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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 276FBC3ABBF for ; Wed, 7 May 2025 15:12:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CBC866B009B; Wed, 7 May 2025 11:12:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C6C8D6B009C; Wed, 7 May 2025 11:12:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AE6226B009D; Wed, 7 May 2025 11:12:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 899AF6B009B for ; Wed, 7 May 2025 11:12:45 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 1682E5A27F for ; Wed, 7 May 2025 15:12:46 +0000 (UTC) X-FDA: 83416453932.20.A170EAD Received: from NAM11-DM6-obe.outbound.protection.outlook.com (mail-dm6nam11on2055.outbound.protection.outlook.com [40.107.223.55]) by imf17.hostedemail.com (Postfix) with ESMTP id 2751840009 for ; Wed, 7 May 2025 15:12:42 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=sCi5+vuA; spf=pass (imf17.hostedemail.com: domain of ziy@nvidia.com designates 40.107.223.55 as permitted sender) smtp.mailfrom=ziy@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1746630763; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=noSlmrVzHbhntWWQWKhZ3Btrkfo9y0AsHHuKLSJmKEc=; b=LnqrmJZh9DtV1PddH8S7LlvZJP8JsZxRfn8vY07fqmmhX7fmcfQHY1wNWvPLGTgULjbS1l /s+jb5CjM0dRBtZli7UAWW5Z2GVzF/nPnKOzjX1SPAI683oGmTfdcULW63qnVKMAxJELyb i1IoQWBrngGy4mMeCcHJNVkbTqMeEfU= ARC-Authentication-Results: i=2; imf17.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=sCi5+vuA; spf=pass (imf17.hostedemail.com: domain of ziy@nvidia.com designates 40.107.223.55 as permitted sender) smtp.mailfrom=ziy@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1746630763; a=rsa-sha256; cv=pass; b=mWm5XqKsdFvGglfb+eC64lROa1WwicmZZaayt5u5sR6gxK2kAEy15sYoYgnackjWkE/sVb XkJavd+4GDKQXayL2kC4UJgVUiMl5RHRGdb/4NWbhFLUvA8pz7f9hpfJJ+apK68CxFRU5L IyEo+sxlT1j/t2xGfQ7abZwYDD7rfuA= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=o4JIQG/+u+Nx+2USOdXs7u3JIqSZnmcXqmOD2eM+5x1zckxs1SCDO0yy6UCdYjEyZbhdPsVt6XsgU37lBUbFGA0ywPQ+vx/ESqfeZQidfd6p4W3WBd3mwInFn4M6QnYHsVdtBZi9CJXVS+MT7PWWGXfD0hFGmeWsK/zS5I6/dDcdpNGcqcWoZcZQ3saw4ChWxRUyR6HvodnQPIoiXrOr45JnjLySgXwX0QPhPSVyj5mFaMdH40r175juvxuwIVD7C4k7kfjStKEQZdl8UC2hSK4DE4uDrrQrpsYSwjQaneq/G4HFcRHbCBO2sPS++lofgG9biHzcJ5mmJ7Dqp9OTNg== 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=noSlmrVzHbhntWWQWKhZ3Btrkfo9y0AsHHuKLSJmKEc=; b=be0Obno1vP6GV4bYeDZnsh2/NN1OwUk0rnfoL+jjIWKUDNsW+azLsBBhIRdm4tauc0odjG242gyQ6tC8/gfhbogT5GfKYTkqQAdLbqMlGgxwMD08iGccepMqWcDwHQ/FGuHIEFtxshcfBeeFNvvNtWY2dJ4apMutUCZN/Dz7Z2do8LN6in3EFj4pSOn7WSYQm/7I5MX0VxTol71MwDYRdABRja7RUacALhw7xrVryFQzHYrSS86gTLiqKiGijhvDbRjYocLndZeWV/7zJUO94PqjCPMTtHpLPJcksEICyG1/qoCQf3queR5SV4r3cjjWGg3hngN5C+EEHt9FEerstQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=noSlmrVzHbhntWWQWKhZ3Btrkfo9y0AsHHuKLSJmKEc=; b=sCi5+vuAYIfFKDU5R6ywYoiap8FDzNpq77BPSI2IOzB7dhNOMhZXXKty39mCnMJ8TjTCcAiXsB1bS05LF4GKlXE9kyBGv2qmLPFkvacUUZbW0ihUj6DTtuQlCXd06ZKzmIrHnwrqtkyTMZ0fVC8u3TyLP8UbfGsaI/nBUwqDEOIWVXtAVJhb/ANpkWpTaOn7F/wKku9ldmCCJv1ruXY5QkTLNukvrgviIRgVdcSbVswqJ/tfUYnbmbRzKPDnCFUooThXhwBly7fYOF9UdbGr7MN2ENaH8xN3GO3bKgGMwfQfk9IsLvriuaFrp/n9n9vzavGHnmrSLDkrd8fHypWsoA== Received: from DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) by SA0PR12MB4397.namprd12.prod.outlook.com (2603:10b6:806:93::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8699.26; Wed, 7 May 2025 15:12:31 +0000 Received: from DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::5189:ecec:d84a:133a]) by DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::5189:ecec:d84a:133a%5]) with mapi id 15.20.8722.020; Wed, 7 May 2025 15:12:30 +0000 From: Zi Yan To: Nhat Pham , Barry Song <21cnbao@gmail.com> Cc: Harry Yoo , Qun-Wei Lin , Andrew Morton , Mike Rapoport , Matthias Brugger , AngeloGioacchino Del Regno , Sergey Senozhatsky , Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Casper Li , Chinwen Chang , Andrew Yang , James Hsu Subject: Re: [PATCH] mm: Add Kcompressd for accelerated memory compression Date: Wed, 07 May 2025 11:12:27 -0400 X-Mailer: MailMate (2.0r6255) Message-ID: <5D8BCC32-4932-4030-AE42-C0009D92A7CA@nvidia.com> In-Reply-To: References: <20250430082651.3152444-1-qun-wei.lin@mediatek.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: BL0PR0102CA0067.prod.exchangelabs.com (2603:10b6:208:25::44) To DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR12MB9473:EE_|SA0PR12MB4397:EE_ X-MS-Office365-Filtering-Correlation-Id: ae180b5d-d4ba-43b5-6eb7-08dd8d7995c7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?NG84KzJNY2wydzRsdm52YWNuNmxTN3lieWV3UUwzMU9xVzhEWnY5dnkwWFpB?= =?utf-8?B?aUNQQzF3SzVoSFNsWHVxYVdCNnlZdHN6ZHlJOW9lcUI5L1dIZ0ZDUnMxMzVN?= =?utf-8?B?MDd1bEEwU2wybHpSbGhDeG9peTVQWlhPUnk1NGsxYUxJY2xNcC9XMGpGdW5P?= =?utf-8?B?eWo5VjJLNzBveHZyMWxCYmZvVXpsbHFUVUR1Q085VHgvSkdlZjNhdzYvNklO?= =?utf-8?B?aUVndzd1MHRJQTdZRUg3S1ZIRHo2R3JvWkFmaVhQSEJaRUVySm8xdm1QSjJk?= =?utf-8?B?andVVk1mWFJEMktzbjJrVXpadnQrekUwd0s4RjNaSzYwNkxjV1hLL3JwMjZD?= =?utf-8?B?cm04ekEvc0NUZWwzenRyaktUMEpFdmJwekdtSmFvemNYTXhENFNVTEhzVDBp?= =?utf-8?B?ckJOKytaWHI5dHBxQkEzS2d6d3cyYnl5aVhDTWh0VXB5V2tjS2QzcWlXa252?= =?utf-8?B?U2l2S3Bnc3FyZ2gvZmF5Ykp4UDd5QWhVS25hbHl0K2Nmdm9ScFhFTlJoenky?= =?utf-8?B?TUVKNkI4RGhkUEdXeW1MbnYyNWhJY2kxQzFtazFEMXNZR00vSnEwV05zZ1h1?= =?utf-8?B?MnBVUXV1UVU4eVhIaUxNcXU0TlBRR2d4V2hBR1liaTh6VWpWNEtzb2thaGdz?= =?utf-8?B?Y2VwT2Zhd0oxVlpxeEJTbUkrekZBUURaQ1N2Z1FSYVJKenpyMzdyUDYydXlk?= =?utf-8?B?VldINHFlb3F0WGlzT0FCOG91M1oycDlQNFlSNFh6ZzZzVUxqbmc2R0RjeTVK?= =?utf-8?B?RFZTazJKU09mVS9qVWdVMjk0LzByZTNha1d2T1UxbG40Wk1oT1Y4REkvaE9H?= =?utf-8?B?R1VTcktLaXF5bnNIblBkaWs0cFYyOXBaSEFydkFldGg0a2JBcTVYcm90MURz?= =?utf-8?B?bkhNUTVpbC8yTjRPb0FjaTFJdzB6RTFJTGZKOHV3RkEwd1l3TXUyZ2xabm1K?= =?utf-8?B?RiswaXBDRmRTM2N0eGxWZjB5aC9ReDRMcFJ1eTdFSWQxaVAyaVlqYUdKVTVx?= =?utf-8?B?dE5teGZCNFVvUGkvRURtODgvL1pReG1obW1WUk9oOVBPbVIzajgzdE44SUtO?= =?utf-8?B?cXQxZUV3TmhydmZUUDRFNFN5Smo1RXBkamhYcDVocERZT0RLdTg1aDYzNmdM?= =?utf-8?B?YzRWRWFaU2dCaXlXUjdocTdPdDdRY1pEazgzU2xCanJJTkFCTlhDbnFCblN0?= =?utf-8?B?bHdVcXRkSUJmZkE1cmo1M0RWbllFUmZHZ3E5cmkwTGhxTk9rRmMxMkJiUG52?= =?utf-8?B?WW13K2VjZFBoS2c1MjU3TUY0azdWeVZYdUJvVDFPWDFoZFRyM2ljTlgxM2lS?= =?utf-8?B?N255dlVheWZTRXVFRmEvVThpUkJ1YzhzZXRnU2x5SzE3ejNjaVBxWm9MZmlh?= =?utf-8?B?U1RUUDhLSXFJK2RZRWJoVkQzOGVVMmJ3NW9QOHlsRExteVVlenpwN1dya0ts?= =?utf-8?B?aVJhaktybTVpTXBhMWhVRmwxZHVzY0FLbnVlck05KzFaWkhQakRIWSt2VXpB?= =?utf-8?B?eHJnS0Uzdisrb2V0eHdWeXE3c082c0lKbkVIL1hiQVNYRWRpdWlKTm9EN3JD?= =?utf-8?B?UHFrcmxlTDlpamtHY0tLNHBlUTdvb1Njc3ZMR0hrR1JUOWxPcDhQQ0xVaWc0?= =?utf-8?B?cFN0TXpUQXJ6YStFUkFxbUg2aCtoUTlzQUNVSklKbFc2VEhqU3g0eUEwQ1NW?= =?utf-8?B?YUZHRFN4UVQ4dFJ3eVFEaGErT3VLM3UzNURWZVgzUFM1aFNtV3psSG1ueFdo?= =?utf-8?B?RHZUbndvYW54cG9nZHZROHFQUk1YYklXa0diK3AwRDJMZlFuRVZqNnpSQVd4?= =?utf-8?B?MGV0VFZkRk41ckg5VDRlZlU0Qm5CRWZJbHRqaVBJT0Z4LzlhdWtSSncyd2Vv?= =?utf-8?B?dXEvWVVuTHM5KzhDWEtMeWN6TnlyOUVqNkpOalhmdTErRHo1MFpYWHVGYW9H?= =?utf-8?Q?m2oJSJ4AxDc=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR12MB9473.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(7416014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SDN0SXpwMXZLT09rQlFOMzdWQTVRNGlWTjRUUzJRenV6amRjK0szUnRucjNh?= =?utf-8?B?NGRxZUFSM2c3QVY0RjFsMytaaVBtdmh0RnNnZFVaK25ETjdKQXFLK1BBbnlv?= =?utf-8?B?dXhvRVNoVkpDOWNwVjVXcWUxSzd4SEdneS9DaVlrU1RwUk5nSnRPQmRBVkxq?= =?utf-8?B?R3Z3bjRTd3ptQVNleUVXdmh3QnRuSUtQWlMwUm9HY0kvOVNYZUxDdllFN05H?= =?utf-8?B?RnlQL0Vaak9heHZvUFhPTGJISWVIM091WXc1SmptYTUxb0pmSFdHRzNRMG5N?= =?utf-8?B?STVpc3VjeDl5RVJPcVpwblRvQnpRSlE0UjZ5MzdlRmhHdkYzU04walJ2bkJM?= =?utf-8?B?TzJZSGR1MTJneU9vd2dTOVlMSXdoL082T1dpRi9zb3o4YVZsL1BDUk8yanJF?= =?utf-8?B?WGFialNrWlNBd3NZYXBRQlhPVWRmaERFSnN6cklENWt6TlkwQUVNcVRzb243?= =?utf-8?B?WnlBRzlqVEpPRlV2alkwQTA4SWZ3QXVweGluVi9zamZKdDVnZHd2MmxYV0lk?= =?utf-8?B?UUlwSFhNTnlGQ3NLNHcyRmE1aFNOb1hrVHBEZkRlYlROZDNYRWI1Y2llenhn?= =?utf-8?B?b0xzSFhuMmxzZHlqd3lzb29qSWRVTUFzN3JjM2tJaUxDYS82b0Q2Vk41ZDFt?= =?utf-8?B?TTlyMk5vODY3bGUxKzBXQVhzRHV4VkxsNHVURlhJQktrVW9zVVAwcm5hNm9r?= =?utf-8?B?R2NxeVNPcXc5V2R1WmRGSU1obnlSbDVNZURqVk1ZZHQ4R3ptN1J5ZUUwbUJI?= =?utf-8?B?elQ0eXZPOTh4S25XRFNrbkk3R1FONVNFMUsxZEZEWUFpVm0wQ25ockhYb2Mv?= =?utf-8?B?dUhLNDVaaUtwMnB0R2huSjlMVnhrYWhOTnExM05hM2FWUnZGZEZvTm5kMjl6?= =?utf-8?B?QTVvbXJ6bTRzYktEbG1ycDBsWHJKUVhZTS9uTjN0eGJFdThjenVKZzhuMjh6?= =?utf-8?B?Y3hMWXd4OXBtUUtNQ2ZoNjgxQmFaTmNlOHBSOWJONHhiZHlzUkZQT1g5Ui9I?= =?utf-8?B?Rnl0SlFzS0VpMDRzajZVaDE1MXNsK3JHdkd0NHpiaGlyc1ZWRVNLdy90SnR4?= =?utf-8?B?b2gvK05aNXJCT0NyNWZteG1qemtvcnNmQWl4L0h5ZEdEL3B3UmVYWk9INE5C?= =?utf-8?B?aStzamhZMGIwWERsaGNFbmwybncyMEhqSTVXcHB3aWJaWDdjUVFHYVlEM0tk?= =?utf-8?B?aXJJWHJLN2FpbEcyVU9FaDUxQ1AxZWlqMlBUaWI0Y2lra1dNY1J1c09rRjY4?= =?utf-8?B?ZlIwRmVaWHE5c0dVTmtSR2IyRE5lMTFqN2RmYk80M1ErMC9aUGErSTgxOEhw?= =?utf-8?B?ZmU5SGlyYlR4ZFhGM3l0YU1Ddno5bVY4Y0EzSHkxZis1dzV0c3M1QTNyNnVo?= =?utf-8?B?anBHdTVrbEhKN2Z3UnNnZWl5UTl6U0ZYQXFXSWcrTU1DYkszenpEU0pxT2Rk?= =?utf-8?B?VU9Gb2U4Qzc2bWhib2JiMXRqUmlGcjVCWFFSQXV4LzIyZVovL0o4N0wvVStX?= =?utf-8?B?ZTRnZXZNeUxOQk9uZ2U4YTdXM2YwdllobmxRa2prKysxYW9hWXNJWVkzZWg3?= =?utf-8?B?RUI5bzhlU01HeVlPRm1wTWN5WFZCb1IvV3FBdFFpSEdSc3BPVVJ1ODJEZ0ZX?= =?utf-8?B?VEVlNmNWd0RxdXc5am1mM1hXUmUwZUVZeTJTUEduU1dLanJ2U3kvaEFjVEZ0?= =?utf-8?B?QXdTZ2hqSEpIbE9qWVV1bWc5bUZLbEFtK3FmZU41TDFlZ3ZHbldxRldQbkFq?= =?utf-8?B?TGpHcXVUU2h1d1drbGpKTXN6NHFXK3Nacmt3MUppOWwwNVAxcHBQTlFVS3lG?= =?utf-8?B?dlZsN2hBOHhYSHhvNGF1SjhneWh2WU9ZMGZxcTNRWnRLZERqdDcvWTBiTnJG?= =?utf-8?B?UTdYRkg1UGFwZHp1aGNKRVlNZlRacU4wcXRiTThXSlljOWlqNUxLQTcxRlJp?= =?utf-8?B?ODZUeC9LY0ppUzJ0dGpGRXdmZDlreUJzcFI0UjFqNEk1SVNvenViYzRsTXBT?= =?utf-8?B?alVtUmY1Vk9jaFduVjdwa2liMHZHR1piSVRyaXpQQlFTbXJOZ1l2OWcxRUt4?= =?utf-8?B?VGcwUGZHSzhtSnl3Y0JSdjRmbU53WU83aU1MWXlRdjdoUEUwRGVYcXlZZnA1?= =?utf-8?Q?8gzpZAChA0NXYKzPpkhEtDxK1?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ae180b5d-d4ba-43b5-6eb7-08dd8d7995c7 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 May 2025 15:12:30.1304 (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: hILnnq/QXUEY7LS007Z4+xKVMssPHqr0ovIOvzeGYmRwyJHK+UK/j/VhdS9d2Oc1 X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA0PR12MB4397 X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 2751840009 X-Stat-Signature: cknh7k6wojj1ttubwbcqf5789qz8os1z X-HE-Tag: 1746630762-351062 X-HE-Meta: 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 OaTqTGIT 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 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: List-Subscribe: List-Unsubscribe: On 7 May 2025, at 11:00, Nhat Pham wrote: > On Tue, May 6, 2025 at 7:04=E2=80=AFPM Barry Song <21cnbao@gmail.com> wro= te: >> >> On Wed, May 7, 2025 at 1:50=E2=80=AFPM Zi Yan wrote: >>> >>> On 6 May 2025, at 21:12, Harry Yoo wrote: >>> >>>> On Wed, Apr 30, 2025 at 04:26:41PM +0800, Qun-Wei Lin wrote: >>>>> This patch series introduces a new mechanism called kcompressd to >>>>> improve the efficiency of memory reclaiming in the operating system. >>>>> >>>>> Problem: >>>>> In the current system, the kswapd thread is responsible for both sc= anning >>>>> the LRU pages and handling memory compression tasks (such as those >>>>> involving ZSWAP/ZRAM, if enabled). This combined responsibility can= lead >>>>> to significant performance bottlenecks, especially under high memor= y >>>>> pressure. The kswapd thread becomes a single point of contention, c= ausing >>>>> delays in memory reclaiming and overall system performance degradat= ion. >>>>> >>>>> Solution: >>>>> Introduced kcompressd to handle asynchronous compression during mem= ory >>>>> reclaim, improving efficiency by offloading compression tasks from >>>>> kswapd. This allows kswapd to focus on its primary task of page rec= laim >>>>> without being burdened by the additional overhead of compression. >>>>> >>>>> In our handheld devices, we found that applying this mechanism under = high >>>>> memory pressure scenarios can increase the rate of pgsteal_anon per s= econd >>>>> by over 260% compared to the situation with only kswapd. Additionally= , we >>>>> observed a reduction of over 50% in page allocation stall occurrences= , >>>>> further demonstrating the effectiveness of kcompressd in alleviating = memory >>>>> pressure and improving system responsiveness. >>>>> >>>>> Co-developed-by: Barry Song <21cnbao@gmail.com> >>>>> Signed-off-by: Barry Song <21cnbao@gmail.com> >>>>> Signed-off-by: Qun-Wei Lin >>>>> Reference: Re: [PATCH 0/2] Improve Zram by separating compression con= text from kswapd - Barry Song >>>>> https://lore.kernel.org/lkml/20250313093005.13998-1-21cnbao@= gmail.com/ >>>>> --- >>>> >>>> +Cc Zi Yan, who might be interested in writing a framework (or improvi= ng >>>> the existing one, padata) for parallelizing jobs (e.g. migration/compr= ession) >>> >>> Thanks. >>> >>> I am currently looking into padata [1] to perform multithreaded page mi= gration > > TIL about padata :) > >>> copy job. But based on this patch, it seems that kcompressed is just an= additional >>> kernel thread of executing zswap_store(). Is there any need for perform= ing >>> compression with multiple threads? >> >> The current focus is on enabling kswapd to perform asynchronous compress= ion, >> which can significantly reduce direct reclaim and allocstall events. >> Therefore, the work begins with supporting a single thread. Supporting >> multiple threads might be possible in the future, but it could be diffic= ult >> to control=E2=80=94especially on busy phones=E2=80=94since it consumes m= ore power and may >> interfere with other threads impacting user experience. > > Right, yeah. > >> >>> >>> BTW, I also notice that zswap IAA compress batching patchset[2] is usin= g >>> hardware accelerator (Intel Analytics Accelerator) to speed up zswap. >>> I wonder if the handheld devices have similar hardware to get a similar= benefit. >> >> Usually, the answer is no. We use zRAM and CPU, but this patch aims to p= rovide >> a common capability that can be shared by both zRAM and zswap. >> > > Also, not everyone and every setup has access to hardware compression > accelerators :) This provides benefits for all users. Got it. Thanks for the explanation. -- Best Regards, Yan, Zi