Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <b0a1b637-cad6-9458-53ab-4f54c2b808c9@oracle.com>
Date:   Fri, 9 Jun 2023 13:18:59 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: [PATCH 1/2] mm/filemap: remove hugetlb special casing in
 filemap.c
Content-Language: en-US
To:     Matthew Wilcox <willy@infradead.org>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        akpm@linux-foundation.org, songmuchun@bytedance.com,
        mike.kravetz@oracle.com, david@redhat.com, nphamcs@gmail.com,
        jthoughton@google.com
References: <20230609194947.37196-1-sidhartha.kumar@oracle.com>
 <20230609194947.37196-2-sidhartha.kumar@oracle.com>
 <ZIOF7pu0hvab7HYa@casper.infradead.org>
From:   Sidhartha Kumar <sidhartha.kumar@oracle.com>
In-Reply-To: <ZIOF7pu0hvab7HYa@casper.infradead.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?dytPNTZJMVQ5UE9ublRZZ3gwRjJQTlpzcFNMdWkxYlY3eXBCeENrTUN1OHRU?=
 =?utf-8?B?QzBvSkZvNUZqN05kdGNIZlBrZjMxMkdPOTVKb25aVEFsMWFlV1ZDczVzbjlR?=
 =?utf-8?B?OUpxdGREazR2RElRYWdKVEdNWjJuSEpsOGMyL0RJSHJqRWNCQ1l0TVgxdW9N?=
 =?utf-8?B?L0VpeTdLcWxLNjQ5WFJtY2lvMmZCaEVjcmFCQ0drQ2l5R0d2K0RnZjQ5dWFI?=
 =?utf-8?B?MnQzenlTRUlrV20vektmUFpkb2wxT25TZHFoWlpwRzJxd1R3dXgrUThKSjBu?=
 =?utf-8?B?Z0hYdTBGOU1xdys2SjNlY1R6VXZ0WDJUTkpOTG81Slk5WFRVT0Z5M0tTb29P?=
 =?utf-8?B?QVNrYVVwbVVvQWw5d0lDT3dFR1RHMm1KQVpKRnUwTXZCV2pTbjdib0tmTXpr?=
 =?utf-8?B?L1k5bUFXeGovOWJCdTBPL1EwMFB3bFJ2dVl2N0Y3WDlxTHdmTENOTTdqTU5O?=
 =?utf-8?B?OG5KZ3plR2U2bnNPSW5ZdjZhWHpWaVBJU3JvR3RXMVN4c1ZOY0NiMjVYMjFT?=
 =?utf-8?B?ZGVhMyttWHhWc2kreDlROGZvT2FJWmJwUkFiTzMxaXhOVG5qZUFCODM1L051?=
 =?utf-8?B?aVFiT3ZtUjlrZzBjdndBUFBiMlRRdGNET3VVU3oxUjFVMU96Z01tb0c0YThE?=
 =?utf-8?B?WVVRZFBxWDRlY3lqamE0eld4ZU9TNlI0K1cwZ3JnYWVEa3lNWVp6T3FzeVc4?=
 =?utf-8?B?RkxGbTZlUnNYeExSM2pLUnVGVzBLT2FOZ3I0ZUhpNk5SMFliZ0p5bVZUc05H?=
 =?utf-8?B?OEhFRDNoRk5kVE1BaUxJTEg4akd0aGNEYW1RQ3Y2NTNIMUFjSHhBMVBDVzk5?=
 =?utf-8?B?M0FoOWUzSzllOXVZYkc2a3J0YmZhR2gyR2JoWlhLb09NTno2WXgrNXRwYjEr?=
 =?utf-8?B?b21GK2xmbnpyOVV1emY4K25aT3Z4ZHZiNDVCMWRrcDVvRktyR0ZxaUovaVBh?=
 =?utf-8?B?VHNLQmN5cno3K29qc0d0a2d1bHZBVC8zZHFheDZFVXdhOUQrdzN2UXZ0M0R1?=
 =?utf-8?B?a2FveE91bk5ScGRmM2QzVlp1NXdqTWpCWEpUNDQ5MGdLZGVjVm9wdnliSGFp?=
 =?utf-8?B?WitaY1N3QmlrZ2QzcWMzbDJ0bCtNdjg1UmRjTm1Yck9KaTMvaGMyVSthL1hu?=
 =?utf-8?B?aEZlT2dUYUVNTFJLZXBESFBCUXlkaEQwMzRwWEJwSmRJZFJXTlNja2JtbnYr?=
 =?utf-8?B?SFJxZ2lGY2RFOHJoUmh0ZE00ODl0WWYrVzFUNlI5SVVPL3VmWlRHbkhYYTBZ?=
 =?utf-8?B?a0NKd0hhMUlsdlFjS2c3elY2OFlxUXJxZHZROEFLSnVyUzYyLzlOb1lvenNh?=
 =?utf-8?B?V0IxYUYyUVNJaDRQaEljMGZRa1dIYjVlZTNlUDliakwyTGlUd3ZwZzVPUkxJ?=
 =?utf-8?B?MkxxaUhTdTJwczRzSk1VNExuaUNmb3JqVlZKc0FMRzJqYkFGNlFoRndDaU5s?=
 =?utf-8?B?UHVucUVHTk5pcjJNWmUyRDRhQlA1ZzhBdmFwTFRSWXAyd1lMcko5VkU1QjRK?=
 =?utf-8?B?RHYzaENGV2U4cTBCOVBIazVnSTRvN1l5STRTNHQ2QVgyODUrZlYrTDdLMVBY?=
 =?utf-8?B?L1M4U3V0KzAzTi8xcWtKcW9lVGpZMEFrSE12cEdIUy9kYnZEN2h1K3kvdEJI?=
 =?utf-8?B?THdyM3hNaEpaSWdNbHU3SHkxNzk4eGlyd1U2WTJTbGdFOUt1TEF2aWs1RFNX?=
 =?utf-8?B?SDlRWkRrbnV1dmpYZ1RtWDlPeHFGU28zd2s5czVIcGdrLzZ5S3hkemJVTnkr?=
 =?utf-8?B?dlZySzNIakZld2NOU2hWbFFwVXpBZ0tVMjZJY3ZEOXJjdGxpdGVvbXlUeWs1?=
 =?utf-8?B?V216NWplcG5RdTdDOFdsdkZ6eVFvMWIxRldiMkFhLzVoV29ZdWhjdll1Ny9n?=
 =?utf-8?B?d1I2dDVLZytTbFJ2TjFGZGg5SnhmTUYva3JCWmpHYjVSRm55cUdaZXJpWHNV?=
 =?utf-8?B?bUVlU0l3RGF3T1JsMGpueUltdHhMZnBvNWs0ZkVIR2NiTzVwUDlEUmlrK2k5?=
 =?utf-8?B?eGIzazFFdklCcjZwdlN0NWdZVnhaRERCQ2lyYlI1YnNWNjMxdzNpUmlqd1l3?=
 =?utf-8?B?clhVckQwK1IzUXlpS2JqN2NRUnpORlQ5RGdiQXErTmhYSFAraUlDZGI0VDFO?=
 =?utf-8?B?NmRHeENLcUgrcjNmU2phQ0ZIYkZYRTg4T3dsVTM5c2U1S2g3OW5LOUo3ditn?=
 =?utf-8?Q?cNO4zKpkCutWGA8A24/5H84=3D?=
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: =?utf-8?B?dC9GMUZMM3VYT01JWXVYOW1JS283cmhKVEIwRm1RcE1ySE53TTNqWXhMUzRV?=
 =?utf-8?B?T3ZLUHZNb0djT0d0VEJkQUNsVzFhZ1oxSml1RXJOOHNYcGZGM2VwUFFrbmZ5?=
 =?utf-8?B?Q1dQOG4vUG9WaWFhWkRtMFZIT2dZd3UxSk41K3ZXaUZNdXE5Yzd6VEpDbzhl?=
 =?utf-8?B?dUNsME83ckRLODMzZXBtMlFsT0ZwTzNTb1pIeGpCSlFsRUs2TE1GVkFvVVNX?=
 =?utf-8?B?TkZka0Fud3NkVUY4VTJSNnY4eTRDclB1aWx1QW9ES3RNM0gvK3hqZ0Fod1hO?=
 =?utf-8?B?OFA0bnh3a09jQ2FSb0sxUHNWZkVmNjlJczVxRUxKNDBSL1c3WTlSZG1SUXJv?=
 =?utf-8?B?a2hwaElGS2syRkxRT3BuNU5pQmNRQ3IrUGRveHhwQWlzWTlDVllOc0kwblNW?=
 =?utf-8?B?aUpsZmhCUjh6MWhlcm9tT2RnVjRYa3V5YTE5bXhOcmtRaTllVWRvRDRFdXFB?=
 =?utf-8?B?c0w3SkRnQW5kNWFMdWMzWU1pU09EZ3RIUGpmcUE1K09IbEtjOFNwa0RReE1k?=
 =?utf-8?B?TTc5UmJlQUxzNnRueEY3eWhMYWtQQkhDOUpjR2VVZzl2aExqZ0pqVzhyQlA2?=
 =?utf-8?B?UjZzWGtUc2p5eW8xRDFWVVlJM0Vnbnl0ME9lQXNoTUhieW0vM3dTSzZpNFZk?=
 =?utf-8?B?bHVxYVk1bXdlREJ6MWkycHlUb3pPd3BFRWxDZEU3ZGVROUpJN3htRXpQT21Z?=
 =?utf-8?B?cWdmNUNoTWpMOEIxcTFFaFVXSi9WWHlxV2pKTXRxWW9OZk9jaWh0c01YM2hj?=
 =?utf-8?B?Y2xnUzFTamhZUDV3eExIbzFQOCtZNnNLS0VoQzVDcmwybG1GdUU1UEVEVFVm?=
 =?utf-8?B?YTU2Y29UbmEreG1Wc2F1UjJMYWw5MGlNV1NsVWJlOGlEOXBhUWRsczhhdHRP?=
 =?utf-8?B?b0diWEl0Nzg1YlRIaGhuYjVkSG8zS1FTVW9DbnlhN2RJRDhYVmxGcVIyYkNK?=
 =?utf-8?B?Yzg1TmFXVWhwWmxjY0RJVTJHM3JCZFVBaGRDSHZpb05VWHRCRHozV0xUUyt6?=
 =?utf-8?B?OVNkL1M5VkMwK1dESG1GVTVlS1Z4RFd4UzlyeCtqU0RpaEwwK0NqdzQ4bEp5?=
 =?utf-8?B?NHB4MWh3cDYvYXltMTFIdC9rS0QxOHFLWG1xczR3U3d2K2I2T2FYQk82RmlG?=
 =?utf-8?B?NDlscEFRVktBT2k5Ym5IM0pqK1lDbmRWcUNscThpS1lvODlDRU0rUE1Camgw?=
 =?utf-8?B?Ri9ZbEtCYTZBdkROZHZEUDRPRWFVSE9RdS9NTzFiUG1oUCtKT21qT1ppMTlN?=
 =?utf-8?B?Z0pGb01rYytIQ2JUODA4bXU4bnpxckZaUzA4WFBrYnU1Yzd4R3AyZWZqVHFl?=
 =?utf-8?Q?9uz0uq1L2SauyxFWXmCcPYH6GbiXkX7W44?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 39a0336f-ef33-4d9b-729f-08db6926c421
X-MS-Exchange-CrossTenant-AuthSource: CH0PR10MB5113.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Jun 2023 20:19:02.5072
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: VvJ437l4pxShofsU1SsQIjqehF7+vd6QfVziYK8ZuTQ/Zt5m8GwMx1CrCHFnSlp+m9WSchG/XnDvKJWcbat27f9ENKmWPl+7DolvSfuCmJU=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR10MB6798
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26
 definitions=2023-06-09_15,2023-06-09_01,2023-05-22_02
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999
 malwarescore=0 bulkscore=0 adultscore=0 mlxscore=0 spamscore=0
 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2305260000 definitions=main-2306090171
X-Proofpoint-ORIG-GUID: uj_NsLQV2NQgyhGD3pKTV0p-LdN_PckX
X-Proofpoint-GUID: uj_NsLQV2NQgyhGD3pKTV0p-LdN_PckX
X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,
        T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 6/9/23 1:05 PM, Matthew Wilcox wrote:
> On Fri, Jun 09, 2023 at 12:49:46PM -0700, Sidhartha Kumar wrote:
>> @@ -850,12 +847,9 @@ static inline loff_t folio_file_pos(struct folio *folio)
>>   
>>   /*
>>    * Get the offset in PAGE_SIZE (even for hugetlb folios).
>> - * (TODO: hugetlb folios should have ->index in PAGE_SIZE)
>>    */
>>   static inline pgoff_t folio_pgoff(struct folio *folio)
>>   {
>> -	if (unlikely(folio_test_hugetlb(folio)))
>> -		return hugetlb_basepage_index(&folio->page);
>>   	return folio->index;
>>   }
>>   
> 
> Unfortunately, you can't split the patches like this.  If somebody's
> running a git bisect for an entirely different problem and lands on the
> boundary between these two patches, they'll have a non-functional kernel
> (at least if they're using hugetlbfs).  So these two patches have to be
> combined.  Maybe there's another way to split up the patches, but I
> don't immediately see it.  Maybe after I read more of them.

While this is under review, should I keep it split so the filemap and
hugetlb parts are separate and easier to review or should I combine 
these two patches together for the v2 immediately?

Thanks