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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 AD321C433DF for ; Thu, 11 Jun 2020 01:41:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6CFB9207ED for ; Thu, 11 Jun 2020 01:41:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="2o2GF7yo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6CFB9207ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1A24B8D0060; Wed, 10 Jun 2020 21:41:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 152068D004C; Wed, 10 Jun 2020 21:41:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F0D3E8D0060; Wed, 10 Jun 2020 21:41:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0244.hostedemail.com [216.40.44.244]) by kanga.kvack.org (Postfix) with ESMTP id DD2E88D004C for ; Wed, 10 Jun 2020 21:41:52 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id AC905802567E for ; Thu, 11 Jun 2020 01:41:52 +0000 (UTC) X-FDA: 76915229664.21.rub11_0f0d1d226dcf Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin21.hostedemail.com (Postfix) with ESMTP id 8C6951804474F for ; Thu, 11 Jun 2020 01:41:52 +0000 (UTC) X-HE-Tag: rub11_0f0d1d226dcf X-Filterd-Recvd-Size: 3001 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf36.hostedemail.com (Postfix) with ESMTP for ; Thu, 11 Jun 2020 01:41:52 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 48A592078D; Thu, 11 Jun 2020 01:41:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591839711; bh=O4cmHu1pn+zoon3o4WF6tL2zmvsQnLrVOmhnApoJy3k=; h=Date:From:To:Subject:In-Reply-To:From; b=2o2GF7yoY+bYMIK97moHNEystGWziz+LdP/q75S7xGjX5ATPBFKwMbZRB1nbusz0L g+6DQp432D3YyGo2P/qe0rchXVSsPfwnULvr9BzGRBJtybvpn36i0B2alugW50eXod 8bQkaQzoL8yfchwEiwktnPQM/gSq8NcpQeKUb3XM= Date: Wed, 10 Jun 2020 18:41:50 -0700 From: Andrew Morton To: akpm@linux-foundation.org, ben.widawsky@intel.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 10/25] mm: add comments on pglist_data zones Message-ID: <20200611014150.9MNWkw05i%akpm@linux-foundation.org> In-Reply-To: <20200610184053.3fa7368ab80e23bfd44de71f@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: 8C6951804474F X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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: From: Ben Widawsky Subject: mm: add comments on pglist_data zones While making other modifications it was easy to confuse the two struct members node_zones and node_zonelists. For those already familiar with the code, this might seem to be a silly patch, but it's quite helpful to disambiguate the similar-sounding fields While here, add a small comment on why nr_zones isn't simply MAX_NR_ZONES Link: http://lkml.kernel.org/r/20200520205443.2757414-1-ben.widawsky@intel.com Signed-off-by: Ben Widawsky Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton --- include/linux/mmzone.h | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/include/linux/mmzone.h~mm-add-comments-on-pglist_data-zones +++ a/include/linux/mmzone.h @@ -660,9 +660,21 @@ struct deferred_split { * per-zone basis. */ typedef struct pglist_data { + /* + * node_zones contains just the zones for THIS node. Not all of the + * zones may be populated, but it is the full list. It is referenced by + * this node's node_zonelists as well as other node's node_zonelists. + */ struct zone node_zones[MAX_NR_ZONES]; + + /* + * node_zonelists contains references to all zones in all nodes. + * Generally the first zones will be references to this node's + * node_zones. + */ struct zonelist node_zonelists[MAX_ZONELISTS]; - int nr_zones; + + int nr_zones; /* number of populated zones in this node */ #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */ struct page *node_mem_map; #ifdef CONFIG_PAGE_EXTENSION _