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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65E39C28CC2 for ; Fri, 31 May 2019 09:38:02 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3EA6F266FF for ; Fri, 31 May 2019 09:38:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QM2gDbr/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3EA6F266FF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=VvYOfpGbR206HAKG+sqEodN4lAsS9BX4GD7PQRpT9aQ=; b=QM2gDbr/dwyR7e o7ZJ7e5Eccacl7IXGapHKuTZfClDG7xGnfsx4vbMU8k/dypo1KECtWR+MFfiR6ECK4qc8Gw6Q9FsI WDgzjKa8SwwHFgyfOKYDjB7N8qL45An16Tc+Vd9XZqu+Wb8nF2f5sr+/d5V4Fb16ZS0CciVqhqaNO n5WmuCl01OZdH0q3g03yJRXSRlsLxuX913Kthn9EAdwD6daJSrJ47FqUoa2K1/mmEvykMG3t78+mb OM8Zbs2Qe3ef9bgulskbfoBrm5DL7mA8mIcdNbOnlNtHWYqx7aH2ubyunRudOS7wu3Sa+kPFZQBhv fEr1q8dGIhmvj5EAz20g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hWdz5-0003m2-6f; Fri, 31 May 2019 09:37:59 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hWdyx-0003eX-5P; Fri, 31 May 2019 09:37:52 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 735ED341; Fri, 31 May 2019 02:37:50 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 106B93F59C; Fri, 31 May 2019 02:37:45 -0700 (PDT) Date: Fri, 31 May 2019 10:37:43 +0100 From: Sudeep Holla To: Russell King - ARM Linux admin Subject: Re: [PATCH v6 1/7] Documentation: DT: arm: add support for sockets defining package boundaries Message-ID: <20190531093743.GB18292@e107155-lin> References: <20190529211340.17087-1-atish.patra@wdc.com> <20190529211340.17087-2-atish.patra@wdc.com> <49f41e62-5354-a674-d95f-5f63851a0ca6@ti.com> <20190530115103.GA10919@e105550-lin.cambridge.arm.com> <20190530214254.tuxsnyv52a2fyhck@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190530214254.tuxsnyv52a2fyhck@shell.armlinux.org.uk> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190531_023751_217712_DB891A12 X-CRM114-Status: GOOD ( 22.78 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , "Rafael J. Wysocki" , "Peter Zijlstra \(Intel\)" , Catalin Marinas , Linus Walleij , Palmer Dabbelt , Will Deacon , Atish Patra , Mauro Carvalho Chehab , linux-riscv@lists.infradead.org, Ingo Molnar , Rob Herring , Anup Patel , Morten Rasmussen , devicetree@vger.kernel.org, Albert Ou , Rob Herring , Paul Walmsley , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Jeremy Linton , "Andrew F. Davis" , Otto Sabart , Sudeep Holla , "David S. Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, May 30, 2019 at 10:42:54PM +0100, Russell King - ARM Linux admin wrote: > On Thu, May 30, 2019 at 12:51:03PM +0100, Morten Rasmussen wrote: > > On Wed, May 29, 2019 at 07:39:17PM -0400, Andrew F. Davis wrote: > > > On 5/29/19 5:13 PM, Atish Patra wrote: > > > >From: Sudeep Holla > > > > > > > >The current ARM DT topology description provides the operating system > > > >with a topological view of the system that is based on leaf nodes > > > >representing either cores or threads (in an SMT system) and a > > > >hierarchical set of cluster nodes that creates a hierarchical topology > > > >view of how those cores and threads are grouped. > > > > > > > >However this hierarchical representation of clusters does not allow to > > > >describe what topology level actually represents the physical package or > > > >the socket boundary, which is a key piece of information to be used by > > > >an operating system to optimize resource allocation and scheduling. > > > > > > > > > > Are physical package descriptions really needed? What does "socket" imply > > > that a higher layer "cluster" node grouping does not? It doesn't imply a > > > different NUMA distance and the definition of "socket" is already not well > > > defined, is a dual chiplet processor not just a fancy dual "socket" or are > > > dual "sockets" on a server board "slotket" card, will we need new names for > > > those too.. > > > > Socket (or package) just implies what you suggest, a grouping of CPUs > > based on the physical socket (or package). Some resources might be > > associated with packages and more importantly socket information is > > exposed to user-space. At the moment clusters are being exposed to > > user-space as sockets which is less than ideal for some topologies. > > Please point out a 32-bit ARM system that has multiple "socket"s. > > As far as I'm aware, all 32-bit systems do not have socketed CPUs > (modern ARM CPUs are part of a larger SoC), and the CPUs are always > in one package. > > Even the test systems I've seen do not have socketed CPUs. > As far as we know, there's none. So we simply have to assume all those systems are single socket(IOW all CPUs reside inside a single SoC package) system. -- Regards, Sudeep _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv