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[23.128.96.18]) by mx.google.com with ESMTP id s9si15594362pfu.100.2022.02.09.04.22.28; Wed, 09 Feb 2022 04:22:42 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=desiato.20200630 header.b=LZ3304J7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231328AbiBILzT (ORCPT + 99 others); Wed, 9 Feb 2022 06:55:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231203AbiBILzL (ORCPT ); Wed, 9 Feb 2022 06:55:11 -0500 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 79167C05CBA9 for ; Wed, 9 Feb 2022 02:46:51 -0800 (PST) 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=GkFncH3D98WWU5j3nygIVV9IJgCRQDVabHsVvuLcQhI=; b=LZ3304J7qWfUhOQlgypmXiZFvV aB0eujBTl0pmXDqJeC3qOxUcZX1ceBDfZ4yuTS11NaiY+RxMAuRHEtaxcpB6DYwr44vXuDfE/4aMF jsAWsUNa3Zh9NstE0JlF71q1QEK+VUmFFYMZ0EUMDk3DjdLuzvMa5zfGZspbMn19LBGw3U2ptwSX4 34XBtqYGi2AwEtiV+rVaaoPNkEAHtIQclSmnn6eKmShM4siOBTALEyiNpL8rVlYQlwgYjfCA4XKzm rc1ZJwyV7UMGOe7qDgm3iBjqr9Y/GWsznQNQsvXo2FwezdLweWGw99/tSt+djHd05YxK5bi7J3a6d XABezw/g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHkUV-008Os7-Hf; Wed, 09 Feb 2022 10:46:28 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id B098A9853C7; Wed, 9 Feb 2022 11:46:25 +0100 (CET) Date: Wed, 9 Feb 2022 11:46:25 +0100 From: Peter Zijlstra To: K Prateek Nayak Cc: aubrey.li@linux.intel.com, efault@gmx.de, gautham.shenoy@amd.com, linux-kernel@vger.kernel.org, mgorman@techsingularity.net, mingo@kernel.org, song.bao.hua@hisilicon.com, srikar@linux.vnet.ibm.com, valentin.schneider@arm.com, vincent.guittot@linaro.org Subject: Re: [PATCH] sched/fair: Consider cpu affinity when allowing NUMA imbalance in find_idlest_group Message-ID: <20220209104625.GM23216@worktop.programming.kicks-ass.net> References: <20220207155921.21321-1-kprateek.nayak@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220207155921.21321-1-kprateek.nayak@amd.com> X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 07, 2022 at 09:29:21PM +0530, K Prateek Nayak wrote: > Neither the sched/tip nor Mel's v5 patchset [1] provides an optimal > new-task wakeup strategy when the tasks are affined to a subset of cpus > which can result in piling of tasks on the same set of CPU in a NUMA > group despite there being other cpus in a different NUMA group where the > task could have run in. Where does this affinity come from?