From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752852AbdATP4r (ORCPT ); Fri, 20 Jan 2017 10:56:47 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46460 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752495AbdATP4p (ORCPT ); Fri, 20 Jan 2017 10:56:45 -0500 Subject: Re: [PATCH v5 1/3] perf: add PERF_RECORD_NAMESPACES to include namespaces related info To: Peter Zijlstra References: <148466259095.32153.10361763951552633449.stgit@hbathini.in.ibm.com> <148466262903.32153.14129217679474433212.stgit@hbathini.in.ibm.com> <20170118142608.GF6515@twins.programming.kicks-ass.net> Cc: ast@fb.com, lkml , acme@kernel.org, alexander.shishkin@linux.intel.com, mingo@redhat.com, daniel@iogearbox.net, rostedt@goodmis.org, Ananth N Mavinakayanahalli , ebiederm@xmission.com, sargun@sargun.me, Aravinda Prasad , brendan.d.gregg@gmail.com, jolsa@redhat.com From: Hari Bathini Date: Fri, 20 Jan 2017 21:26:32 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20170118142608.GF6515@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17012015-1617-0000-0000-0000019E851E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17012015-1618-0000-0000-00004796D60F Message-Id: <4019acf2-357d-af5d-a44c-414128e3033c@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-01-20_11:,, 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=8.0.1-1612050000 definitions=main-1701200215 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter, On Wednesday 18 January 2017 07:56 PM, Peter Zijlstra wrote: > On Tue, Jan 17, 2017 at 07:47:22PM +0530, Hari Bathini wrote: >> With the advert of container technologies like docker, that depend >> on namespaces for isolation, there is a need for tracing support for >> namespaces. This patch introduces new PERF_RECORD_NAMESPACES event >> for tracing based on namespaces related info. > This fails to mention the whole namespace of namespaces issue Eric IIUC, Eric wanted to have device info saved for each namespace separately to avoid the need for a namespace of namespaces in future. > brought up. Where are we on that, and or why isn't it required? I did address that in v4 and haven't changed it in v5. I am not sure if it needs any mentioning in the changelog.. >> +/* >> + * The maximum size of the name of each namespace >> + */ >> +#define NS_NAME_SIZE 8 >> + >> +struct perf_ns_link_info { >> + char name[NS_NAME_SIZE]; > Do we really need a name? why? Helps print new namespaces info along with name without any changes in perf tool. Avoids hard-coding names too.. Thanks Hari