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=-15.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 00ED9C48BCF for ; Wed, 9 Jun 2021 10:58:08 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B4DD16136D for ; Wed, 9 Jun 2021 10:58:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4DD16136D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:Cc:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=QzolAh9dFOmC/XAoCVK1TOUWHmJgObJW9suld5yDGHE=; b=yUb/Xv7/66naZG70McX2AYKUgL ThFvpgsOfnu1qUF+H1rn0JCxw31WvTt/KH30WaAjNhTLQahIg0gP6vWCASpnYwLC3mVmJOc+Rl/HJ 1rIiPYkCvWh8X7yBWHaoyLM7+P7sBheAR0mfph2mq0TdCD4pji/051GxpAo0BA8cJy1HAdCdFDfaK XcD8GgGFql6KVMyjecMWtdGTdJteB8DbSXAARh8FUNCrTuqqN2kgoKsZlvo/moN0SdPgpb3rGYGvy qhkhkJ22ckRL3G8LyGpt4O21YFUd43gjnQidIn4kLO6opUsub+K6jJL1i0hztfjFrxu0rjaCJyAMT gDroKh6g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqvuA-00DC0W-2f; Wed, 09 Jun 2021 10:57:50 +0000 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqvsT-00DAxO-IX for linux-riscv@lists.infradead.org; Wed, 09 Jun 2021 10:56:09 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623236164; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1eqcq/7KVFIFfww4JdqqnK/TUbif/qCxlnaAkIZ26tg=; b=XhbkTzLIxP/kCPYbdPkz2lNjcWWrTTwywSkuukPJX/ZGLAYCdC1RPoHuQWS0UbqoDw+MHH zHDpk7smthFA9q0TfeDrDNVCaxlhFEUKjKiwLCRw6HYWaBAwW6ECJIbHwP6wu40yxFzrK1 x3ggkJKDQZ3GflUqR9fny9V7F4193AU= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-39-u4mRkNuHPwapqBFnTtpaew-1; Wed, 09 Jun 2021 06:56:03 -0400 X-MC-Unique: u4mRkNuHPwapqBFnTtpaew-1 Received: by mail-wr1-f72.google.com with SMTP id m27-20020a056000025bb0290114d19822edso10602420wrz.21 for ; Wed, 09 Jun 2021 03:56:03 -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:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=1eqcq/7KVFIFfww4JdqqnK/TUbif/qCxlnaAkIZ26tg=; b=JfJ/hKLCLCjF0Lh1fn2EOSlKy/WvXuPUGvEtonbTLjgQFuSWsoZz2pge5cPv5cCPrv kU9FLuTPjDSgigx6NncYNlbxMEo3xsgZSajg4EC9tH4Ws0HgaSKhMiArfrWwhTIItw25 c5eSHOvfMeDhplNfkH2qGsoXDMgx0BCBhSyaXarDr/0q7RhqIlZRhHtDuWW0vkGPrAl6 hFIKMsxQ/iRVODamSXKL89BsDvoUdlpBOlrbdVSjIrfBH8wSODj7+mCrW/Nc6S7Stkjy s/LdlLouzfPmVSfHrzMel04SUAoQsBBP7N9vH1C1c3LiQtyUj5R/ESy7CdOIADe4/11k DSuQ== X-Gm-Message-State: AOAM532M3YXjvGxBxn+kldyveK4fJGE4rF+vNHP3F3shnSZKwKN9K7Uf ii3TRxAgq94zvDb+/hWPxJQwqplZ0t1fA6AE256sW7gmCYtMGK0Nk3KPRJ5raEmb2CkezzHU3Td U7c3/tTDuusQ7Pin90n048JDj4CZC X-Received: by 2002:adf:ee46:: with SMTP id w6mr28365894wro.345.1623236162279; Wed, 09 Jun 2021 03:56:02 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzQ49r+tRbGd1wOHU0mXbY7urMjvAihHVmP4oVaZtHRm+k2OFRov+Lj+Vo8CLpAoo+a81y7uQ== X-Received: by 2002:adf:ee46:: with SMTP id w6mr28365871wro.345.1623236162032; Wed, 09 Jun 2021 03:56:02 -0700 (PDT) Received: from [192.168.3.132] (p5b0c611d.dip0.t-ipconnect.de. [91.12.97.29]) by smtp.gmail.com with ESMTPSA id a4sm21295711wme.45.2021.06.09.03.56.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Jun 2021 03:56:01 -0700 (PDT) Subject: Re: [PATCH 7/9] docs: remove description of DISCONTIGMEM To: Mike Rapoport , Andrew Morton Cc: Arnd Bergmann , Geert Uytterhoeven , Ivan Kokshaysky , Jonathan Corbet , Matt Turner , Mike Rapoport , Richard Henderson , Vineet Gupta , kexec@lists.infradead.org, linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org References: <20210602105348.13387-1-rppt@kernel.org> <20210602105348.13387-8-rppt@kernel.org> From: David Hildenbrand Organization: Red Hat Message-ID: <6b92d273-dd0b-d67f-c2f6-cce13a33afd1@redhat.com> Date: Wed, 9 Jun 2021 12:56:00 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210602105348.13387-8-rppt@kernel.org> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210609_035605_807964_B0290780 X-CRM114-Status: GOOD ( 33.52 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On 02.06.21 12:53, Mike Rapoport wrote: > From: Mike Rapoport > > Remove description of DISCONTIGMEM from the "Memory Models" document and > update VM sysctl description so that it won't mention DISCONIGMEM. > > Signed-off-by: Mike Rapoport > --- > Documentation/admin-guide/sysctl/vm.rst | 12 +++---- > Documentation/vm/memory-model.rst | 45 ++----------------------- > 2 files changed, 8 insertions(+), 49 deletions(-) > > diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst > index 586cd4b86428..ddbd71d592e0 100644 > --- a/Documentation/admin-guide/sysctl/vm.rst > +++ b/Documentation/admin-guide/sysctl/vm.rst > @@ -936,12 +936,12 @@ allocations, THP and hugetlbfs pages. > > To make it sensible with respect to the watermark_scale_factor > parameter, the unit is in fractions of 10,000. The default value of > -15,000 on !DISCONTIGMEM configurations means that up to 150% of the high > -watermark will be reclaimed in the event of a pageblock being mixed due > -to fragmentation. The level of reclaim is determined by the number of > -fragmentation events that occurred in the recent past. If this value is > -smaller than a pageblock then a pageblocks worth of pages will be reclaimed > -(e.g. 2MB on 64-bit x86). A boost factor of 0 will disable the feature. > +15,000 means that up to 150% of the high watermark will be reclaimed in the > +event of a pageblock being mixed due to fragmentation. The level of reclaim > +is determined by the number of fragmentation events that occurred in the > +recent past. If this value is smaller than a pageblock then a pageblocks > +worth of pages will be reclaimed (e.g. 2MB on 64-bit x86). A boost factor > +of 0 will disable the feature. > > > watermark_scale_factor > diff --git a/Documentation/vm/memory-model.rst b/Documentation/vm/memory-model.rst > index ce398a7dc6cd..30e8fbed6914 100644 > --- a/Documentation/vm/memory-model.rst > +++ b/Documentation/vm/memory-model.rst > @@ -14,15 +14,11 @@ for the CPU. Then there could be several contiguous ranges at > completely distinct addresses. And, don't forget about NUMA, where > different memory banks are attached to different CPUs. > > -Linux abstracts this diversity using one of the three memory models: > -FLATMEM, DISCONTIGMEM and SPARSEMEM. Each architecture defines what > +Linux abstracts this diversity using one of the two memory models: > +FLATMEM and SPARSEMEM. Each architecture defines what > memory models it supports, what the default memory model is and > whether it is possible to manually override that default. > > -.. note:: > - At time of this writing, DISCONTIGMEM is considered deprecated, > - although it is still in use by several architectures. > - > All the memory models track the status of physical page frames using > struct page arranged in one or more arrays. > > @@ -63,43 +59,6 @@ straightforward: `PFN - ARCH_PFN_OFFSET` is an index to the > The `ARCH_PFN_OFFSET` defines the first page frame number for > systems with physical memory starting at address different from 0. > > -DISCONTIGMEM > -============ > - > -The DISCONTIGMEM model treats the physical memory as a collection of > -`nodes` similarly to how Linux NUMA support does. For each node Linux > -constructs an independent memory management subsystem represented by > -`struct pglist_data` (or `pg_data_t` for short). Among other > -things, `pg_data_t` holds the `node_mem_map` array that maps > -physical pages belonging to that node. The `node_start_pfn` field of > -`pg_data_t` is the number of the first page frame belonging to that > -node. > - > -The architecture setup code should call :c:func:`free_area_init_node` for > -each node in the system to initialize the `pg_data_t` object and its > -`node_mem_map`. > - > -Every `node_mem_map` behaves exactly as FLATMEM's `mem_map` - > -every physical page frame in a node has a `struct page` entry in the > -`node_mem_map` array. When DISCONTIGMEM is enabled, a portion of the > -`flags` field of the `struct page` encodes the node number of the > -node hosting that page. > - > -The conversion between a PFN and the `struct page` in the > -DISCONTIGMEM model became slightly more complex as it has to determine > -which node hosts the physical page and which `pg_data_t` object > -holds the `struct page`. > - > -Architectures that support DISCONTIGMEM provide :c:func:`pfn_to_nid` > -to convert PFN to the node number. The opposite conversion helper > -:c:func:`page_to_nid` is generic as it uses the node number encoded in > -page->flags. > - > -Once the node number is known, the PFN can be used to index > -appropriate `node_mem_map` array to access the `struct page` and > -the offset of the `struct page` from the `node_mem_map` plus > -`node_start_pfn` is the PFN of that page. > - > SPARSEMEM > ========= > > Reviewed-by: David Hildenbrand -- Thanks, David / dhildenb _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv