From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752327AbeEPPWd (ORCPT ); Wed, 16 May 2018 11:22:33 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:54048 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752285AbeEPPWa (ORCPT ); Wed, 16 May 2018 11:22:30 -0400 From: Stewart Smith To: Akshay Adiga , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: Akshay Adiga , npiggin@gmail.com, ego@linux.vnet.ibm.com Subject: Re: [PATCH] cpuidle/powernv : init all present cpus for deep states In-Reply-To: <1526472134-23757-1-git-send-email-akshay.adiga@linux.vnet.ibm.com> References: <1526472134-23757-1-git-send-email-akshay.adiga@linux.vnet.ibm.com> Date: Wed, 16 May 2018 10:22:22 -0500 MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 x-cbid: 18051615-0008-0000-0000-000009CB0593 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009035; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000260; SDB=6.01033180; UDB=6.00528261; IPR=6.00812311; MB=3.00021147; MTD=3.00000008; XFM=3.00000015; UTC=2018-05-16 15:22:27 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18051615-0009-0000-0000-0000474DBD3D Message-Id: <87efiby6a9.fsf@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-05-16_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805160154 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Akshay Adiga writes: > Init all present cpus for deep states instead of "all possible" cpus. > Init fails if the possible cpu is gaurded. Resulting in making only > non-deep states available for cpuidle/hotplug. Should this also head to stable? It means that for single threaded workloads, if you guard out a CPU core you'll not get WoF, which means that performance goes down when you wouldn't expect it to. Right? -- Stewart Smith OPAL Architect, IBM.