From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6847B194137 for ; Thu, 16 Oct 2025 03:13:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=192.198.163.11 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760584424; cv=fail; b=RGqhG87oXvYpO3kLVfX2J6dp7MM1+tlhVRyXruNyfwnUftCrgNLV0u/G/WD48K8N74YlMG4AkKa6dJm/Btk6OL2iih24inHqf4tHIsXOiPiPK6dO6PLo8qQ6NTuXww2sKCaFAYEFa8h8xuOlKG9RXCOiobgkWszvGQHR+kVl7kA= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760584424; c=relaxed/simple; bh=RtOVswzaU81HOkTaqmKlijNIkPfvLz42I/x7xFqBD38=; h=Message-ID:Date:Subject:To:CC:References:From:In-Reply-To: Content-Type:MIME-Version; b=ZDySA7SFUI0eqgA9O6atByCaKL8UC60WykakWbd4xw+CXakbskn09b3Bewi/RD1HkW//er8G5xs3Miws3JWMvHZzs/4/6mbo98+moRnVU9hAW6au3sSYJ92loXDa/04geVKuXA1mu2lhm93MCz+N1MiY7R15D7gPzhk1hL/Ce8g= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=gnPyGYmq; arc=fail smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="gnPyGYmq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1760584422; x=1792120422; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=RtOVswzaU81HOkTaqmKlijNIkPfvLz42I/x7xFqBD38=; b=gnPyGYmqkfPNlzDIsUwgru4oMk6ywHUkGAQ+ZSO0wF51/EMpX8bIsjfw 9zPOoGg+lyBdMeQ4KX2B+qZFNWaiOoP6V9j0MQeUVx6fMzN+s1cudVn0i QFaXyy1PirRiXPORA0NLcOUkgMgo9QXRbQontjfw+fSbdftujy6fDbPVT uHKbFO9cv/x5IAp/iiHZKBDCxd8GILJcVgRvnjvkr8P7xp9YhRU6yHgjG VnyoqS6lvhaKShTb1f/rdpe729gNYs/bJHm69Iv2PMwt2FfhA+J1iPmIp Eu/rWOTyLWwJdrAPsuXAupl5sduhOAu+B68VFa4/FCYfwXOEFmePncqBv Q==; X-CSE-ConnectionGUID: 1SoSzQ8JRAGvPuitsUgjcg== X-CSE-MsgGUID: HGSQ9/D9QIy4T6L3GW2oQA== X-IronPort-AV: E=McAfee;i="6800,10657,11583"; a="73370840" X-IronPort-AV: E=Sophos;i="6.19,232,1754982000"; d="scan'208";a="73370840" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Oct 2025 20:13:41 -0700 X-CSE-ConnectionGUID: tTTaBSDURpGY3ZHV7dwIMw== X-CSE-MsgGUID: dRsg5A2+Rj6VJfAEKGcDsg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,232,1754982000"; d="scan'208";a="182741777" Received: from fmsmsx903.amr.corp.intel.com ([10.18.126.92]) by fmviesa008.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Oct 2025 20:13:41 -0700 Received: from FMSMSX903.amr.corp.intel.com (10.18.126.92) by fmsmsx903.amr.corp.intel.com (10.18.126.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27; Wed, 15 Oct 2025 20:13:41 -0700 Received: from fmsedg902.ED.cps.intel.com (10.1.192.144) by FMSMSX903.amr.corp.intel.com (10.18.126.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27 via Frontend Transport; Wed, 15 Oct 2025 20:13:41 -0700 Received: from SN4PR0501CU005.outbound.protection.outlook.com (40.93.194.18) by edgegateway.intel.com (192.55.55.82) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27; Wed, 15 Oct 2025 20:13:40 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=B8pHqEfQU3EqWetDhi3LSn5y8/ZjLVInxtGnXZI+MJRtSiX3HDvxwH+xnYFyiJsHxnVufMw7798FYpViwpnKZREBu+NLvZAUxj5dgO7laJ+SfM40orw/6Y+WKIeevaP9ftZFJTB0AkY7euCqgKhU9Hh1cdeZW6/I+IaS0LlgeQeqekgaf3+6bDeSqxaAInNcD9qix0AcRG6QoETR5BDLA2VBWPOe+MWgQtnSnSmaYYkTwZE+c0IuFVTYzzrJgJPN8EXHoaGxMxcqD8K56OSXzXDPD9p5tkrgNi3NoAufCNku/DB0dTntCDTl0OQ9zi5hHGQbrxjh+auQ+00PtRgtOQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=+EPISyRTK7anOdmPsyn417lnYVdYmwPDs1bo4OKs3Ck=; b=uu2FjdWV5wdjTLkC7uy0wQGYP1leunuV4qw7or46QqRBNJbEQl9a6WngjGm+4rD/0U5D8JOaP6qEihV8QAJ11RPif2LP/OXlAiAgJeEwRuX5B5HMyhBD2IoqOYXfPYXV9P7DOOA6rDjLeQSFCMs2Gn0T2ig6twjXJbLLMOTjwmc2XEpba891aHQAhORfuY33kwqBh5IxQLLhTEb3TW4MZx/WnkBbXb/Ye1R2dVKHnCD4DbETm0o/pkz2jm0awPs8xpkGdwkQvY6sTVTArh/cS2sQP/6BorSampKyM5c25DnJfjRfwzYrUbivUJvzgwgTP1Lh2ucPbL4vVZFtS5pGfQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from DM4PR11MB6020.namprd11.prod.outlook.com (2603:10b6:8:61::19) by PH7PR11MB5958.namprd11.prod.outlook.com (2603:10b6:510:1e1::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9228.11; Thu, 16 Oct 2025 03:13:39 +0000 Received: from DM4PR11MB6020.namprd11.prod.outlook.com ([fe80::4af6:d44e:b6b0:fdce]) by DM4PR11MB6020.namprd11.prod.outlook.com ([fe80::4af6:d44e:b6b0:fdce%5]) with mapi id 15.20.9228.010; Thu, 16 Oct 2025 03:13:38 +0000 Message-ID: <2e7efcfc-9a70-4e26-9559-e5a367ba8ef7@intel.com> Date: Thu, 16 Oct 2025 11:13:22 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 06/19] sched/fair: Assign preferred LLC ID to processes To: Peter Zijlstra CC: Tim Chen , Ingo Molnar , "K Prateek Nayak" , "Gautham R . Shenoy" , Vern Hao , Vincent Guittot , Juri Lelli , "Dietmar Eggemann" , Steven Rostedt , Ben Segall , Mel Gorman , "Valentin Schneider" , Madadi Vineeth Reddy , Hillf Danton , Shrikanth Hegde , Jianyong Wu , Yangyu Chen , Tingyin Duan , Len Brown , Aubrey Li , Zhao Liu , Chen Yu , Libo Chen , Adam Li , Tim Chen , References: <3df5a8c1-7074-4fcf-adf8-d39137314fd6@intel.com> <20251015111542.GQ3289052@noisy.programming.kicks-ass.net> Content-Language: en-US From: "Chen, Yu C" In-Reply-To: <20251015111542.GQ3289052@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: KUZPR01CA0004.apcprd01.prod.exchangelabs.com (2603:1096:d10:34::17) To DM4PR11MB6020.namprd11.prod.outlook.com (2603:10b6:8:61::19) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM4PR11MB6020:EE_|PH7PR11MB5958:EE_ X-MS-Office365-Filtering-Correlation-Id: 445517a5-5de8-4bde-f85e-08de0c62007a X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?dDNoYlNxV29POGJSdzc4ZWdWTjJIU0lsdExZY0lqb3BKZWZHZk1YU01nZ3pJ?= =?utf-8?B?RDR5MU1OMkhDWkpkUUpPaUhFWkdtR2MzMnZFaWNwVm9BWHEzbllJTWk1WUY4?= =?utf-8?B?UUs1MGRRZDh0aTZGelBBd1lxV1FDOWhqMi9kMmtQMFFzZmxGbEtpN2tIaXQ2?= =?utf-8?B?cVlMNWRBemdjV0JMZk5aS202VG54OWRLbDlQSGIwUW9TS1oyamN4WEtkekp3?= =?utf-8?B?RGFGcm5uSlFjSjBoNXRGVzdOWXdlUGNYYTdwNFdyVWIwTlNIa3RvaUoxdzQ1?= =?utf-8?B?TmZoMlV4aHFCTkJFMkk1QmJBVDRqRjlWeXZaSFN0M3psM1RLc2dSRDQrZkh6?= =?utf-8?B?M3d0MWJwaTRHREJPbHgreHQ5NmNZOFJmQW9wRUVvK1dzWlNIenRob2RuTDU2?= =?utf-8?B?R2o3Q0pmeHN4bFpkUUNObVZWUDRITVozQi96Z0Npc3dFb2d5czRLdGxFSHEw?= =?utf-8?B?bGhCWm01UU5UVmltVEUwdFhPb3EveTVNUHM5OXlFdXdzTFdQVDVYa0gwT29a?= =?utf-8?B?WWtFbWkwUjhlWDI2WU9IMVhXMnVtd25NZ1ZJbG1maHZzUStoQUpIaU1IdklN?= =?utf-8?B?NnpWN2Y5b0huZjFYRlNxOU9OcGoyWkk5b2lpZVhib0VjQjNZbHFEK1l3VTNx?= =?utf-8?B?SjBTekJSWEJZeG9veDZpLzFQWlNzUDRiWWhEdkREMzdSdnZGWGxGY2tnendU?= =?utf-8?B?UGdieEc5MktaT2dZQjliZ1lKM1FkbW5LU3VVU3A5RzEwblFUTGJoWUJYbnl5?= =?utf-8?B?dk5CMGxCTk5haHdFVkNQVjBjM1U1VlpUbE9XQ2pXelk0SERYTllnQzJ4RGxJ?= =?utf-8?B?cEhJNy9HRTV6cjdqNHo4VVlBYWhXSXgxbm9heXAyYzY2aG5rN1FkYnI1dXFB?= =?utf-8?B?L0pLRUpVdTBmTjNzVlJUYWxrK29raU1LVWs3NUtxQStoOHVWRTBWeHNqb3kx?= =?utf-8?B?ZEE2QWhoWU9OdHAxUWVYZGRDSzhZQ3g1RU45ZXl5RDUzYmI0c1ZsNjVWc3pw?= =?utf-8?B?YlNxRXRtYVRQcDkwNkRHUmRvZXJTUnpCZFFqTkgwNU1zMHdFeVVjZ0tVM3Np?= =?utf-8?B?NjlYc1ovaVZnMDl1ZkpRM0RMMDJYTW1kMTBMSXRwU2cyRUlHS2xCb3NxcE1S?= =?utf-8?B?dnpsMTA3akNFTTlwS0VpMC9TcERnaHpoNm5kNUptUk1qYUpGbnZMcjUyWGZj?= =?utf-8?B?VTdiUjhOWHNJUTVxL3U0aTJmOHhJVm0zQm1IRndmYXRsWHFHZFk4MWtVWm16?= =?utf-8?B?eGdOaGZjcHpkYnFjYnlRSjNXTVFHdmNqVUd3SkxPRHlaYXhHd0xNYzJZd3Bl?= =?utf-8?B?ejc3TFBQSExkdkNHM2NkblM4MTZtSnFTZ1JXdHlDZnFEOURUdDFibkJmbTB5?= =?utf-8?B?cC9tVjRrZEpmMGJOOFFaSnB5NnFCcW5MV1piSnhPOU5laGtVQUhqNEdMWTNU?= =?utf-8?B?Z2dTa0JneEhuWmpOSXZtajcwbHprSUlEY1RCWGpkaEh0MFRLaE5YenJIejAw?= =?utf-8?B?OGYxbklJb0FISWsxRGV6ZjdYUkF1enkvdDhDNVlSbG1YSE9UVGIyQS81TTVi?= =?utf-8?B?VzRzVHd2VXFIVDB6OHJVMTlpUmVyQW4yY0l1aVRJeDZEMUoyYVd0VWRrVmc1?= =?utf-8?B?bDgwVE1QYWx6MCtVdENDWGt1YytYb2g5eHIxQ29PYWMrcjgwWTdyaGJ6V3Ra?= =?utf-8?B?SDUwUk5ibmJSQ3NPV0dXYUxRYUJSY09ubXhJODUyaWwyMFQ5eEMydzRiMVJE?= =?utf-8?B?SEllTE9DWWpwTjZpS0JMWUNZUUpwaFdLdlRhNTJVTVIzSGpIVWdUZmE1MlNa?= =?utf-8?B?M25PRXVYUzU2dG1RZFNOQ2l4M2tMblJiTVFNK2VHdC9uRlRLUnFlZmNEU0Ir?= =?utf-8?B?UTM1VDNndEc5Um8weWRNdi9FVWs2VDdDTWEvUExwVGRDSlR4VmRRbm1KbzMx?= =?utf-8?Q?fuKV6K6q2O2XJgm2bwcZgyJ7GN3cmhS0?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM4PR11MB6020.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(7416014)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?QlYvUGprWHN4VnZ5aUlMUFVjTGt1UmxHdWwxeG1WMTFpSlZqbVpZOVVCcFlw?= =?utf-8?B?T2xCeGpZbDNxUkpoVE51ZzR5eC81S21tczFQbzBLV3pJa2ppejBocys1TVNM?= =?utf-8?B?eGFvWlJ4bFhhSkdYYlU5M0JONG14cEg5WkUxbmtCcWwwQjJEYjhMd291Q2tm?= =?utf-8?B?ZHBTMG44d01TSWM4NWdqcEg5VXJVZ2ZOUC9uWERjcUNxdlpiNFJwYnBIN3d0?= =?utf-8?B?SnphYm9vTHJlUmlqY3BmNGc5UFI5bnJhUG43Q3dMamd0bGZ1aWhMSDhvc1Jh?= =?utf-8?B?QllQbjVlV3hNUFRjWFpKTEJGcS9wVG9jeW94Zmw2NzBxMjEvUzBpZ3J5TjFW?= =?utf-8?B?Q3F6M0RicnBrTXJaWTYydDM5TkVJN29OUy9acFRDeXdzelo2TjF5WkpHenMr?= =?utf-8?B?N0hEVmM1RHk0QXlDQW40MmNLYnBkdWxOTmJ6RXdQV1J4akxrWkVQN0N0TnFN?= =?utf-8?B?UW9ueGlKUjdUMkxnanpKOUkyK3NMU25CdFZ0S0xBUzYzalN6a2lacnNpZ3Fp?= =?utf-8?B?c3kzRTdXcHJ5UE9ZNHd5WkdPd0JGU1lRSXpRZld2aGY4SDhBZFZnamRzTEYz?= =?utf-8?B?R0ViYXN2NzF2REJuWG9ZR2RaWEIvR0kwOWZzMDhVZm1IN2NRcnl3Sm03S053?= =?utf-8?B?L3BwWEdEVVBpNXcrRnNwTTJDQmJMeUtadkxDR09rU1hWbVV0Zk5CeFhPRjd1?= =?utf-8?B?eURHeHdzNVJjMGZ1cTBHdlFYZGl6UkJQak45K3BWb3RSK21SYmNBZzBWL1pa?= =?utf-8?B?SE1CeWZUUHdVU1gwZ1lLWEsvQU55eHY0Z0JGdUI2MDlEdkc3aEswb1dMdy9o?= =?utf-8?B?elZqTUd0aDFoWkczN2pwQnVXRWQydzhtLzllQkhqRXloTEwreDk4bnZEakJP?= =?utf-8?B?c2pERUl4R1dNZVNiSkFqUkUzcHR0T1NQVmozeUFaeEVQcXdxSFc4YkpwWDU1?= =?utf-8?B?Q1ljTlpFU0t3dG85QnoyMG9xd1J0SEVJQzVkREd3Q3JFUHIyZkVwclZSVXd3?= =?utf-8?B?a2JSOVFPSHZHejkzV3dsSi93MEFnbVJiYkFFMFVNT1FIUTlkN1RxVnpsWnZB?= =?utf-8?B?VmRjZHlHODlFYnp5YnplTjNEdndGUjV2S0tQZGs5bGpucFJqRUhVYUJpQkdC?= =?utf-8?B?b3NxN0ZOdHQ3OERwcXJxelBXS3lEOE5iYVNIdXdqNWVKcHBhVjVsRDNRSWRW?= =?utf-8?B?YzlXMHJQV0FnSEFJeXpoWkR6Si9qeExVM0I3RENEcHlLamx3VEFUcWlsN2k2?= =?utf-8?B?T093b1JRdTBxQkxJS2t0Tk5sMzdtWUFubyt2TGhEd0dKaE44bkhmQ0phQSt4?= =?utf-8?B?TndSRmxkRlQwZWM5N2UrK1YreDhoNysyc3FtOXhWdVRTR1I1TEluTjZqcmZD?= =?utf-8?B?dUZUK0xyUk5jemIrcTFZWXhSejQrVjAycHQzd3lHYVp6NlpxYXJEYmR3Y1lS?= =?utf-8?B?aWJGZlN6VHNRRVZuakV0UE9nUThRR1hBM085QVhpMmRCN3NnR2p0UU1PbnRz?= =?utf-8?B?cFdGRlNwOUg4REJUUmRjR1daZ3dDc1JsZ0NRZ3B0YjBmSzNOU3dZUU9pWHMw?= =?utf-8?B?eXlreUJGR3VXT1FZK3RIMm1JRVJpMTBaajE5ZWw2T08zZXJaWjFkV1dMUENm?= =?utf-8?B?bzNadzJmTzBGSnpMWFF4end4bEk0djRRQVhKQ0JnaS94Szk5L3pzdVJ3ckZF?= =?utf-8?B?MmRJSEk3TlhxUWxHU3ZiYW12OFdndEl6YVpjc01seUhXcEpjdVJ3K3djOHB2?= =?utf-8?B?dTdEeDdxckxqc2d5WHc4VFRsb1p4WTRWbVhLd29OMEdJek5BendFL1Bva0g1?= =?utf-8?B?Y0N0Si93NkNaNXo4d1dCN2NsSWRZZGc3aEd5Y3RkM3RnUFNhNnFRTmY1RzJW?= =?utf-8?B?ZWQzYXdhb1o3Z3dYbW1URGdxY3VmK0s5cDF5WVVtZGRaNVRLaVNya0llMFV1?= =?utf-8?B?ODlPS2JyRkJGN05tMDJjby92TmR4RzZ5RE1Rem1qTlB5NVM2dC9mSzBSU25Y?= =?utf-8?B?ZEx5dmNyQlVaY21WdHB6Q2gveDNNMkE5SkRwZlNHOGE1ckozTkVoRzRVZUIz?= =?utf-8?B?QXYrY25neFEvenNrZEM1S3Y1UkNLUExEMEhZeWU4SDdBY3IvMU9qc1lGMVI1?= =?utf-8?Q?8quxtnZ99TXmIUTfZYUv+JZ5O?= X-MS-Exchange-CrossTenant-Network-Message-Id: 445517a5-5de8-4bde-f85e-08de0c62007a X-MS-Exchange-CrossTenant-AuthSource: DM4PR11MB6020.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Oct 2025 03:13:38.9297 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: C7DDRk1TnLXBnQw5frMolKPVOQgvj+Ktbtf5pv5Rii6rstDqyO0TOQb+EVLN53Fa2XCyHIhTICKxBI0GgeSklw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR11MB5958 X-OriginatorOrg: intel.com On 10/15/2025 7:15 PM, Peter Zijlstra wrote: > On Tue, Oct 14, 2025 at 01:16:16PM +0800, Chen, Yu C wrote: > >> The question becomes: how can we figure out the threads that share >> data? Can the kernel detect this, or get the hint from user space? > > This needs the PMU, then you can steer using cache-miss ratios. But then > people will hate us for using counters. > >> Yes, the numa_group in NUMA load balancing indicates >> that several tasks manipulate the same page, which could be an >> indicator. Besides, if task A frequently wakes up task B, does it >> mean A and B have the potential to share data? Furthermore, if >> task A wakes up B via a pipe, it might also indicate that A has >> something to share with B. I just wonder if we can introduce a >> structure to gather this information together. > > The wakeup or pipe relation might be small relative to the working set. > Consider a sharded in memory database, where the query comes in through > the pipe/socket/wakeup. This query is small, but then it needs to go > trawl through its memory to find the answer. > > Something we *could* look at -- later -- is an interface to create > thread groups, such that userspace that is clever enough can communicate > this. But then there is the ago old question, will there be sufficient > users to justify the maintenance of said interface. OK, that could be an enhancement in the future if we encounter more use cases. thanks, Chenyu