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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,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 99EBDC43382 for ; Wed, 26 Sep 2018 06:06:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5595B2089D for ; Wed, 26 Sep 2018 06:06:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5595B2089D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com 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 S1727010AbeIZMRi (ORCPT ); Wed, 26 Sep 2018 08:17:38 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:56702 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726355AbeIZMRi (ORCPT ); Wed, 26 Sep 2018 08:17:38 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w8Q5wcT8072711 for ; Wed, 26 Sep 2018 02:06:23 -0400 Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) by mx0a-001b2d01.pphosted.com with ESMTP id 2mr1d0eq4d-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 26 Sep 2018 02:06:22 -0400 Received: from localhost by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 26 Sep 2018 00:06:17 -0600 Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w8Q66Gei25034780 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 25 Sep 2018 23:06:16 -0700 Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B8D616A054; Wed, 26 Sep 2018 00:06:16 -0600 (MDT) Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6BDBA6A04F; Wed, 26 Sep 2018 00:06:16 -0600 (MDT) Received: from sofia.ibm.com (unknown [9.124.35.106]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP; Wed, 26 Sep 2018 00:06:16 -0600 (MDT) Received: by sofia.ibm.com (Postfix, from userid 1000) id 3B1AB2E3D69; Wed, 26 Sep 2018 11:36:13 +0530 (IST) Date: Wed, 26 Sep 2018 11:36:13 +0530 From: Gautham R Shenoy To: Dave Hansen Cc: ego@linux.vnet.ibm.com, "Aneesh Kumar K.V" , Srikar Dronamraju , Michael Ellerman , Benjamin Herrenschmidt , Michael Neuling , Vaidyanathan Srinivasan , Akshay Adiga , Shilpasri G Bhat , "Oliver O'Halloran" , Nicholas Piggin , Murilo Opsfelder Araujo , Anton Blanchard , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 0/3] powerpc: Detection and scheduler optimization for POWER9 bigcore Reply-To: ego@linux.vnet.ibm.com References: <1537464159-25919-1-git-send-email-ego@linux.vnet.ibm.com> <133c7bca-5720-81de-7956-b93870a1bab8@intel.com> <20180922110340.GA1402@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-TM-AS-GCONF: 00 x-cbid: 18092606-0004-0000-0000-00001491E4CC X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009773; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000267; SDB=6.01093778; UDB=6.00565348; IPR=6.00873816; MB=3.00023509; MTD=3.00000008; XFM=3.00000015; UTC=2018-09-26 06:06:20 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18092606-0005-0000-0000-000088F12FD5 Message-Id: <20180926060613.GA22139@in.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-09-26_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1809260062 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Dave, On Tue, Sep 25, 2018 at 03:16:30PM -0700, Dave Hansen wrote: > On 09/22/2018 04:03 AM, Gautham R Shenoy wrote: > > Without this patchset, the SMT domain would be defined as the group of > > threads that share L2 cache. > > Could you try to make a more clear, concise statement about the current > state of the art vs. what you want it to be? Right now, the sched > domains do something like this in terms of ordering: > > 1. SMT siblings > 2. Caches > 3. NUMA Yes. you are right. The state of art on POWER9 machines having SMT8 cores is as you described above with 1. SMT siblings sharing L2-cache, called the SMT domain 2. Cores on the same die, called the DIE domain 3. NUMA > > It sounds like you don't want SMT siblings to be the things that we use, > right? Because some siblings share caches and some do not. Right? You > want something like this: > > 1. SMT siblings (sharing L1) > 2. SMT siblings (sharing L2) > 3. Other caches > 4. NUMA > Yes, with the patchset the sched-domain hierarchy on POWER9 machines having SMT8 will be: 1. SMT siblings sharing L1 cache, called the SMT domain 2. SMT siblings sharing L2 cache, called the CACHE domain (introduced in commit 96d91431d691 "powerpc/smp: Add Power9 scheduler topology") 3. Cores on the same die, called the DIE domain. 4. NUMA -- Thanks and Regards gautham.