From patchwork Thu Jun 11 01:41:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11599061 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8F8A7739 for ; Thu, 11 Jun 2020 01:41:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5CBF42081A for ; Thu, 11 Jun 2020 01:41:54 +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 5CBF42081A 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) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 152068D004C; Wed, 10 Jun 2020 21:41:53 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org 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-Original-To: linux-mm@kvack.org 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-Spam-Summary: 2,0,0,c997be9c6b45d19f,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2393:2525:2553:2559:2563:2682:2685:2693:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3865:3866:3867:3868:3870:3871:3872:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4250:4321:5007:6119:6261:6653:7576:7882:7903:8599:8784:9010:9025:9545:10004:10913:11026:11473:11658:11914:12043:12048:12296:12297:12438:12517:12519:12555:12679:12783:12986:13069:13161:13229:13311:13357:13846:14181:14384:14721:14849:21080:21451:21627:21939:21972:30012:30034:30054:30064:30090,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:25,LUA_SUMMARY:none 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