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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 D1E76C7618B for ; Tue, 23 Jul 2019 13:03:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B93D218BE for ; Tue, 23 Jul 2019 13:03:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390050AbfGWND0 (ORCPT ); Tue, 23 Jul 2019 09:03:26 -0400 Received: from outbound-smtp29.blacknight.com ([81.17.249.32]:54464 "EHLO outbound-smtp29.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731916AbfGWND0 (ORCPT ); Tue, 23 Jul 2019 09:03:26 -0400 Received: from mail.blacknight.com (unknown [81.17.254.26]) by outbound-smtp29.blacknight.com (Postfix) with ESMTPS id E59A1D0239 for ; Tue, 23 Jul 2019 14:03:23 +0100 (IST) Received: (qmail 32687 invoked from network); 23 Jul 2019 13:03:23 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.21.36]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 23 Jul 2019 13:03:23 -0000 Date: Tue, 23 Jul 2019 14:03:21 +0100 From: Mel Gorman To: Peter Zijlstra Cc: Matt Fleming , linux-kernel@vger.kernel.org, "Suthikulpanit, Suravee" , "Lendacky, Thomas" , Borislav Petkov Subject: Re: [PATCH v3] sched/topology: Improve load balancing on AMD EPYC Message-ID: <20190723130321.GK24383@techsingularity.net> References: <20190723104830.26623-1-matt@codeblueprint.co.uk> <20190723114248.GJ24383@techsingularity.net> <20190723120030.GN3419@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20190723120030.GN3419@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 23, 2019 at 02:00:30PM +0200, Peter Zijlstra wrote: > On Tue, Jul 23, 2019 at 12:42:48PM +0100, Mel Gorman wrote: > > On Tue, Jul 23, 2019 at 11:48:30AM +0100, Matt Fleming wrote: > > > Signed-off-by: Matt Fleming > > > Cc: "Suthikulpanit, Suravee" > > > Cc: Mel Gorman > > > Cc: "Lendacky, Thomas" > > > Cc: Borislav Petkov > > > > Acked-by: Mel Gorman > > > > The only caveat I can think of is that a future generation of Zen might > > take a different magic number than 32 as their remote distance. If or > > when this happens, it'll need additional smarts but lacking a crystal > > ball, we can cross that bridge when we come to it. > > I just suggested to Matt on IRC we could do something along these lines, > but we can do that later. > That would seem fair but I do think it's something that could be done later (maybe 1 release away?) to avoid a false bisection to this patch by accident. I don't *think* there are any machines out there with a 1-hop distance of 14 but if there is, your patch would make a difference to MM behaviour. In the same context, it might make sense to rename the value to somewhat reflective of the fact that "reclaim distance" affects scheduler placement. No good name springs to mind at the moment. -- Mel Gorman SUSE Labs