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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9291FC4332F for ; Wed, 14 Dec 2022 06:38:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237341AbiLNGip (ORCPT ); Wed, 14 Dec 2022 01:38:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229513AbiLNGin (ORCPT ); Wed, 14 Dec 2022 01:38:43 -0500 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AD4826ACF for ; Tue, 13 Dec 2022 22:38:41 -0800 (PST) Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2BDLNnvn032323; Wed, 14 Dec 2022 06:38:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=message-id : date : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding : mime-version; s=corp-2022-7-12; bh=D1KIyuGeObn6JGiB5UJkc5d2p9UhW7EGhCMvOWCsag8=; b=z6R8CEa/fuW9fhlvbr3T7XIs0i0LnNnIwXBBQkC2YPFRvQfuB5yDqQA/Joc6M0OG5M08 sElXq1Jr01lij2Y1po6L8jkySEzao8Tor02jF+SdGjVggHyPWVhWrqQMLZF4UbHxZJR9 80EV6d1ZCbaZZc0uF4XqlZr4+BNfg/nA+pN3DWAr0m3X8FSutdqd7g69c5VS/8KlzBj2 ycvZmvZkdyffESMx7uNCrbjCxGNzkBipxvXGfGotXfZ/cSHCMluNDfhxsVOm8a0m888e vWjSyyaokcetcvQEMX5jH+ZjXGf1a5XJOQN/S7ZkxLdGn+Am+D6kO6HzRlcpFlU1ODLD XQ== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3meyews70p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 14 Dec 2022 06:38:25 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.5/8.17.1.5) with ESMTP id 2BE5wFDF037243; Wed, 14 Dec 2022 06:38:24 GMT Received: from nam11-bn8-obe.outbound.protection.outlook.com (mail-bn8nam11lp2168.outbound.protection.outlook.com [104.47.58.168]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3meyekre0x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 14 Dec 2022 06:38:24 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=N1qMXQAHQ2VxAgkDdMvo1t77gf0AkWvJ8r3u2vA6J+y1DcXdAlp3C/H8aqsbYv3JXgy+9R+QNX28xP3DSh8AaaYg/KVjBYAIhLRDv1Va51Lz5uLgGkF4uBkLHiejEm5kIQ1fyiEvU0W/frUWmhTxVbN0E5tNLMhsOtavIeayffNgcLdeGFU6Ego+hXBVV3vTnSizeWhYLE9KbW0tzHV4hCvXxI5pQzpPNymqcD+krc+z0LUZhucw0KF11af79CIzRnraFxUlt5T4I0D96KZ1A8aKo6gZT5QMX9R/KCtbCU4XUgYDEWHSSv9NNTFWRkwOQsIAnxFfY6i4KvIFs+BZew== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=D1KIyuGeObn6JGiB5UJkc5d2p9UhW7EGhCMvOWCsag8=; b=dyd8cFjS7yoC81s3XkWDbJE6EwIdhxJ7zPVZ3wzcFfcG4gKsoZLXeX8ggnwOeoWo4iai1pSeBP0qCkmIeCf4TKJnX4tzifDTQBPnnThZDVC/g8KKNqVHLIdUnQFCukgFbpnGNgEId+ym8Im97VyztnDLbDu6PfZM7WPGzyk4IXoOBYbi2b3Mlavjs7bQ7/lcSHKXLokIaUjWyEldKmRynC1E555XlWmAgdbHrw4iRY9aAynXppy1eewXg0RDoKWctXs3KxUw71qQV4LXb7Z0z99W80Htl5LR3SaLopwmUsFivSp5dlyQudMCAGVzGcwQ6p8kqKs7Bb/huNlnYeKvDQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=D1KIyuGeObn6JGiB5UJkc5d2p9UhW7EGhCMvOWCsag8=; b=CZl+MSi5zcjtZT5Mbpdc2qGY6f2CblwBK08DXYPwV1J2vlKcysXPOl0HmtnBXrPdIaInK9HPCJf2HRQaIL5345JWOpVGd9+33PN5Q7flMr3vbsezv8atMlv0N6J78dLwhoSlBa/JWjKQ6Qe0tsWmN1vHVGEZ/i3j30RG7hLZ10I= Received: from CH0PR10MB5113.namprd10.prod.outlook.com (2603:10b6:610:c9::8) by MN0PR10MB5982.namprd10.prod.outlook.com (2603:10b6:208:3ca::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5880.19; Wed, 14 Dec 2022 06:38:19 +0000 Received: from CH0PR10MB5113.namprd10.prod.outlook.com ([fe80::51be:1301:5ec3:996f]) by CH0PR10MB5113.namprd10.prod.outlook.com ([fe80::51be:1301:5ec3:996f%4]) with mapi id 15.20.5880.019; Wed, 14 Dec 2022 06:38:19 +0000 Message-ID: Date: Tue, 13 Dec 2022 22:38:15 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.1 Subject: Re: [RFC V2] mm: add the zero case to page[1].compound_nr in set_compound_order Content-Language: en-US To: Mike Kravetz , Nico Pache Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, muchun.song@linux.dev, akpm@linux-foundation.org, willy@infradead.org, gerald.schaefer@linux.ibm.com References: <20221213234505.173468-1-npache@redhat.com> From: Sidhartha Kumar In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR13CA0004.namprd13.prod.outlook.com (2603:10b6:a03:2c0::9) To CH0PR10MB5113.namprd10.prod.outlook.com (2603:10b6:610:c9::8) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH0PR10MB5113:EE_|MN0PR10MB5982:EE_ X-MS-Office365-Filtering-Correlation-Id: 4b2f4338-c3e8-4e42-0e11-08dadd9dc904 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH0PR10MB5113.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(39860400002)(396003)(346002)(136003)(376002)(366004)(451199015)(86362001)(83380400001)(8676002)(66476007)(31696002)(2906002)(110136005)(38100700002)(316002)(66946007)(66556008)(44832011)(5660300002)(8936002)(186003)(26005)(6512007)(41300700001)(53546011)(6486002)(478600001)(6506007)(6666004)(2616005)(4326008)(31686004)(36756003)(43740500002)(45980500001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?RC80bS9SeVZSSG9uZENPaTdaVXZrNEJydStmTlNWR2VIQng5V2liYklxYkFp?= =?utf-8?B?cUZLTm1pdS9lRmJVK2g4OGJJclVzdXAxNFV6UkM2eXZ0T3Fad1A3L05wNWNz?= =?utf-8?B?NStyOUJNbHBMb0NkbEtiTmR3bjlHNTA0NTFkMXNUeVFOZFZaUnVNb0hjaFBU?= =?utf-8?B?RS91LzBhWWQxUmMzLzhKb3ZEN1RERnN6NlV0TE5aLzRiUVNnb3VTc3ZvMFI4?= =?utf-8?B?bVVKY2NhZ1RnRWdRajVRTU1lTFNKN0dFbTQ3NlR1eElzMmNuVXZFOTZwemhL?= =?utf-8?B?eDlSVTBvV2FhcTlub1Z5WG1Fd2pub1JMUGtuVEpnWW5vTjVCWmY2eENhMmwv?= =?utf-8?B?cTJqYi9UYVplbkl1V0taOTNvUk5RZGpTMy9IajZINWY0QVhNNHhNU1BQakJv?= =?utf-8?B?T2NDdm5rK01sbWhla0NjNzVySStNZVdqbjRlS0NZZExiN1lxSC84ZU5VT3hu?= =?utf-8?B?Ujh5RFhRVDFidVZXL2lGOG1NNFBQOU9FNXU5eGQ4RjZwelpRSkltSEdLYTU1?= =?utf-8?B?MDhHYWVVZjIwSmppdFVJZ0RaUEh3NEhUSjlabDRrdk1lTDNjYldsRDRZNHJl?= =?utf-8?B?QkFIcG9FV012YlhtWXFCUnJrd0ViTnhkT0g2WXZORjJaaWRCalcvTVJQc1BC?= =?utf-8?B?TklmOExGektpNDhmdDVLL2UweXBQT2JBWEVhaVJmNjdQM0pTa0hzVUppcTRG?= =?utf-8?B?WllTT0NtVDdhMnJWbU5FRWZzYXp4ZXMybEE5Myt6QXV4dVZCb1RLRzQ0WHdW?= =?utf-8?B?a0U0QkUrWVYwZzBnd0w4NEQyU0M4dmxDa29hcFJNTVBQZnRBOHM0WFlrNDJZ?= =?utf-8?B?cXFuMVY2NDRJMGN0MDFuejQ4bTgwL1VXZHlHMVo5TFBzekxsVzZGVGJWZFdk?= =?utf-8?B?bm16T25YMkl3V1F5SlZsWHh2OFdjQTZjZU5vOWhERDJIOTdXUldsR1h3Sit1?= =?utf-8?B?WlFQRk1wWEttc3hDcVVsdHhnT05VeGRheHdaa000ZlhsdVFaM1RMMEk3ZGFu?= =?utf-8?B?ZGJ1MEt1c2o2TnNvaW9PQTBjNmNtMy96LzU3S2tXOUJDMVF1QnpZUmNUZU5s?= =?utf-8?B?UlVjWlNUNDhzMGZtZFFTU21PT3VYWE91bm1GdHZDNDIxU2VrWE0xaHkvL21E?= =?utf-8?B?MlZaMC8zZTVZNHJYWGJBcTlXYmF5MjB5ckdiWlB4Y2pobHBBSCtsOXoxQzRT?= =?utf-8?B?c3ZoWTBJQzVuUjhhLzg4OXdnQk1BMXozT2loWFNBMjRDcExtV3BML0pOalJt?= =?utf-8?B?c2RVamhFQm12enk3eHpEQjlNOE4xUjgyd09DWWF5OWZsVi95N0tRTy9DSlV2?= =?utf-8?B?eDlsMG5SSmpkNTM4QlRtOHl0bS9WOEtRa2NYeUE3OS9zelo1bmFRQmJYVjlz?= =?utf-8?B?Wnc4TDJLTWo5c2JSZWNtbUk4RFNaemZpdkNkcGZxb3RqVTIyQW9FazBCVm5L?= =?utf-8?B?b2o0cWJXR0ovcnR3dzZFWUF6Y3lrNkk4QkF1MzFsQUFsVTRtQzI5bnZkV0V1?= =?utf-8?B?cnliMTQ0YU5VaXJibklCeWQ5K0VBbkc0YVg2cXpNMjZyMTNtSkZLNTYrZ0Nv?= =?utf-8?B?RmlIditkNjVmakdRRVhDTUFia0UxN2o5UzY3K08yeURJSmZ3VVg3M1RrenhK?= =?utf-8?B?ZEhzNDBzdHVhSnJwa2J6a3FvbXorenIxWHRsOVByQzRUWTYvcjdZNFV3MnlP?= =?utf-8?B?QTJQMXIza3ZQQUJxOUJkamN4VnQzVjVWaE1DakRvL2UrcHV3Q0RaUC9Ua3A0?= =?utf-8?B?blJoL3JvTURqdG5IeG1ObVhYSFlTdE50T1A3UzlWSW80M0diM2c1US9CclVH?= =?utf-8?B?aDVsRnkyQWpKVm9ISlcwQ1R3U1FtU3p0dVdmd3hWVDFNc3gyUmFTVHJnSlRj?= =?utf-8?B?b0pZNUdQbnZid0toRDZqZFpWNDhQVjVFaDE0WTNDLzQrYTdMdk1wNmtXM0lF?= =?utf-8?B?a1RHSmFucEdXVzJMaE9ZQUJmSVVLOWRqN0dvUWxLbHZFdStJcGwvL3FYSEVp?= =?utf-8?B?Um5YV01tNXJrTC9VS3RnU1U2dlFtL3d0QktCc243Ym9iVFdxVUw5YlYyZFpT?= =?utf-8?B?b0dhdmx6Mzd1OEQ4d2d3YXQvS3hJSVYwSGpLOUdQbDlXdGRoUWlXcmJQcGRr?= =?utf-8?B?SGJqNk9XU0hkVWJvSjVXM1l3SUwwMHg5cmVRTlVnd0FpM1BVWEY0OG1MRFRp?= =?utf-8?B?RHc9PQ==?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4b2f4338-c3e8-4e42-0e11-08dadd9dc904 X-MS-Exchange-CrossTenant-AuthSource: CH0PR10MB5113.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Dec 2022 06:38:19.6862 (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: FXqFVqVoS+4RjsVjT6fusXe5ajUmlJQKhXpzfNLx1Xd3Jwivl3BAo0dda7Aupw4x1Vv5lLEZIG+ly6taoKEQzZA7Z4jw0z6+91INoxHWeyM= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN0PR10MB5982 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-12-14_02,2022-12-13_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 malwarescore=0 phishscore=0 mlxlogscore=999 suspectscore=0 spamscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2212140050 X-Proofpoint-GUID: VYYxN1iU3wI9zCJw5vSWbkRfmKa8ypML X-Proofpoint-ORIG-GUID: VYYxN1iU3wI9zCJw5vSWbkRfmKa8ypML Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/13/22 5:02 PM, Mike Kravetz wrote: > On 12/13/22 17:27, Nico Pache wrote: >> According to the document linked the following approach is even faster >> than the one I used due to CPU parallelization: > > I do not think we are very concerned with speed here. This routine is being > called in the creation of compound pages, and in the case of hugetlb the > tear down of gigantic pages. In general, creation and tear down of gigantic > pages happens infrequently. Usually only at system/application startup and > system/application shutdown. > Hi Nico, I wrote a bpftrace script to track the time spent in __prep_compound_gigantic_folio both with and without the branch in folio_set_order() and resulting histogram was the same for both versions. This is probably because the for loop through every base page has a much higher overhead than the singular call to folio_set_order(). I am not sure what the performance difference for THP would be. @prep_nsecs: [1M, 2M) 50|@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| Below is the script. Thanks, Sidhartha Kumar k:__prep_compound_gigantic_folio { @prep_start[pid] = nsecs; } kr:__prep_compound_gigantic_folio { @prep_nsecs = hist((nsecs - @prep_start[pid])); delete(@prep_start[pid]); } > I think the only case where we 'might' be concerned with speed is in the > creation of compound pages for THP. Do note that this code path is > still using set_compound_order as it has not been converted to folios.