From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752736AbdJLHwD convert rfc822-to-8bit (ORCPT ); Thu, 12 Oct 2017 03:52:03 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46690 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751410AbdJLHwC (ORCPT ); Thu, 12 Oct 2017 03:52:02 -0400 From: Stewart Smith To: Anju T Sudhakar , Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, maddy@linux.vnet.ibm.com, hemant@linux.vnet.ibm.com Subject: Re: [PATCH] powerpc/powernv: Add kernel cmdline parameter to disable imc In-Reply-To: <06fe39eb-d5fe-4472-56b4-f66390d7fad9@linux.vnet.ibm.com> References: <1507531597-25947-1-git-send-email-anju@linux.vnet.ibm.com> <87wp43wf2v.fsf@concordia.ellerman.id.au> <87infmeonf.fsf@linux.vnet.ibm.com> <06fe39eb-d5fe-4472-56b4-f66390d7fad9@linux.vnet.ibm.com> Date: Thu, 12 Oct 2017 18:51:51 +1100 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-TM-AS-GCONF: 00 x-cbid: 17101207-0020-0000-0000-00000CD6A21A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007883; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000236; SDB=6.00929967; UDB=6.00468107; IPR=6.00710234; BA=6.00005634; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017503; XFM=3.00000015; UTC=2017-10-12 07:52:00 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17101207-0021-0000-0000-00005E7B5427 Message-Id: <87sheoby7c.fsf@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-12_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710120112 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Anju T Sudhakar writes: > On Wednesday 11 October 2017 01:55 AM, Stewart Smith wrote: >> Michael Ellerman writes: >>> Anju T Sudhakar writes: >>> >>>> Add a kernel command line parameter option to disable In-Memory Collection >>>> (IMC) counters and add documentation. This helps in debug. >>> I'd really rather we didn't. Do we *really* need this? >>> >>> We don't have command line parameters to disable any of the other ~20 >>> PMUs, why is this one special? > > This one is really helpful in debugging, incase if we want to proceed > without nest counters  OR > core counters . But if we have the facility to do the same from > petitboot, its fine. https://patchwork.ozlabs.org/patch/824497/ (skiboot patch) should do the same thing, right? That means we come up with them off (as we should have from the start) and if you don't use the PMUs then the ucode won't be started. -- Stewart Smith OPAL Architect, IBM.