From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.6 required=5.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 5D6E87D043 for ; Mon, 18 Jun 2018 17:21:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934957AbeFRRVd (ORCPT ); Mon, 18 Jun 2018 13:21:33 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:58010 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934215AbeFRRVd (ORCPT ); Mon, 18 Jun 2018 13:21:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To: Subject:Sender:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=R2/XQ1TMiQoV9vTqGhJPmvQYUHOxnlYsEgJJvd/vI3w=; b=PmYIcHXgiVhd8jGydYaIz4oez LP4G3tVyn86UP3JJBevqW8sxYZgubEDeH62zFDiDKNhqb7DJ+9/I/BC5S+Wrkw/7+1J1Wx5+Wq83P trcipOX3r5QO7bpm1TixjTZ9i4X2rSqgVPtibBSZIesHLEm6DTyY2jPtbox62PxyATcFCscLtCZyE bhyQU9Suv2YS421lUzTr+eoLP6tG8SpSDDuDmyWYMIIGcBMHR74Cl9oqEGiQ36BoyBlHN34QBJTFg aQKSr/fSSyDjVzZamfj8ET9ZVym8At8370AiSTwMUJXTyHUYcksup8veNDcmwsa3fMnYx1yE2uvSv jsQZnqV6A==; Received: from static-50-53-52-16.bvtn.or.frontiernet.net ([50.53.52.16] helo=midway.dunlab) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fUxqO-0002eQ-2y; Mon, 18 Jun 2018 17:21:32 +0000 Subject: Re: [PATCH 10/11] docs/mm: memblock: add overview documentation To: Mike Rapoport , Jonathan Corbet Cc: Andrew Morton , linux-doc , linux-mm , lkml References: <1529341199-17682-1-git-send-email-rppt@linux.vnet.ibm.com> <1529341199-17682-11-git-send-email-rppt@linux.vnet.ibm.com> From: Randy Dunlap Message-ID: Date: Mon, 18 Jun 2018 10:21:31 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <1529341199-17682-11-git-send-email-rppt@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi, On 06/18/2018 09:59 AM, Mike Rapoport wrote: > Signed-off-by: Mike Rapoport > --- > mm/memblock.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 55 insertions(+) > > diff --git a/mm/memblock.c b/mm/memblock.c > index c4838a9..8bfeb82 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -26,6 +26,61 @@ > > #include "internal.h" > > +/** > + * DOC: memblock overview > + * > + * Memblock is a method of managing memory regions during the early > + * boot period when the usual kernel memory allocators are not up and > + * running. > + * > + * Memblock views the system memory as collections of contiguous > + * regions. There are several types of these collections: > + * > + * * ``memory`` - describes the physical memory available to the > + * kernel; this may differ from the actual physical memory installed > + * in the system, for instance when the memory is restricted with > + * ``mem=`` command line parameter > + * * ``reserved`` - describes the regions that were allocated > + * * ``physmap`` - describes the actual physical memory regardless of > + * the possible restrictions; the ``physmap`` type is only available > + * on some architectures. > + * > + * Each region is represented by :c:type:`struct memblock_region` that > + * defines the region extents, its attributes and NUMA node id on NUMA > + * systems. Every memory type is described by the :c:type:`struct > + * memblock_type` which contains an array of memory regions along with > + * the allocator metadata. The memory types are nicely wrapped with > + * :c:type:`struct memblock`. This structure is statically initialzed > + * at build time. The region arrays for the "memory" and "reserved" > + * types are initially sized to %INIT_MEMBLOCK_REGIONS and for the > + * "physmap" type to %INIT_PHYSMEM_REGIONS. > + * The :c:func:`memblock_allow_resize` enables automatic resizing of > + * the region arrays during addition of new regions. This feature > + * should be used with care so that memory allocated for the region > + * array will not overlap with areas that should be reserved, for > + * example initrd. > + * > + * The early architecture setup should tell memblock what is the The early architecture setup should tell memblock what the physical memory layout is by using :c:func:`memblock_add` or > + * physical memory layout using :c:func:`memblock_add` or > + * :c:func:`memblock_add_node` functions. The first function does not > + * assign the region to a NUMA node and it is approptiate for UMA appropriate > + * systems. Yet, it is possible to use it on NUMA systems as well and > + * assign the region to a NUMA node later in the setup process using > + * :c:func:`memblock_set_node`. The :c:func:`memblock_add_node` > + * performs such an assignment directly. > + * > + * Once memblock is setup the memory can be allocated using either > + * memblock or bootmem APIs. > + * > + * As the system boot progresses, the architecture specific > + * :c:func:`mem_init` function frees all the memory to the buddy page > + * allocator. > + * > + * If an architecure enables %CONFIG_ARCH_DISCARD_MEMBLOCK, the > + * memblock data structures will be discarded after the system > + * intialization compltes initialization completes. > + */ > + > static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock; > static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock; > #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP > -- ~Randy -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html