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=-2.2 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT 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 20F03C433F5 for ; Fri, 31 Aug 2018 12:06:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDAF020661 for ; Fri, 31 Aug 2018 12:06:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ZgERnTxB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CDAF020661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728176AbeHaQOH (ORCPT ); Fri, 31 Aug 2018 12:14:07 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:56530 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727486AbeHaQOG (ORCPT ); Fri, 31 Aug 2018 12:14:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; 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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=qY5Q/tlww02APwr/szGcOdf/zkUT24XZ5KGNKMGWr98=; b=ZgERnTxBbKCZBkfB+W+u2xkbI nGOvqgQKM9fbvYMGv6tqOWQjUiTeVlOkZr7VCfE8vS7pebbKbu1dZtH5n1c41vF531uvVzFju/G8S QTgG3Kywi2i+rEJgGKedhrWwm7Wv2PlyVdNDnZR6yAz/fZyeV3W+z5mfM3b3wS3Qp2A1mRjI1rhNq 2F1x1nY6nGDxUJon1ymmJQhIXRZvCdSVhm2qeq/X8PztpfKpW6X2d8Bti00S4Baq+LJX6d3BWM7pM 8eqaJlUCIq0IIZgGVFyYJVunSrv13nB747kCO5w30jEaa1URmhG8qUim6XkqdpEEFXPd1gnT/S7cm 5SCk2ZrUg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fviCE-0000et-3y; Fri, 31 Aug 2018 12:06:38 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4F4F42024D700; Fri, 31 Aug 2018 14:06:36 +0200 (CEST) Date: Fri, 31 Aug 2018 14:06:36 +0200 From: Peter Zijlstra To: Srikar Dronamraju Cc: Ingo Molnar , LKML , Mel Gorman , Rik van Riel , Thomas Gleixner , Michael Ellerman , Heiko Carstens , Suravee Suthikulpanit , linuxppc-dev , Andre Wild , Benjamin Herrenschmidt Subject: Re: [PATCH] sched/topology: Use Identity node only if required Message-ID: <20180831120636.GM24124@hirez.programming.kicks-ass.net> References: <1533712172-11428-1-git-send-email-srikar@linux.vnet.ibm.com> <20180808075840.GO2494@hirez.programming.kicks-ass.net> <20180810164533.GB42350@linux.vnet.ibm.com> <20180829084348.GO24124@hirez.programming.kicks-ass.net> <20180831102248.GA8437@linux.vnet.ibm.com> <20180831104115.GH24124@hirez.programming.kicks-ass.net> <20180831112618.GA10911@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180831112618.GA10911@linux.vnet.ibm.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 31, 2018 at 04:56:18PM +0530, Srikar Dronamraju wrote: > This was the same in my previous posting too. Before the topology update > happened, all the cpus would be in SMT, DIE. The topology updates can be > disabled using a kernel parameter topology_updates=off. Its documented under > https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html as > > topology_updates= [KNL, PPC, NUMA] Format: {off} Specify if the kernel > should ignore (off) topology updates sent by the hypervisor to this > LPAR. > > and is not something new in powerpc. Doesn't mean it isn't utterly broken.