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 6997AC4332F for ; Fri, 3 Nov 2023 14:16:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DDCCC28001C; Fri, 3 Nov 2023 10:16:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D8D5528000F; Fri, 3 Nov 2023 10:16:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C548128001C; Fri, 3 Nov 2023 10:16:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id B66DA28000F for ; Fri, 3 Nov 2023 10:16:49 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 670EC1CB8AF for ; Fri, 3 Nov 2023 14:16:49 +0000 (UTC) X-FDA: 81416844138.17.B849C33 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by imf05.hostedemail.com (Postfix) with ESMTP id 010FA100013 for ; Fri, 3 Nov 2023 14:16:45 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of jonathan.cameron@huawei.com designates 185.176.79.56 as permitted sender) smtp.mailfrom=jonathan.cameron@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1699021007; a=rsa-sha256; cv=none; b=pr67e9Tvi0yT43KB5VX3YEfNfacfH4Z+M5owvDvYS1cte/9tBrRSmNM20+4hGjLQQdaEi0 FTn6nDVbQAtJXLZmGAPRxYBqZz/1x6YmkEEjH3CjM6pbff/IHa5koQe2Ddzy3k/cXZLL36 CNBeFNoiztOLX3/kQzR3J+qghzMvxOs= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of jonathan.cameron@huawei.com designates 185.176.79.56 as permitted sender) smtp.mailfrom=jonathan.cameron@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1699021007; 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; bh=zelsxvkOnqldazVBhc1xi08VKZtQaLMjFaA7I3L0gQs=; b=8Uhp/BlnjvDuV8rF+b7cTQkz3IIPMAlDThZzk+E/DFsRAxMM/QEVigeYdcOVy3Yh99TlPm MyAClfgxlzBPnhNrvLWkU0FdKMkTydSj56OX972R4D4Gxo3PLxRsVNZjmsWDFf5fcTlsxz vsnImeRUFeWRXdvhm6uPD7cIJt6rvqc= Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4SMN505bbhz689SY; Fri, 3 Nov 2023 22:13:24 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Fri, 3 Nov 2023 14:16:37 +0000 Date: Fri, 3 Nov 2023 14:16:36 +0000 From: Jonathan Cameron To: "Huang, Ying" , Gregory Price CC: Michal Hocko , Johannes Weiner , Gregory Price , , , , , , , , , , , , Subject: Re: [RFC PATCH v3 0/4] Node Weights and Weighted Interleave Message-ID: <20231103141636.000007e4@Huawei.com> In-Reply-To: <87fs1nz3ee.fsf@yhuang6-desk2.ccr.corp.intel.com> References: <20231031003810.4532-1-gregory.price@memverge.com> <20231031152142.GA3029315@cmpxchg.org> <87fs1nz3ee.fsf@yhuang6-desk2.ccr.corp.intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml500004.china.huawei.com (7.191.163.9) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 010FA100013 X-Stat-Signature: jgzrky8uupgt4gjfqkeq59mu5c6bds3q X-HE-Tag: 1699021005-111720 X-HE-Meta: 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 k2jluaco F53tEfAWUmTW3zzs12lWjYANN9ZivwqJ14zd1AtDJtPNxeFPIJFJbm818jMg3YrFRcAb/8YABv+96B/vomSGQZkNtKm2wR5wagbXwEFRm5Avjt5DuxNWq4D7sieUsJk81CNold3vD6m+NovX1L2ycl/f8F38BFd4TaXoHXh+H7VZeL4wjuKwckmZhtsdBGQOyMQzNJQnXZ0CtpOse/SvqEg5k8gwxpc6F3/70hHsccXLn/GjFc1yZHhSk/wsFH4tG45yyJanNUa8mAe1HZlGc8eA4yFZA86TA84wMHBIme/IWrGpisn4gtPZM8767sWO5mejn9lZnmZiBAGogZvt3GaguHm+f78LqlY4tyAgIvpksHfE= 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 Fri, 03 Nov 2023 15:45:13 +0800 "Huang, Ying" wrote: > Gregory Price writes: > > > On Thu, Nov 02, 2023 at 10:47:33AM +0100, Michal Hocko wrote: > >> On Wed 01-11-23 12:58:55, Gregory Price wrote: > >> > Basically consider: `numactl --interleave=all ...` > >> > > >> > If `--weights=...`: when a node hotplug event occurs, there is no > >> > recourse for adding a weight for the new node (it will default to 1). > >> > >> Correct and this is what I was asking about in an earlier email. How > >> much do we really need to consider this setup. Is this something nice to > >> have or does the nature of the technology requires to be fully dynamic > >> and expect new nodes coming up at any moment? > >> > > > > Dynamic Capacity is expected to cause a numa node to change size (in > > number of memory blocks) rather than cause numa nodes to come and go, so > > maybe handling the full node hotplug is a bit of an overreach. > > Will node max bandwidth change with the number of memory blocks? Typically no as even a single memory extent would probably be interleaved across all the actual memory devices (think DIMMS for simplicity) within a CXL device. I guess a device 'could' do some scaling based on capacity provided to a particular host but feels like they should be separate controls. I don't recall there being anything in the specification to suggest the need to recheck the CDAT info for updates when DC add / remove events happen. Mind you, who knows in future :) We'll point out in relevant forums that doing so would be very hard to handle cleanly in Linux. Jonathan