Received: by 2002:ac0:a581:0:0:0:0:0 with SMTP id m1-v6csp1060106imm; Fri, 29 Jun 2018 10:40:23 -0700 (PDT) X-Google-Smtp-Source: ADUXVKKABrYVwRrQkHLgHl+UQVwRItJ7ycuqBcSM8u6MwcMrgI2SQTi9MLfpzdgIi5shpyNXzZOJ X-Received: by 2002:a63:b147:: with SMTP id g7-v6mr13217510pgp.379.1530294023172; Fri, 29 Jun 2018 10:40:23 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1530294023; cv=none; d=google.com; s=arc-20160816; b=Fi0qOuwCaxx7Y9KePkpMmN3/L4TuUJlQy+++6QAlaN3dMUxqa4yGvAjNd0P2ij8yTP s3h3ry2lOcgvazLQojRFO6HCJunwjzlz3f9pxF6oxfcMgeX47p73O0Cnq1tKTRMaI1Xu ErLBH9T2ZafkE7SkOoLQ61vehquz9KyW1ajEM8rqG2JZnDKUAq4PA4/mwDkhBYosCSq5 398rKA+KozPT7AL7sLOcFPE2wIvYtwSqBZWQK/AvhDl+dVQTgaKnzn7nVEFfEoBq756Y F+yM+aeXbIBXbKqyRq3iQVgVVvYQ9FiyOrh+zrWbj7tfMQbWmdwqODhR3HMvIzPGkhFl B7TQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:autocrypt:openpgp:from:cc:references:to:subject :arc-authentication-results; bh=fhcd0AO1o1nncRpcqqbt1UyuakD0FPRHfRxWibVvVQM=; b=Y4vjDDP5uiPUNH95qyF4pmwCxa+XwxxCU5FZWelS8vesaalaD+HPdvfRU8kM7qDHJ/ eiCGHVmXywwfVB5jRISGgTu0tx0vII4h/JZd2EE554THlN9QzDgRufoVQV7k3E928Tng v7i36i/ekQXJYf5ZWf4Vp7JUz3E4uXa+gOYZsxXO1uRQoHI2+A0zEiWKDq2YBRuf/ugv 3peV1TsJVjt1AUkU2fOxP7jxLYGFqPxgyuxv1GZXLzK7f1nfR79J6C138H8ROd0YpO9Z vjkJIHxF+w01+LqEnxgpGsylahx0L+b2SgMvZWxw3SiTuYjoBDkq9OEG9SyMxr2TH02z AMLw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id v4-v6si8185380pgs.299.2018.06.29.10.40.08; Fri, 29 Jun 2018 10:40:23 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936804AbeF2RQ7 (ORCPT + 99 others); Fri, 29 Jun 2018 13:16:59 -0400 Received: from mga04.intel.com ([192.55.52.120]:56761 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932446AbeF2RQ6 (ORCPT ); Fri, 29 Jun 2018 13:16:58 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jun 2018 10:16:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,286,1526367600"; d="scan'208";a="236663280" Received: from ray.jf.intel.com (HELO [10.7.201.18]) ([10.7.201.18]) by orsmga005.jf.intel.com with ESMTP; 29 Jun 2018 10:16:57 -0700 Subject: Re: [PATCH v5 4/4] mm/sparse: Optimize memmap allocation during sparse_init() To: Baoquan He , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, pagupta@redhat.com References: <20180627013116.12411-1-bhe@redhat.com> <20180627013116.12411-5-bhe@redhat.com> Cc: linux-mm@kvack.org, kirill.shutemov@linux.intel.com From: Dave Hansen Openpgp: preference=signencrypt Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzShEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gPGRhdmVAc3I3MS5uZXQ+wsF7BBMBAgAlAhsDBgsJCAcDAgYVCAIJ CgsEFgIDAQIeAQIXgAUCTo3k0QIZAQAKCRBoNZUwcMmSsMO2D/421Xg8pimb9mPzM5N7khT0 2MCnaGssU1T59YPE25kYdx2HntwdO0JA27Wn9xx5zYijOe6B21ufrvsyv42auCO85+oFJWfE K2R/IpLle09GDx5tcEmMAHX6KSxpHmGuJmUPibHVbfep2aCh9lKaDqQR07gXXWK5/yU1Dx0r VVFRaHTasp9fZ9AmY4K9/BSA3VkQ8v3OrxNty3OdsrmTTzO91YszpdbjjEFZK53zXy6tUD2d e1i0kBBS6NLAAsqEtneplz88T/v7MpLmpY30N9gQU3QyRC50jJ7LU9RazMjUQY1WohVsR56d ORqFxS8ChhyJs7BI34vQusYHDTp6PnZHUppb9WIzjeWlC7Jc8lSBDlEWodmqQQgp5+6AfhTD kDv1a+W5+ncq+Uo63WHRiCPuyt4di4/0zo28RVcjtzlGBZtmz2EIC3vUfmoZbO/Gn6EKbYAn rzz3iU/JWV8DwQ+sZSGu0HmvYMt6t5SmqWQo/hyHtA7uF5Wxtu1lCgolSQw4t49ZuOyOnQi5 f8R3nE7lpVCSF1TT+h8kMvFPv3VG7KunyjHr3sEptYxQs4VRxqeirSuyBv1TyxT+LdTm6j4a mulOWf+YtFRAgIYyyN5YOepDEBv4LUM8Tz98lZiNMlFyRMNrsLV6Pv6SxhrMxbT6TNVS5D+6 UorTLotDZKp5+M7BTQRUY85qARAAsgMW71BIXRgxjYNCYQ3Xs8k3TfAvQRbHccky50h99TUY sqdULbsb3KhmY29raw1bgmyM0a4DGS1YKN7qazCDsdQlxIJp9t2YYdBKXVRzPCCsfWe1dK/q 66UVhRPP8EGZ4CmFYuPTxqGY+dGRInxCeap/xzbKdvmPm01Iw3YFjAE4PQ4hTMr/H76KoDbD cq62U50oKC83ca/PRRh2QqEqACvIH4BR7jueAZSPEDnzwxvVgzyeuhwqHY05QRK/wsKuhq7s UuYtmN92Fasbxbw2tbVLZfoidklikvZAmotg0dwcFTjSRGEg0Gr3p/xBzJWNavFZZ95Rj7Et db0lCt0HDSY5q4GMR+SrFbH+jzUY/ZqfGdZCBqo0cdPPp58krVgtIGR+ja2Mkva6ah94/oQN lnCOw3udS+Eb/aRcM6detZr7XOngvxsWolBrhwTQFT9D2NH6ryAuvKd6yyAFt3/e7r+HHtkU kOy27D7IpjngqP+b4EumELI/NxPgIqT69PQmo9IZaI/oRaKorYnDaZrMXViqDrFdD37XELwQ gmLoSm2VfbOYY7fap/AhPOgOYOSqg3/Nxcapv71yoBzRRxOc4FxmZ65mn+q3rEM27yRztBW9 AnCKIc66T2i92HqXCw6AgoBJRjBkI3QnEkPgohQkZdAb8o9WGVKpfmZKbYBo4pEAEQEAAcLB XwQYAQIACQUCVGPOagIbDAAKCRBoNZUwcMmSsJeCEACCh7P/aaOLKWQxcnw47p4phIVR6pVL e4IEdR7Jf7ZL00s3vKSNT+nRqdl1ugJx9Ymsp8kXKMk9GSfmZpuMQB9c6io1qZc6nW/3TtvK pNGz7KPPtaDzvKA4S5tfrWPnDr7n15AU5vsIZvgMjU42gkbemkjJwP0B1RkifIK60yQqAAlT YZ14P0dIPdIPIlfEPiAWcg5BtLQU4Wg3cNQdpWrCJ1E3m/RIlXy/2Y3YOVVohfSy+4kvvYU3 lXUdPb04UPw4VWwjcVZPg7cgR7Izion61bGHqVqURgSALt2yvHl7cr68NYoFkzbNsGsye9ft M9ozM23JSgMkRylPSXTeh5JIK9pz2+etco3AfLCKtaRVysjvpysukmWMTrx8QnI5Nn5MOlJj 1Ov4/50JY9pXzgIDVSrgy6LYSMc4vKZ3QfCY7ipLRORyalFDF3j5AGCMRENJjHPD6O7bl3Xo 4DzMID+8eucbXxKiNEbs21IqBZbbKdY1GkcEGTE7AnkA3Y6YB7I/j9mQ3hCgm5muJuhM/2Fr OPsw5tV/LmQ5GXH0JQ/TZXWygyRFyyI2FqNTx4WHqUn3yFj8rwTAU1tluRUYyeLy0ayUlKBH ybj0N71vWO936MqP6haFERzuPAIpxj2ezwu0xb1GjTk4ynna6h5GjnKgdfOWoRtoWndMZxbA z5cecg== Message-ID: Date: Fri, 29 Jun 2018 10:16:56 -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: <20180627013116.12411-5-bhe@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > + /* The numner of present sections stored in nr_present_sections ^ "number", please. This comment needs CodingStyle love. > + * are kept the same since mem sections are marked as present in ^ s/are/is/ This sentence is really odd to me. What is the point? Just that we are not making sections present? Could we just say that instead of referring to functions and variable names? > + * memory_present(). In this for loop, we need check which sections > + * failed to allocate memmap or usemap, then clear its > + * ->section_mem_map accordingly. Rather than referring to the for loop, how about we actually comment the code that is doing this operation? > During this process, we need This is missing a "to": "we need _to_ increase". > + * increase 'nr_consumed_maps' whether its allocation of memmap > + * or usemap failed or not, so that after we handle the i-th > + * memory section, can get memmap and usemap of (i+1)-th section > + * correctly. */ This makes no sense to me. Why are we incrementing 'nr_consumed_maps' when we do not consume one? You say that we increment it so that things will work, but not how or why it makes things work. I'm confused.