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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 29DA0C282E3 for ; Thu, 25 Apr 2019 08:22:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C9673214AE for ; Thu, 25 Apr 2019 08:22:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9673214AE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4A0436B0005; Thu, 25 Apr 2019 04:22:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 44E7D6B0006; Thu, 25 Apr 2019 04:22:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 318476B0007; Thu, 25 Apr 2019 04:22:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by kanga.kvack.org (Postfix) with ESMTP id EDF1F6B0005 for ; Thu, 25 Apr 2019 04:22:49 -0400 (EDT) Received: by mail-pf1-f199.google.com with SMTP id l74so13556458pfb.23 for ; Thu, 25 Apr 2019 01:22:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:date:from:to :cc:subject:references:mime-version:content-disposition:in-reply-to :user-agent:message-id; bh=86ej6AFPgp0K+2jwAZQqD9mO+s20zKvhtCMT24j/Jog=; b=rh8+YS3MJq31H8ZoRhl9n87HX2LAiO9GI7zASwpimFWnLHjmgjFd+leGdF2RZlq5e5 UgOZUvAFLCK6YOiFmdGVUnA1DsDZOTGp//W8qqm3OWrWFmH6iLJxYKXgqYL2ly+/McgV jt9tU38Y7mRJ0g/l6aEPKFGSoSO1KcLZGq3ewbd6zr5Rhj+AAmNEMAqNjYhuZb13QDwN 7yHwAWM6S2Zk5+mDx3EvCBg7p2qTP+JPpZnOrlL7xSrDSc2X7w5ekDnrz9IfMx0o03sg cjXagpASdN5NCh6JtsfmzgM8IHo+6L1yebGeB449y55rRM271y9J0bBEi5RJu5YzW4o0 Nesg== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of rppt@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=rppt@linux.ibm.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=ibm.com X-Gm-Message-State: APjAAAX1PYj5ymf068V8rVo/Si1zBlQiU7I7AlUJ9CN5xbMOECoOrjZF MEdRTS9mAuBXEgz3eluyJms4HWLiQVm/5cKAWQ1I8GNJzvF79/M+hEKWv1UYjJdKWQesatAcO+6 HuhP2MSPQJLd0Rqox2mgr69k1rTnTer0AgC5ML73cAei1bODNLH3vKmNfubHuU8MyGQ== X-Received: by 2002:a62:69c2:: with SMTP id e185mr38577572pfc.119.1556180569643; Thu, 25 Apr 2019 01:22:49 -0700 (PDT) X-Google-Smtp-Source: APXvYqzPcUt7ngzamfgPzofELbEF3jlPcIWPliyeeOs2MPb3QpVz8YMCnxOi60MBiu5622QmJAJR X-Received: by 2002:a62:69c2:: with SMTP id e185mr38577518pfc.119.1556180568855; Thu, 25 Apr 2019 01:22:48 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1556180568; cv=none; d=google.com; s=arc-20160816; b=vn6z2oXNkvFPyjBa2dm5BZPzhzb4Q0TMxJUU5dzaIBC6lzWym2Oc7AIjdQ0UlEj9mO jQpzuNIoOm/k9RoT0dkWOmB5dhqEGKvnGjxnJPgOfVNAtuYaHHn/G0I96MzldPXisNDl S1quRhhTDP1Q7oVyf60+K+El/qfnAJR/qdOGeSBVs3rJwdK5xaFprMzPebDRP1+RNhzb 5OnCNDSlYq8tHFbINQT2zO9370SXCnaZtF3V3SZjCBOVkM/++95O+5wWX2XGGBHOEsDM Oi48kTvy5G1lARmQltYMkB24vABRS9gexm/qhZpMs1rGyIAYQI5efvklGNu7EOVzY3nu rUMg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:user-agent:in-reply-to:content-disposition:mime-version :references:subject:cc:to:from:date; bh=86ej6AFPgp0K+2jwAZQqD9mO+s20zKvhtCMT24j/Jog=; b=ZVNeq08XlB/1FUoBTLkesf21Pvz09/J7csVVlpwWw7ec3h61mCReGTjfz8cS8enU7H quVIw4n0VwA0YwN9DJ/0DGIeCFRsmaBO6BZ/iyQltbMr50GSzxTEvpRQ94HXg2PZtASK tfR8GEqCB+Gp+mgKHsYakxz+NqnpQ0r+KAOelRiy/Y9ZRlGQSQs/O2Abh+6voErcmqFM 9qhG0hvmejYs+LmEtqWjLq+DS1voMMtyr0hWQz8oy01olyUWEFEbqK16qTxFf6qBhWkr BNQv6FfyoOMBykTqt1oTJ+YVe0NHbkhbERETEpl8b/hKIX4tDrIB+T9Cl9A6+q11Avkv EmSA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of rppt@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=rppt@linux.ibm.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id z11si19870123pgu.285.2019.04.25.01.22.48 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Apr 2019 01:22:48 -0700 (PDT) Received-SPF: pass (google.com: domain of rppt@linux.ibm.com designates 148.163.156.1 as permitted sender) client-ip=148.163.156.1; Authentication-Results: mx.google.com; spf=pass (google.com: domain of rppt@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=rppt@linux.ibm.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=ibm.com Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3P84oCx107383 for ; Thu, 25 Apr 2019 04:22:48 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2s382137dg-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 25 Apr 2019 04:22:48 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 25 Apr 2019 09:22:45 +0100 Received: from b06cxnps4075.portsmouth.uk.ibm.com (9.149.109.197) by e06smtp02.uk.ibm.com (192.168.101.132) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 25 Apr 2019 09:22:43 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3P8Mgcd46530680 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 25 Apr 2019 08:22:42 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B0DCF11C052; Thu, 25 Apr 2019 08:22:42 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F2F1B11C058; Thu, 25 Apr 2019 08:22:41 +0000 (GMT) Received: from rapoport-lnx (unknown [9.148.205.63]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Thu, 25 Apr 2019 08:22:41 +0000 (GMT) Date: Thu, 25 Apr 2019 11:22:40 +0300 From: Mike Rapoport To: Randy Dunlap Cc: Jonathan Corbet , linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] docs/vm: add documentation of memory models References: <1556101715-31966-1-git-send-email-rppt@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 19042508-0008-0000-0000-000002DF50E6 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19042508-0009-0000-0000-0000224BA941 Message-Id: <20190425082239.GC10625@rapoport-lnx> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-25_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=939 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904250056 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Randy, On Wed, Apr 24, 2019 at 06:08:46PM -0700, Randy Dunlap wrote: > On 4/24/19 3:28 AM, Mike Rapoport wrote: > > Describe what {FLAT,DISCONTIG,SPARSE}MEM are and how they manage to > > maintain pfn <-> struct page correspondence. > > > > Signed-off-by: Mike Rapoport > > --- > > Documentation/vm/index.rst | 1 + > > Documentation/vm/memory-model.rst | 171 ++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 172 insertions(+) > > create mode 100644 Documentation/vm/memory-model.rst > > > > Hi Mike, > I have a few minor edits below... I kinda expected those ;-) > > diff --git a/Documentation/vm/memory-model.rst b/Documentation/vm/memory-model.rst > > new file mode 100644 > > index 0000000..914c52a > > --- /dev/null > > +++ b/Documentation/vm/memory-model.rst ... > > + > > +With FLATMEM, the conversion between a PFN and the `struct page` is > > +straightforward: `PFN - ARCH_PFN_OFFSET` is an index to the > > +`mem_map` array. > > + > > +The `ARCH_PFN_OFFSET` defines the first page frame number for > > +systems that their physical memory does not start at 0. > > s/that/when/ ? Seems awkward as is. Yeah, it is awkward. How about The `ARCH_PFN_OFFSET` defines the first page frame number for systems with physical memory starting at address different from 0. > > + > > +DISCONTIGMEM > > +============ > > + > > thanks. > -- > ~Randy > -- Sincerely yours, Mike.