From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753138AbdJLIFq (ORCPT ); Thu, 12 Oct 2017 04:05:46 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:52425 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751632AbdJLIFp (ORCPT ); Thu, 12 Oct 2017 04:05:45 -0400 Subject: Re: [PATCH] powerpc/powernv: Add kernel cmdline parameter to disable imc To: Stewart Smith , Anju T Sudhakar , Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, hemant@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> <87sheoby7c.fsf@linux.vnet.ibm.com> From: Madhavan Srinivasan Date: Thu, 12 Oct 2017 13:35:05 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <87sheoby7c.fsf@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-TM-AS-MML: disable x-cbid: 17101208-0012-0000-0000-000005810D88 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17101208-0013-0000-0000-000018FB2038 Message-Id: <69dfcb10-2d7d-f6d3-3bb6-34ef6676b6b1@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=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710120115 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 12 October 2017 01:21 PM, Stewart Smith wrote: > 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, Thats right. With that skiboot patch, IMC will be paused at start.