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 F087CC433EF for ; Wed, 18 May 2022 13:59:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238358AbiERN7v (ORCPT ); Wed, 18 May 2022 09:59:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229721AbiERN7t (ORCPT ); Wed, 18 May 2022 09:59:49 -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 6CBC41A7D28 for ; Wed, 18 May 2022 06:59:47 -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=diFgENTszdQUHXAKgwYmdyZMPkaYBZcehcdCuI+8CNI=; b=piMPTHj0XG5LeId6adfAZJaoiu gsW2AlDfqunjvacbNZ/xs4ODNR4GizI/LByJtwiD30R11aQIkyOmX3NDkQ+jgnqWMOXc2GtT0LE99 PnDJ0pGknFeTbCpw1F3+NIjAuuv9Irh5ovdQgb6UNJZjvzQORVnts4X88IrdFjxtgT/dN4UjZy2U4 Pwcu9m61SgyVlI3lZ4ECgfKR4hlHsnRgSJ0GLCv5J3YLYLJVpHfol+t5/bnuuLbonzVNv0nvliGUw p1Nn5EKLXc/vLbBXxIaO9APm0HBwzecwb7RCKeNfiyPB/BGf08Iog1J9oDAQouGohRcGq2u2vAdDR urBkCclg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nrKD9-001YVZ-N4; Wed, 18 May 2022 13:59:36 +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 1AFB93003AA; Wed, 18 May 2022 15:59:35 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 00C42202391E4; Wed, 18 May 2022 15:59:34 +0200 (CEST) Date: Wed, 18 May 2022 15:59:34 +0200 From: Peter Zijlstra To: Mel Gorman Cc: Ingo Molnar , Vincent Guittot , Valentin Schneider , Aubrey Li , LKML Subject: Re: [PATCH 3/4] sched/numa: Apply imbalance limitations consistently Message-ID: References: <20220511143038.4620-1-mgorman@techsingularity.net> <20220511143038.4620-4-mgorman@techsingularity.net> <20220518093156.GD10117@worktop.programming.kicks-ass.net> <20220518104652.GO3441@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220518104652.GO3441@techsingularity.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 18, 2022 at 11:46:52AM +0100, Mel Gorman wrote: > > (Although I do wonder about that 25% figure in the comment; that doesn't > > seem to relate to any actual code anymore) > > > > You're right, by the end of the series it's completely inaccurate and > currently it's not accurate if there are multiple LLCs per node. I > adjusted the wording to "Allow a NUMA imbalance if busy CPUs is less > than the maximum threshold. Above this threshold, individual tasks may > be contending for both memory bandwidth and any shared HT resources." > Looks good. Meanwhile I saw a 0-day complaint that this regresses something something unixbench by a bit. Do we care enough? I suppose this is one of those trade-off patches again, win some, loose some.