From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from YT5PR01CU002.outbound.protection.outlook.com (mail-canadacentralazon11021084.outbound.protection.outlook.com [40.107.192.84]) (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 28FBA1F5820 for ; Mon, 15 Dec 2025 14:09:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.192.84 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765807746; cv=fail; b=DCKH8okqToojMPC9Glu7HoUsQgLVcPRsnflsKBVUWb9y3H9GjAcPc5N9nDf4LNxGkpq4L9AVWLuTN8IcK4mSq7RVwCKqzyKV7KZgFc8WdoX8Xpzpo8VM5CXlC4vAWtz0iZT7aFkCSD1ANSDwRs8KC1dXYd/pWS/h15YcK07RaqM= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765807746; c=relaxed/simple; bh=nbV/KCYvScn8mhmaRZQNBqKDX3FxQpO8nQQnU5w1oV0=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=KLVh569ERK7EJ0if9TF3iNu1lFWQLfVnbdqBGSIwqhkFIksuJiPR7XG3YWk5zDdW5VbHSLBY4mQ2WdnuxoH60ZRwTFGjQ+w6DuVWC4iaLOfC4Zr7T/uf/aU642Bt6dE+g3wbX/IokajadSzgm5ILwJr89tOx6Kw607Buqc07BPI= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=LaPNE5wj; arc=fail smtp.client-ip=40.107.192.84 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="LaPNE5wj" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=OKgsoMRO9eFbna5yP31QKVavwJK+09jcHgdzGePEN4soe20k6e+16IrvNh9/Wg+DBvzt1VB2w8vpgMnMdow38CSb/uD9GKG6mtduhF+my7qL6XiMgOgOK1Lg6YFP6QNQ8Levn1K884ULiceMD6DFVTeBXQSQHf/DXHPRbhxv1gGGKbbjyUG0C5HakSIXAysuY0ibrchY6Je3HiYmkid/7Uug//Hk9p2y57eeKeyd6qQ7KDI82QhMMYlk8SOy+jq4sxYEEnUy5K/228yoAkqwdy6FOZdpWGpSGjPCZ1zby6Q0inQB6MW4/1FjH8jiWvrqISnUoDLQfsyR1e9JDyvkdg== 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=vpWzCvDThl+uECLRVZhidvx1og6LbWfsMf6UHFAu7w8=; b=EUZk/Cu0dbvXSemAt7uHaj7KjOvYxjkc3+8JlJLw3mwsxeoUBwvEBifHV5yPW2oyGsY9UELyCkGjesgrBzdVrTQdYHCbu4yEYMUSqARiROMQHfEfL15tObsqtB01X+p/7SFNUkWwvXjBfSq/UvgWcQaxFleoWILhtPpFsu7Chec1cVcSRnEDkSiGbFB/0JoMhe7eGaNcony5Ip8mVNb9JJ5KfWfGRtDIRAhz5gtz80U7+6F9BOYjTUz59M2pvSqiNmsplaE1qx1l4U6Gmpd/kD2WYh+hePneHqMkBtMqfklqSSWX5hI0vSlHb5jF5a+5cqFOHY3zTlqQ3OgR0vW2Dg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=efficios.com; dmarc=pass action=none header.from=efficios.com; dkim=pass header.d=efficios.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=vpWzCvDThl+uECLRVZhidvx1og6LbWfsMf6UHFAu7w8=; b=LaPNE5wjzsPsCZkaJp0TFngyv05NEN0pD2x976ft1GcW0Sf5Pcsne4H9SZvWKMJatfwSlUdu0458clWt47vDiMT3ACa6K1pBQZP8PCB09X6UZlHRyFTdsw1w8vd12zZjCnOE6seyhppwHRlSIKXnNlM0jlJPOoBnPugj+WWvvaM7Y2PcZhdW6VRWkZYA7uY805OciuW35t4baFxidXyaXstv5MopwhqHYihneJ+qz0XxGD2Wz31NcEHnwt5b+qpGUyLndvBWazxuBvv7AsrPM3g7QAwmm6MO5l+e/o5tU0ZqIqN/ks82puqji3q2Ls3XaFNy0hwJTIJ/IWHWpId67Q== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=efficios.com; Received: from YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:be::5) by YQBPR0101MB5484.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:c01:47::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9412.13; Mon, 15 Dec 2025 14:08:57 +0000 Received: from YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM ([fe80::50f1:2e3f:a5dd:5b4]) by YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM ([fe80::50f1:2e3f:a5dd:5b4%2]) with mapi id 15.20.9412.011; Mon, 15 Dec 2025 14:08:56 +0000 Message-ID: <3d3f1675-7081-4744-bebd-2eb91c031d42@efficios.com> Date: Mon, 15 Dec 2025 09:08:55 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 0/3] mm: Fix OOM killer inaccuracy on large many-core systems To: Andrew Morton Cc: linux-kernel@vger.kernel.org, "Paul E. McKenney" , Steven Rostedt , Masami Hiramatsu , Dennis Zhou , Tejun Heo , Christoph Lameter , Martin Liu , David Rientjes , christian.koenig@amd.com, Shakeel Butt , SeongJae Park , Michal Hocko , Johannes Weiner , Sweet Tea Dorminy , Lorenzo Stoakes , "Liam R . Howlett" , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , Christian Brauner References: <20251213185608.3418096-1-mathieu.desnoyers@efficios.com> <20251214153550.10f171f0c98e4ece9a0f1bfe@linux-foundation.org> From: Mathieu Desnoyers Content-Language: en-US In-Reply-To: <20251214153550.10f171f0c98e4ece9a0f1bfe@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: YQBPR0101CA0344.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:c01:6b::28) To YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:be::5) 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: YT2PR01MB9175:EE_|YQBPR0101MB5484:EE_ X-MS-Office365-Filtering-Correlation-Id: 0b5f2e26-be81-4067-76dd-08de3be37ca7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?Ri9mckFLNkJPdHU5S1Q3Y2JPM2JVbDE3aEViQWhDQUQ5Q3ZWQTd4R2ROeE1X?= =?utf-8?B?ZXhzUXU4TkswS2I1K3luNjdqbkF5VFV5cFFXM3RKM2w0eUVvM1dYdGozdWhh?= =?utf-8?B?SHVMSE41TFNEQzBBdUc5dTNIL3lXQlZLL3ZJSnRuY2dYcVR4RW9ZTnJCWU0w?= =?utf-8?B?WDZHS3k3QjhRdmo5TWY5QW82VmRCQ292cG1IQjJheXc0OFZta1I4VFlZTCtk?= =?utf-8?B?cUdNM2NBRjIrdUVkTUM2RFdSajBSTE1KZnA1enA4T2hDUzNSNWp1RTY5VEk3?= =?utf-8?B?RTVvWVZON3RRaDNoQU9XTSsvQ3RjdERIclE4eU9TYW9Va2ordThRZks5MEZ4?= =?utf-8?B?aGxFRjdTcjZQV2o0Qll5OGJzWUlJNFY0azNWQlRoNlkxMkozRnM5VUNMWTJt?= =?utf-8?B?TlB3U3FNR3h1R2RKdkFscXJNR2dxMjV0N3pBOTNVYjlzeEEzUFBwb2xwVGdk?= =?utf-8?B?WVlJOUpZU2dwQVpjbmx1WDRvMzM2bHRvNFZWSlhwZmJzak9zVmgzRUlQWTA5?= =?utf-8?B?d25aVXpBbTJVSkFoM2NwSjVQUHUxa3hXK3huRVkwU1JQVHRHNjlVU2l6Vmx6?= =?utf-8?B?NXAvdk9FaWZhV2h0Q2lKRjUrd0JyM05RalNNZWxoT05WZGRvQi9kYmdNbjlw?= =?utf-8?B?MnllaitvaVlFVU56UE5JYnlCanZjQkFoWHNHY1hsM0NaZjBreVlJTFQ3WDdG?= =?utf-8?B?Q3JDRWNyRXNpR3BvRXFxWjlaL09JYnJRS2FJVmdRMzJ1QjR1UjFQeG5JeXZ6?= =?utf-8?B?em9jakgwRVY4MTR5Q0c4U3NEQlhib2NpOUYrRHUzQklSNjNUUFRRbm1IUUxN?= =?utf-8?B?RlhRSUFyNHBIazM2b3BhTldOV05JR3dRdDB6UWRINkc2S205TWR4bllvYmlK?= =?utf-8?B?djNGTCsySmRjU090ME5CL1Z2cWlpRjM3Q1UrNm1OWmREMk9MRlk5bWlOMXA4?= =?utf-8?B?RU5Sb2ZkSjNzWWU5K2RzUExYTm52RVlOTGZtcUp6N3NDSERRaVg1VHgyQVM5?= =?utf-8?B?TWx1aDE2eDlNNWhMM3Nzb1psREk3Z1l2aVpwYlRTSGJjYXIwcGl4ajJ6dW9K?= =?utf-8?B?VWpaR3UwdU8vZFc5eGYvMmJpQitoU1RDd2k1ZndQazlSTXF1WEJrVWJ5ZHc3?= =?utf-8?B?dzZvTXF5MkI1VnBETVY5WGgxUHk4NG45NGhCQ0R3elFCNzZhYWpjd28vRW02?= =?utf-8?B?UytObG1DNDNWb2ZXOXV1ZHh6SUI0TG1YUXFZdnVsZjR3SzE2am0rNm9zNmZW?= =?utf-8?B?TU1oZTkwU3RPYW9IcDZsdGh3OW5HNEhRUDEyYjhDbHZaT3dyNTBhcHJoR1N0?= =?utf-8?B?eG84ZjhRenZlOTVLVzVQb0RIejhzQkh5Vkw4TVlEY3hnOEFadjlJdmYzUVhu?= =?utf-8?B?Mk1qTFBDVWd1SjdCcE5DeEQyWEtKVXNqaEhPSXhuZHQxeVM3cVIxUUlZMzZl?= =?utf-8?B?Y2UyQ3ZpWUd0RFBVMk5FSkNqZWdIdzVZMGhRYWhsak5PMTFPejVrb1d6V3c0?= =?utf-8?B?UXhabnZMRlhtc2pKWTBuaWJzQ3JBOUgxUG5US2MyMkpCUlVNdUIzTHVXYVpO?= =?utf-8?B?Z3FaYWIxR3Fkc3U4a1FRb3dSZTV6M1FqdC9TMlJucFZQNzl6Nm9uQXFiWmZ2?= =?utf-8?B?ZTBkWVlyVmFkTUR1TTd3RmlGWUZ5RGE5WWkxUVlhK0xJeGVCZk1IT0JBaHA2?= =?utf-8?B?aEkyY1I2RWcwZGRwcGFIc3JjTkMwQUxyOTN1M2t0QnMzSVBBZ2ViRW9LSElX?= =?utf-8?B?aUxQVGd0c0cyTlpLQ2ZSdWlwdUl2VHRZWmNDVU9SdGZqaVNFUG04Si9tT2tv?= =?utf-8?B?d3NpQ2hxeFVyejZCM2tVZEJtS3F3aVRIRVRHZFlMQXB3UStVbFZ4Wlo4d3k3?= =?utf-8?B?cnBFRklKNVE5NFBBcHZDMkNRSGl4R1BVMUtsZnQvNTZ3dmc9PQ==?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230040)(366016)(7416014)(376014)(1800799024);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?b2tJTHlQTXJ5WHVrcml5YUVoWXpSU3IyYytpSEdRN0xZSjNpR20xdHFISjFN?= =?utf-8?B?NXovcCt4aWdSb1hYazBqWW1RTFRvam1tYkRjOW5saXRLZlVUTXNPc0NNTlox?= =?utf-8?B?Y2NoVkhuSVJVVWxpNEhCRXlZV2I2SDBma1ZVaDJ4bGYzYU5DbUNFSFBjNFhB?= =?utf-8?B?cUprZHVleU1uQ21RZlI2S1dyM0JtYTFYTG1TRFFXcDV0c2VlR3cwbmxzSWFL?= =?utf-8?B?dE1EWGdJeU9hc2FxaVVuTlRVbHd4YkkrUDhEbmlqUEFmN2FEd3V1MEo2cXN2?= =?utf-8?B?VmJUOVU5c25KMERScU1EOWFkdlVWTG5GRUNlWkxEaDF6YmdrYnRYSm4xMW50?= =?utf-8?B?QVJqYW5YVUlLVitZY2dRL1RxaGdqWjRkanoxN0J0aDd0M3Qxd1drbjUrNGMy?= =?utf-8?B?Vi9SZVBCU1M5aDNHK1NKT2VaZEhRdlVmdFk4S1VMMEtKb0VNa20zdTlUMi9t?= =?utf-8?B?UW5iV0tYTUJqMTZmOEJTQ2h1WStzNkJOZS9yU1lJK1BXdzY1QzY3YkxYTDhH?= =?utf-8?B?Qk95MUlQRXNFdUpaYnUzbHMycUxodUlzYVFkaTRGdGs3UHNrSERrTDNLb2t4?= =?utf-8?B?SjYzVnN1UldVampmdmFzVE5jWm9pcEJheU41QnJjS1hNc2lUNkZZb0UvTlE1?= =?utf-8?B?bVlnVG5SbzBZTnUxdkZMRlNkZlg3VG5vcFA2U0lyUTNBR1Arbmk2SjNCR3dr?= =?utf-8?B?K2JRbFBQRXphcU1GbmFOV3Ric3Vqb1JzaElzQlFUN0UyS2F2dDgzTVpNYlRl?= =?utf-8?B?NExzN1lWeGkzMHdqazluVnVMeGdVOVdCZHJkcVFDZnkxNjFuMGJrbXAwRVFT?= =?utf-8?B?TUw5b1Q5Z1c2ZWZTWVU0NkpxWlRIYlhCK3RkU0JnYkJxbkJZWkRadjRDbThv?= =?utf-8?B?aXZWRURFdGhJWDVIRTBzUWg5bVJYUkJmOWVIRzJYeGRHRC94V240QnZIbGQ4?= =?utf-8?B?SVRpNlhPVVhZNWJZK1E4T08xN3N0TUZjT3FaRWt5N3g2WDhzb1N4OVBhdkpy?= =?utf-8?B?VTg1SWp1MThxQjcrMmFHRW9ocUgwUHpQb1N2dGVzU01oTndXZVMwV1UySXlK?= =?utf-8?B?M2R4Q1JZNGVzdzBVSXRJT3NENjlUdEw3by9LNk9ndzBVb280N1I3VUZhNk9X?= =?utf-8?B?cUdiZXZ4azA3dCtNVmFxNkFyd2hGSG43ZWpIY1lEZjg5VlVRQW44U3VlcGpU?= =?utf-8?B?U2p6eDBCamlmRXEwS010dFFyWGI2ZGtuSXhVTWMxOHRNZU9KK2VzNUdjQksz?= =?utf-8?B?NUxaZ2dYRzZrMk1TS0ovc0p0eWdGNEs5K1k1RlgvM05SY2FRK216Y0Vja05w?= =?utf-8?B?bDZSMVE1RUZLcnNFeVp0dDlPbmQ0eXZYTHpDY3hhc0tySVdzOG0zZjVqUDRt?= =?utf-8?B?ZHRDaVJuMG50YllTd3I1UHlLNWFjcFBBL0V0V2lYQ1dRQjdGK3FhakVld0Nu?= =?utf-8?B?bTRxRGg0NnNER3UxWFB5aEZFb2pxdThnS3FGQUYzZVI0cFFram1JY2UxN084?= =?utf-8?B?VjloVytpSXJIZExRMlVhMFBiQnVFWnZsNVBsWnNiaUdpNWdXZFBOYnRROEMx?= =?utf-8?B?b0hKWWYySktDeWIvZk9kZXdIV2lKbERFUHpPcE4xMzVoclkwU0o4eURNcTlJ?= =?utf-8?B?OEtqTmJ6WWd1KytXbXU4akkvTnNHSmtwS2xjMytTdE45a2ZmRGZ3Qi9XSzJr?= =?utf-8?B?Y2ZlcldFVEtkVHdsQ2REcFpUbGY3YWVkdU00bmsvZVJNd2ZQSzFaek5CSFdJ?= =?utf-8?B?eER1YTFWOVd0VnYzR2JyazJxRGFaUHU3YnZLNHRNeGNjUEh3UUx0Um00R2FT?= =?utf-8?B?elZVYTNmaUU3Qit5QzI0MlMxSWIrNWU1NFYzNWM5MTlLUzM3aitIL21vY0h1?= =?utf-8?B?dzZydkxmNVFteFhFY2pja2wvTXBNbjI4V2pmRWxjakFZWDF6Ykk2ZmcycHpP?= =?utf-8?B?djhyM2lFQkJJZGtPM1VkMGVkdmhKMDJOMVZqSDg5SjdyVHNlUWd0UWtIeWdG?= =?utf-8?B?M002MTlRdW5xazBld1FIY2tvRTlGcXZCM08zWGJwa3BPdHpQdkdnQldUeHFu?= =?utf-8?B?Snh6U1k2Mk11ZlNGMWdhU3R3RHZjQ2JSbjAveS9xV2ZTdnl0dy9HeWIrQnBW?= =?utf-8?B?aU1zeG0yNjkvZlYwZlJWd0VVOGZYS09tK3BxbmJXaHdrZUpiN1YveCtXczRk?= =?utf-8?Q?pGpDYqro/bcHD45WFWl0eO0=3D?= X-OriginatorOrg: efficios.com X-MS-Exchange-CrossTenant-Network-Message-Id: 0b5f2e26-be81-4067-76dd-08de3be37ca7 X-MS-Exchange-CrossTenant-AuthSource: YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Dec 2025 14:08:56.9225 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4f278736-4ab6-415c-957e-1f55336bd31e X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: ctn0JNhvtbmx6g1cmT+Rx7od2zexfmNdV3Ir0o9iuanzkDCeWxmgfxGkgA/LJMafsQjpGS49zAAq00TWP328UtNdQpOuwvM7vWR3+M2yFys= X-MS-Exchange-Transport-CrossTenantHeadersStamped: YQBPR0101MB5484 On 2025-12-14 18:35, Andrew Morton wrote: > On Sat, 13 Dec 2025 13:56:05 -0500 Mathieu Desnoyers wrote: [...] >> >> Andrew, are you interested to try this out in mm-new ? > > Yes. We have to start somewhere. Cool ! > > As you kind of mention, it's going to be difficult to determine when > this is ready to go upstream. I assume that to really know this will > required detailed and lengthy fleet-wide operation and observation. For that kind of feature, yes, this is my expectation as well. > What sort of drawbacks do you think people miht encounter with this > change? Let's see, here are some possible drawbacks to keep an eye out for: - Taking for instance a machine with 256 logical CPUs topology, although allocation for small amount of memory is typically handled with a this_cpu_add_return, when doing large memory allocations, this will trickle up the carry over 3 levels, each of which require an atomic_add_return. The upstream implementation would instead go straight for a global spinlock, which may or may not be better than 3 atomics. - 2-pass OOM killer task selection: with a large number of tasks, and small number of CPUs, the upstream algorithm would be adequately precise, and faster because it does a single iteration pass. So the open question here is do we care about overhead of the OOM killer task selection ? - I understanding that some people implement their own OOM killer in userspace based on RSS values exposed through /proc. Because those RSS values are the precise counts (split-counter sums), there should be no difference there compared to the upstream implementation, but there would be no performance gain as well. It may be interesting to eventually expose the counter approximations (and the accuracy intervals) to userspace so it could speed up its task selection eventually. Not really a drawback, more something to keep in mind as future improvement. - I took care not to add additional memory allocation to the mm allocation/free code because it regresses some benchmarks. Still it's good to keep an eye out for bot reports about those regressions. - The intermediate tree levels counters use extra memory. This is a tradeoff between compactness and cache locality of the counters. I currently used cache-aligned integers (thus favored cache locality and eliminating false-sharing), but I have other prototypes which use packed bytes for the intermediate levels. For instance, on a 256 core machine, we have 37 intermediate levels nodes, for a total of 2368 bytes (that's in addition to the 1024 bytes of per-cpu memory for the per-cpu counters). If we choose to instead go for the packed bytes approach, the 37 intermediate levels nodes will use 37 bytes of memory, but there will be false-sharing across those counters. An alternative approach there is to use a strided allocator [1] with a byte counter set allocator on top [2]. This way we can benefit from the memory savings of byte counters without the false-sharing. Thanks, Mathieu [1] https://github.com/compudj/librseq/blob/percpu-counter-byte/src/rseq-mempool.c [2] https://github.com/compudj/librseq/blob/percpu-counter-byte/src/percpu-counter-tree.c#L190 -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com