0700 (PDT) Subject: Re: DANGER WILL ROBINSON, DANGER To: Matthew Wilcox , =?UTF-8?Q?Adalbert_Laz=c4=83r?= Cc: kvm@vger.kernel.org, linux-mm@kvack.org, virtualization@lists.linux-foundation.org, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Konrad Rzeszutek Wilk , Tamas K Lengyel , Mathieu Tarral , =?UTF-8?Q?Samuel_Laur=c3=a9n?= , Patrick Colp , Jan Kiszka , Stefan Hajnoczi , Weijiang Yang , Zhang@kvack.org, Yu C , =?UTF-8?Q?Mihai_Don=c8=9bu?= , =?UTF-8?Q?Mircea_C=c3=aerjaliu?= References: <20190809160047.8319-1-alazar@bitdefender.com> <20190809160047.8319-72-alazar@bitdefender.com> <20190809162444.GP5482@bombadil.infradead.org> From: Paolo Bonzini Openpgp: preference=signencrypt Message-ID: Date: Tue, 13 Aug 2019 11:29:07 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190809162444.GP5482@bombadil.infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 09/08/19 18:24, Matthew Wilcox wrote: > On Fri, Aug 09, 2019 at 07:00:26PM +0300, Adalbert Lazăr wrote: >> +++ b/include/linux/page-flags.h >> @@ -417,8 +417,10 @@ PAGEFLAG(Idle, idle, PF_ANY) >> */ >> #define PAGE_MAPPING_ANON 0x1 >> #define PAGE_MAPPING_MOVABLE 0x2 >> +#define PAGE_MAPPING_REMOTE 0x4 > Uh. How do you know page->mapping would otherwise have bit 2 clear? > Who's guaranteeing that? > > This is an awfully big patch to the memory management code, buried in > the middle of a gigantic series which almost guarantees nobody would > look at it. I call shenanigans. Are you calling shenanigans on the patch submitter (which is gratuitous) or on the KVM maintainers/reviewers? It's not true that nobody would look at it. Of course no one from linux-mm is going to look at it, but the maintainer that looks at the gigantic series is very much expected to look at it and explain to the submitter that this patch is unacceptable as is. In fact I shouldn't have to to explain this to you; you know better than believing that I would try to sneak it past the mm folks. I am puzzled. Paolo