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Shutemov" , Miaohe Lin , Linux-MM , mm-commits@vger.kernel.org References: <20210902144820.78957dff93d7bea620d55a89@linux-foundation.org> <20210902215342.RcyFEb0qQ%akpm@linux-foundation.org> From: John Hubbard Message-ID: <5327ba7e-fe70-ed72-b372-254d516fd8ea@nvidia.com> Date: Fri, 3 Sep 2021 10:55:31 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR13CA0232.namprd13.prod.outlook.com (2603:10b6:a03:2c1::27) To BY5PR12MB4130.namprd12.prod.outlook.com (2603:10b6:a03:20b::16) MIME-Version: 1.0 Received: from [10.2.52.41] (216.228.112.22) by SJ0PR13CA0232.namprd13.prod.outlook.com (2603:10b6:a03:2c1::27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4500.4 via Frontend Transport; Fri, 3 Sep 2021 17:55:32 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 78a4b44d-f4c0-4b09-5f33-08d96f040658 X-MS-TrafficTypeDiagnostic: BYAPR12MB3061: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:7691; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?NDdOQ1laNnVMc2F3bmtVM2J4dm5kT2lvUVVtZEJLaGFiNmRoZGxLaFd3SjJN?= =?utf-8?B?UmVPWk5NZ25NUklkd0tLWUl4aUdWTGtKTm1ZTWJ5b21lUXcyNjNyMGNmaHh1?= =?utf-8?B?T2tqcVJ3TElDWlFxbUtYdUUrWHpyeUh0cEtCSU9tRHE2MnhGcW15Y2h0M01j?= =?utf-8?B?TzBHRmRZYWltbE9xcG5rNW02Tm5XQkhHTmx2aHlBb3lGdlkyR3RHMXNML0xv?= =?utf-8?B?bFJpWlQxMkNPM1RtMEJsRmNmSG1kWThESWtZN041YlNwaUNMRFdhaERYZE1P?= =?utf-8?B?RXpUMmNEejRHVi9hekUxdE9vdTFqQklXb3RhbFlIY1hUREorcm9nbEZVL3JJ?= =?utf-8?B?VlpsVW1jVC85bllyZHE2NlJOeldQSjhoYWttVkF4VUhIV2tHc3drbFhzbUJX?= =?utf-8?B?K3N0K05rUGhvSzJTSDlZZ1ZJVDluR1JROXhvNzVNbVhxQ3NXRCthYjVUZEpX?= =?utf-8?B?UUo0dVdTZjQrMzZ3dFh5N1p0ejNvQlA1NWlvMitPS293a2tIWUJCZ3Z3ak1K?= =?utf-8?B?Z0JNK2xOdTdmNTlwZWFTOHNNOVdJYWhvTHdJbk9RN2plNFRsMVZTY0oxb2Iv?= =?utf-8?B?T09ZY08zazNiNzBDOTNQZytkcHdCSDZUcUZ4bzNrdXozMTFVbks3VU0wcGZI?= =?utf-8?B?NnhaUDhKcVA4K2hLSlIzQkFDOXFkV1ZBckRoNWU1TlR1dFdCbzBQSitSd1Bk?= =?utf-8?B?YXFHOW1QM3FZdllvVDZYellkcko1REtwTnVCbngrY2Z3OENvdFVaVm92OVVT?= =?utf-8?B?a0MzcWJwTEtJWnFMZUlXczBMMjB0S1g4dFk4L3VQaW1lQ0VBMzNOOUg5Yk5H?= =?utf-8?B?Uk9laDVoeHZLRnp1NWlkTHpCenMrc3RzUENYR201TGV1eUhuWFFYUHNEWmpN?= =?utf-8?B?WGdUVTdIc00vajVnazdVNVdXd1d1R242ck1Zc1BIRG1aWVVuM0xYTU40V3d1?= =?utf-8?B?SldhVVFHTDZScFpZR0RWT1QzVmpPa3Q5M2llYW45WC9vc291cWpRa095QzIx?= =?utf-8?B?clhxRUkrTUdrc0hYQ1RFbHRXRWlNc3pvZWoxemIrN3h4RTdZMWZKNjhETVNK?= =?utf-8?B?cWZtd2s5MU5MbGpXRk5saFk0NzV5K1FaNTkxVkxScGxOZ1FIajFEMWVlemYr?= =?utf-8?B?cnNHSWdxU1Z2aXpieFozaEV2Q1hpWXRwZUlVeUpuZmhHald6NUh2RmVVclF5?= =?utf-8?B?dC9RUzdGRGFVNStBYko4UkpXMjJNbVdzc3BYTlBkTERCUXJPakhobnVFZmIw?= =?utf-8?B?anIvaC84TkZzenM5blVCS2haYlY5TmVWOVdNOWR4OXlTSmpCdk1GbzdUZCsy?= =?utf-8?B?eHhFTDBkRE9sSDNWSzBld0FGaHpTRkc2VHpMUnNvOWkwUmtQbGpJN3ZOUTZw?= =?utf-8?B?cTlwSGYzb08yblBkWHFvWFdPWHNyOUhXZ3I5MnVOaUtrRStQNk93bitSWkRv?= =?utf-8?B?Q2ptQURlbHFhNG9VSTVCN0J2Q0dFdUZaall6NWpUZnQyTUl4blcwbU9Ub0Zo?= =?utf-8?B?ei9UZW9JWHNoMitGV21MOTlDQUI2Ym5ob1BNeFErWUdhUENiSkkrLzIyMTVq?= =?utf-8?B?QlFaRmpEbjA3Y2hGamNJbUpzayt4TlI5NG9LL0dTcWVTMGtKWkFqNUVrRWhV?= =?utf-8?B?QkQ2NXBnZU5mNG9GZ1hjTWhtdzYxZVRyMjJ3NG00UmQ4K1UxRk5aaUFjaERl?= =?utf-8?B?TnRIcTRFMjRJNVBwY1hyVTdTdDFidnBDWXFreEcvZGNGT2VndW1XalpjZklR?= =?utf-8?Q?80AyQypVy1EFBzB0ioUXa4PvU92Tk6OGCIdmPnw?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 78a4b44d-f4c0-4b09-5f33-08d96f040658 X-MS-Exchange-CrossTenant-AuthSource: BY5PR12MB4130.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Sep 2021 17:55:32.8056 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: y5RHSTqV2YU/Lszmgy+dUxh+ksKTNSUiqmLPuyAX8ZZBV+l5qLqqB79mhj4MOIW2DFSKFKwpemyCm53GQ3/g9g== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR12MB3061 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org On 9/3/21 9:35 AM, Linus Torvalds wrote: > On Thu, Sep 2, 2021 at 2:53 PM Andrew Morton wrote: >> >> + int ret = 1; > .. >> + ret = 0; >> + break; > .. >> + ret = 0; >> + break; > .. >> + return ret; > > Hmm. I think "ret" is unnecessary, and this could just have been > > return addr == end; > > at the end to check that we did it all. > > No? > Yes, definitely. So, to be extra clear even though this is tiny and trivial: this incremental change, on top of the current patch, looks good to me: diff --git a/mm/gup.c b/mm/gup.c index 7a406d79bd2e..74142c621556 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2241,7 +2241,6 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, { int nr_start = *nr; struct dev_pagemap *pgmap = NULL; - int ret = 1; do { struct page *page = pfn_to_page(pfn); @@ -2249,14 +2248,12 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, pgmap = get_dev_pagemap(pfn, pgmap); if (unlikely(!pgmap)) { undo_dev_pagemap(nr, nr_start, flags, pages); - ret = 0; break; } SetPageReferenced(page); pages[*nr] = page; if (unlikely(!try_grab_page(page, flags))) { undo_dev_pagemap(nr, nr_start, flags, pages); - ret = 0; break; } (*nr)++; @@ -2264,7 +2261,7 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, } while (addr += PAGE_SIZE, addr != end); put_dev_pagemap(pgmap); - return ret; + return addr == end; } static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, thanks, -- John Hubbard NVIDIA