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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6815C7619A for ; Wed, 12 Apr 2023 12:08:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230061AbjDLMIT (ORCPT ); Wed, 12 Apr 2023 08:08:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229751AbjDLMIS (ORCPT ); Wed, 12 Apr 2023 08:08:18 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AC6E4EDA for ; Wed, 12 Apr 2023 05:08:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=X6WFaagDxA1HSNNorPLlMI2u9P5Ku6tSIBRxh0ocD30=; b=ABhlM9wUckgXQJWL6kJDkzboco RGXw5Hg+GfMYXPpSrUSOCsLO5j7giKKNBUio/BjF3jHHWlDj8ny7A0Qf8iCdKL1n6iEm8uR3JS1Qx xNUyTmJgYSt2D3LFDpSOw+qK15vjUBYh1ICjy54ycwE10yrOp1Q9YRF+rDZyy6JTu0xJUldMTmJ+b XEr9uRFzyaCtb7wlukH+l2MK9juccfw/zwDMciwgrUEsNEc7D9c6qU5eMF4S3q4hE5q4dNl2pHfSs Pzz+w/acszRDsYTMAbdJLSQoIw9Amjmc65ePuB0vc+1eBgCsFaxp/tS71ZmnzV3V7JAVyTanHRevu yXv9Yk/Q==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1pmZGE-00DuvH-1U; Wed, 12 Apr 2023 12:07:38 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id A57523002A6; Wed, 12 Apr 2023 14:07:36 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 88F3D235CC4CB; Wed, 12 Apr 2023 14:07:36 +0200 (CEST) Date: Wed, 12 Apr 2023 14:07:36 +0200 From: Peter Zijlstra To: Daniel Jordan Cc: Aaron Lu , Dietmar Eggemann , Ingo Molnar , Juri Lelli , Vincent Guittot , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , Tim Chen , Nitin Tekchandani , Waiman Long , Yu Chen , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] sched/fair: Make tg->load_avg per node Message-ID: <20230412120736.GD628377@hirez.programming.kicks-ass.net> References: <20230327053955.GA570404@ziqianlu-desk2> <943d44f7-1fa9-8545-dc1d-890e4dd20854@arm.com> <20230328125624.GA6130@ziqianlu-desk2> <76939bf6-1d9d-5f8f-f15c-f03b2322d684@arm.com> <20230329135455.GA108864@ziqianlu-desk2> <20230330174557.m6jsgb6hsni4mxwq@parnassus.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230330174557.m6jsgb6hsni4mxwq@parnassus.localdomain> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 30, 2023 at 01:45:57PM -0400, Daniel Jordan wrote: > The topology of my machine is different from yours, but it's the biggest > I have, and I'm assuming cpu count is more important than topology when > reproducing the remote accesses. I also tried on Core count definitely matters some, but the thing that really hurts is the cross-node (and cross-cache, which for intel happens to be the same set) atomics. I suppose the thing to measure is where this cost rises most sharply on the AMD platforms -- is that cross LLC or cross Node? I mean, setting up the split at boot time is fairly straight forward and we could equally well split at LLC.