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Thu, 12 Aug 2021 18:19:02 +0000 Received: from [10.2.53.40] (172.20.187.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 12 Aug 2021 18:19:01 +0000 Subject: Re: [PATCH v2 3/3] mm/gup: Remove try_get_page(), call try_get_compound_head() directly To: Christoph Hellwig CC: Andrew Morton , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , LKML , , , , Matthew Wilcox References: <20210811070542.3403116-1-jhubbard@nvidia.com> <20210811070542.3403116-4-jhubbard@nvidia.com> <20210812092204.GB4827@lst.de> From: John Hubbard Message-ID: <5bf6d220-1126-97a6-c7cc-3c198612c5c2@nvidia.com> Date: Thu, 12 Aug 2021 11:19:01 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <20210812092204.GB4827@lst.de> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [172.20.187.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) To HQMAIL107.nvidia.com (172.20.187.13) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 301ff135-5351-4b57-abe9-08d95dbda9b3 X-MS-TrafficTypeDiagnostic: CY4PR12MB1448: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:2582; 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X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Aug 2021 18:19:02.4333 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 301ff135-5351-4b57-abe9-08d95dbda9b3 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.112.34];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT058.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR12MB1448 X-Rspamd-Queue-Id: A630F8022775 Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=WjpZylqR; spf=none (imf06.hostedemail.com: domain of jhubbard@nvidia.com has no SPF policy when checking 40.107.96.55) smtp.mailfrom=jhubbard@nvidia.com; dmarc=pass (policy=quarantine) header.from=nvidia.com X-Rspamd-Server: rspam01 X-Stat-Signature: ysr6m774xhjipjj5t1pmhrhbzt4cx9tr X-HE-Tag: 1628792344-90898 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: On 8/12/21 2:22 AM, Christoph Hellwig wrote: > On Wed, Aug 11, 2021 at 12:05:42AM -0700, John Hubbard wrote: >> - if (unlikely(!try_get_page(page))) >> + if (unlikely(try_get_compound_head(page, 1) == NULL)) > > Why not a simple ! instead of the == NULL? I'll fix those up and post a v4. > > Otherwise looks good: > > Reviewed-by: Christoph Hellwig > Thanks for the reviews! thanks, -- John Hubbard NVIDIA