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 B7D30C433F5 for ; Thu, 25 Nov 2021 15:21:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355865AbhKYPZG (ORCPT ); Thu, 25 Nov 2021 10:25:06 -0500 Received: from outbound-smtp32.blacknight.com ([81.17.249.64]:35958 "EHLO outbound-smtp32.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355841AbhKYPXF (ORCPT ); Thu, 25 Nov 2021 10:23:05 -0500 Received: from mail.blacknight.com (pemlinmail04.blacknight.ie [81.17.254.17]) by outbound-smtp32.blacknight.com (Postfix) with ESMTPS id EDAB9BF085 for ; Thu, 25 Nov 2021 15:19:52 +0000 (GMT) Received: (qmail 25424 invoked from network); 25 Nov 2021 15:19:52 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.17.29]) by 81.17.254.9 with ESMTPA; 25 Nov 2021 15:19:52 -0000 From: Mel Gorman To: Peter Zijlstra Cc: Ingo Molnar , Vincent Guittot , Valentin Schneider , Aubrey Li , Barry Song , Mike Galbraith , Srikar Dronamraju , LKML , Mel Gorman Subject: [PATCH 0/2] Adjust NUMA imbalance for multiple LLCs Date: Thu, 25 Nov 2021 15:19:39 +0000 Message-Id: <20211125151941.8710-1-mgorman@techsingularity.net> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 7d2b5dd0bcc4 ("sched/numa: Allow a floating imbalance between NUMA nodes") allowed an imbalance between NUMA nodes such that communicating tasks would not be pulled apart by the load balancer. This works fine when there is a 1:1 relationship between LLC and node but can be suboptimal for multiple LLCs if independent tasks prematurely use CPUs sharing cache. The series addresses two problems -- inconsistent use of scheduler domain weights and sub-optimal performance when there are many LLCs per NUMA node. include/linux/sched/topology.h | 1 + kernel/sched/fair.c | 26 +++++++++++++++----------- kernel/sched/topology.c | 24 ++++++++++++++++++++++++ 3 files changed, 40 insertions(+), 11 deletions(-) -- 2.31.1