Received: by 2002:a05:6a10:8c0a:0:0:0:0 with SMTP id go10csp3361005pxb; Tue, 19 Jan 2021 22:54:30 -0800 (PST) X-Google-Smtp-Source: ABdhPJxE5aJsZ5wbzGNGKU56SkT6ffvV6vaVZ/VcOR7I2ukjxUql0+MI3MeCdUjV+fyOwaqvn37A X-Received: by 2002:a17:906:eb95:: with SMTP id mh21mr5421143ejb.175.1611125670540; Tue, 19 Jan 2021 22:54:30 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1611125670; cv=none; d=google.com; s=arc-20160816; b=AEP0upve6r/sk5e+jHYj6dTdIe4BZlgkTvRRU8NorRghaRpsXrLkzGJafkJfZS8X5A JiloVWD8aKjwE49i1gR82yRnVjlun2GHYa1vTSG45ZQKESZNms7s7tnWmyzKDU6sKg0f h/cRJ6KvZxj68cIoxXmdOdelogEQah3XBiSD0Oee3U5sYap7k4Qe/WvjJSUExOizKPnO wuPbCHYdTjVJtevJcmXlaFWOu8SB95dFCXwry93XcBcq9hQp3u87dp/skxvfJLqMDJy0 cAjAxKaKbCB3uskUcAXxwTGUUhd37ShIxDwNSiEs8e6Icltc4vKxfCeOr9e2/0LxMw0j 7bSw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:content-language :in-reply-to:mime-version:user-agent:date:message-id:autocrypt:from :references:cc:to:subject:ironport-sdr:ironport-sdr; bh=2eLKFdqAuyLDTf0uqON3YYSOYnjlAzB5nxj8eaYwLoE=; b=0hcd1lD5+SJDok2y0jhdRN1r8zCCHVBYbrD8PbOPFSNUVWvy7Uo9cb5jAV8OZg8vxG JtdO+HQOenN15OhaPy2JIkPfC4HurSUmDktOaMTAO5JOcTPecmN12jgFyeEUlPIHQhxE Vgu9AO7QWAxdbYRhRSE1sghVFS/eSh/q9vGFhML6h4BtWdkmtavZXdTNKGdjD3n66D/1 wuVRibDWJk9BnowJDWqdzPQb709VgkAxc5Gs6CPE5gUNeg/L44GvcenInKtY++5w8Xdh zH+xjPzUmt7TclBDrsMAh/MShZ7NVeiiNNKPPIVZPRB4kFmG0XXW0ZsQo00msmZm1qXZ wMlg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 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. [23.128.96.18]) by mx.google.com with ESMTP id df24si506874edb.246.2021.01.19.22.54.06; Tue, 19 Jan 2021 22:54:30 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 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 S1726840AbhATGwl (ORCPT + 99 others); Wed, 20 Jan 2021 01:52:41 -0500 Received: from mga03.intel.com ([134.134.136.65]:4747 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726931AbhATGuD (ORCPT ); Wed, 20 Jan 2021 01:50:03 -0500 IronPort-SDR: 5N5drfTyND5/F3pj2qvi1WmspyuQoxfKEdAHSr8PI5+cWe8M82awK86PT0aoJovy8XVAeTyvWJ 8bDck8oWojyg== X-IronPort-AV: E=McAfee;i="6000,8403,9869"; a="179141585" X-IronPort-AV: E=Sophos;i="5.79,360,1602572400"; d="scan'208";a="179141585" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jan 2021 22:49:20 -0800 IronPort-SDR: r+v96fKenyKQFjUQ2j2Z48kO6J16R3wsSK7YVpEAWZU5HKFdthEeCzB0pdD8Q59j3gPoDgFfOx rp5++gEWnEXg== X-IronPort-AV: E=Sophos;i="5.79,360,1602572400"; d="scan'208";a="354222554" Received: from crschrol-desk19.amr.corp.intel.com (HELO [10.251.23.65]) ([10.251.23.65]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jan 2021 22:49:19 -0800 Subject: Re: [PATCH] x86/fpu/xstate: calculate the number by sizeof and offsetof To: Yejune Deng , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, yu-cheng.yu@intel.com, tony.luck@intel.com, fenghua.yu@intel.com, kan.liang@linux.intel.com, viro@zeniv.linux.org.uk Cc: linux-kernel@vger.kernel.org References: <20210120064415.16977-1-yejune.deng@gmail.com> From: Dave Hansen 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: <26c1f5be-7232-3e2b-dcbb-367ff0bbdbb8@intel.com> Date: Tue, 19 Jan 2021 22:49:18 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210120064415.16977-1-yejune.deng@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/19/21 10:44 PM, Yejune Deng wrote: > In fpstate_sanitize_xstate(), use memset and offsetof instead of '= 0', > and use sizeof instead of a constant. What's the benefit to doing this? Saving 4 lines of code? Your suggestions are not obviously wrong at a glance, but they're also not obviously right.