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=-8.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 9E62FC433E0 for ; Tue, 9 Feb 2021 05:19:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 452D264EAA for ; Tue, 9 Feb 2021 05:19:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229742AbhBIFTj (ORCPT ); Tue, 9 Feb 2021 00:19:39 -0500 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:8523 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229472AbhBIFTe (ORCPT ); Tue, 9 Feb 2021 00:19:34 -0500 Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Mon, 08 Feb 2021 21:18:54 -0800 Received: from DRHQMAIL107.nvidia.com (10.27.9.16) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 9 Feb 2021 05:18:53 +0000 Received: from MacBook-Pro-10.local (172.20.145.6) by DRHQMAIL107.nvidia.com (10.27.9.16) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 9 Feb 2021 05:18:53 +0000 Subject: Re: [PATCH v2] mm: cma: support sysfs To: Minchan Kim CC: Andrew Morton , linux-mm , LKML , , , , References: <20210208180142.2765456-1-minchan@kernel.org> <43cd6fc4-5bc5-50ec-0252-ffe09afd68ea@nvidia.com> From: John Hubbard Message-ID: <3cf67381-9b5a-56ee-2a8f-047955c84128@nvidia.com> Date: Mon, 8 Feb 2021 21:18:52 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [172.20.145.6] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To DRHQMAIL107.nvidia.com (10.27.9.16) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1612847934; bh=L8BK9D+uuYU7ZhrW2feVoLIu8IHxKir02v9HrkdcSyQ=; h=Subject:To:CC:References:From:Message-ID:Date:User-Agent: MIME-Version:In-Reply-To:Content-Type:Content-Language: Content-Transfer-Encoding:X-Originating-IP:X-ClientProxiedBy; b=B/QqkRE6/oM+57E2Rs9HLW6n93XxcfSSDlZGkgrlo1H0SYqiAZcLql1cTJG2z1YNU y0p9JTd6Ia8zC303LeT3YE6aC1Co6buUcI2BEgeyMES7sxqH3v5mRqKkzzUxFGkmeH mIgjNftb7E+r3gNe+y4FTqpF5vxPawP1j2IRozglnAgaUrdfHVzFgNE2J456mZnEfY iX/ibQmDHUU4xvvyONbcuof9GEIkEJdBRmNKKwx+ESaM9qQnyCCcwsOEQngdMMkStD KSmhxOoBogx2hhFj6+IRyK/NDI9qsdi1y7U2q/A9Zh7W+qw/fXEU/bd0cc3A9Guhd4 MDnbsAc2EhyeA== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/8/21 8:19 PM, Minchan Kim wrote: > On Mon, Feb 08, 2021 at 05:57:17PM -0800, John Hubbard wrote: >> On 2/8/21 3:36 PM, Minchan Kim wrote: >> ... >>>>> char name[CMA_MAX_NAME]; >>>>> +#ifdef CONFIG_CMA_SYSFS >>>>> + struct cma_stat *stat; >>>> >>>> This should not be a pointer. By making it a pointer, you've added a bunch of pointless >>>> extra code to the implementation. >>> >>> Originally, I went with the object lifetime with struct cma as you >>> suggested to make code simple. However, Greg KH wanted to have >>> release for kobj_type since it is consistent with other kboject >>> handling. >> >> Are you talking about the kobj in your new struct cma_stat? That seems >> like circular logic if so. I'm guessing Greg just wanted kobj methods >> to be used *if* you are dealing with kobjects. That's a narrower point. >> >> I can't imagine that he would have insisted on having additional >> allocations just so that kobj freeing methods could be used. :) > > I have no objection if Greg agree static kobject is okay in this > case. Greg? > What I meant is, no kobject at all in the struct cma_stat member variable. The lifetime of the cma_stat member is the same as the containing struct, so no point in putting a kobject into it. thanks, -- John Hubbard NVIDIA