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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 D90FEC47404 for ; Wed, 9 Oct 2019 13:29:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B035821924 for ; Wed, 9 Oct 2019 13:29:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570627795; bh=KqfPVq79nF57S2ONhyrCNLEt7HeN1pXjSPo4ELOWnYc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Eyg6EwL6ZEXUtbR3x+I62xx4lWDNL/k1pNW/+W4iBZyoQXAzYc4BVbSl6uGtzWCqg lguJFI6G3PXNDBxrV0IMHglBXgkbWnNpQ3CFzKeXgwNeTMw+UDJdbzIfYdmMWfNAB/ 1HKbk/mMyTyH/2cPwgTTQt6Y+lxAS0Vt1zIW8BKw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731437AbfJIN3y (ORCPT ); Wed, 9 Oct 2019 09:29:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:48596 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731083AbfJIN3y (ORCPT ); Wed, 9 Oct 2019 09:29:54 -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 5A22DAC6E; Wed, 9 Oct 2019 13:29:52 +0000 (UTC) Date: Wed, 9 Oct 2019 15:29:50 +0200 From: Michal Hocko To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Qian Cai , Alexey Dobriyan , Naoya Horiguchi , Andrew Morton , Stephen Rothwell , Toshiki Fukasawa , Konstantin Khlebnikov , Mike Rapoport , Anthony Yznaga , Jason Gunthorpe , Dan Williams , Logan Gunthorpe , Ira Weiny , "Aneesh Kumar K.V" , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v1] mm: Fix access of uninitialized memmaps in fs/proc/page.c Message-ID: <20191009132950.GB6681@dhcp22.suse.cz> References: <20191009091205.11753-1-david@redhat.com> <20191009093756.GV6681@dhcp22.suse.cz> <67aeaacc-d850-5c81-bd17-e95c7f7f75df@redhat.com> <20191009112424.GY6681@dhcp22.suse.cz> <20191009132256.GZ6681@dhcp22.suse.cz> <8f0542f4-92c6-d450-7343-62bf9f08d5ed@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8f0542f4-92c6-d450-7343-62bf9f08d5ed@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 09-10-19 15:24:05, David Hildenbrand wrote: > On 09.10.19 15:22, Michal Hocko wrote: > > On Wed 09-10-19 14:58:24, David Hildenbrand wrote: > > [...] > >> I would be fine with this, but it means that - for now - the three > >> /proc/ files won't be able to deal with ZONE_DEVICE memory. > > > > Thanks for the clarification. Is this an actual problem though? Do we > > have any consumers of the functionality? > > > > I don't know, that's why I was being careful in not changing its behavior. Can we simply go with pfn_to_online_page. I would be quite surprised if anybody was really examining zone device memory ranges as they are static IIUC. If there is some usecase I am pretty sure we will learn that and can address it accordingly. -- Michal Hocko SUSE Labs