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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 46487C19759 for ; Thu, 1 Aug 2019 06:20:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBA1C214DA for ; Thu, 1 Aug 2019 06:20:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729901AbfHAGUx (ORCPT ); Thu, 1 Aug 2019 02:20:53 -0400 Received: from mga02.intel.com ([134.134.136.20]:51986 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728884AbfHAGUx (ORCPT ); Thu, 1 Aug 2019 02:20:53 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Jul 2019 23:20:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,333,1559545200"; d="scan'208";a="184128476" Received: from allen-box.sh.intel.com (HELO [10.239.159.136]) ([10.239.159.136]) by orsmga002.jf.intel.com with ESMTP; 31 Jul 2019 23:20:50 -0700 Cc: baolu.lu@linux.intel.com, David Woodhouse , Joerg Roedel , ashok.raj@intel.com, jacob.jun.pan@intel.com, kevin.tian@intel.com, Robin Murphy , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jacob Pan Subject: Re: [PATCH 1/3] iommu/vt-d: Refactor find_domain() helper To: Christoph Hellwig References: <20190801060156.8564-1-baolu.lu@linux.intel.com> <20190801060156.8564-2-baolu.lu@linux.intel.com> <20190801061021.GA14955@lst.de> From: Lu Baolu Message-ID: <40f3a736-0a96-0491-61ad-0ddf03612d91@linux.intel.com> Date: Thu, 1 Aug 2019 14:20:07 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190801061021.GA14955@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, On 8/1/19 2:10 PM, Christoph Hellwig wrote: > On Thu, Aug 01, 2019 at 02:01:54PM +0800, Lu Baolu wrote: >> + /* No lock here, assumes no domain exit in normal case */ > > s/exit/exists/ ? This comment is just moved from one place to another in this patch. "no domain exit" means "the domain isn't freed". (my understand) > >> + info = dev->archdata.iommu; >> + if (likely(info)) >> + return info->domain; > > But then again the likely would be odd. > Normally there's a domain for a device (default domain or isolation domain for assignment cases). Best regards, Baolu