Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933755AbcLVHYn (ORCPT ); Thu, 22 Dec 2016 02:24:43 -0500 Received: from out02.mta.xmission.com ([166.70.13.232]:52840 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750804AbcLVHYm (ORCPT ); Thu, 22 Dec 2016 02:24:42 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Hari Bathini Cc: Peter Zijlstra , ast@fb.com, lkml , acme@kernel.org, alexander.shishkin@linux.intel.com, mingo@redhat.com, daniel@iogearbox.net, rostedt@goodmis.org, Ananth N Mavinakayanahalli , sargun@sargun.me, Aravinda Prasad , brendan.d.gregg@gmail.com References: <148182699546.5314.279803283347257825.stgit@hbathini.in.ibm.com> <148182702692.5314.556699668213767056.stgit@hbathini.in.ibm.com> <20161215184646.GP3107@twins.programming.kicks-ass.net> <20161216075703.GE3124@twins.programming.kicks-ass.net> <2c0e3bbb-90a1-b5a4-b6d4-19c419ef5411@linux.vnet.ibm.com> <20161216200536.GI3124@twins.programming.kicks-ass.net> <1702a267-0ce6-86da-7755-11a375e450e2@linux.vnet.ibm.com> <20161221132452.GT3124@twins.programming.kicks-ass.net> <2af6cd8b-46f3-b60d-581f-30269ea65d53@linux.vnet.ibm.com> Date: Thu, 22 Dec 2016 20:21:23 +1300 In-Reply-To: <2af6cd8b-46f3-b60d-581f-30269ea65d53@linux.vnet.ibm.com> (Hari Bathini's message of "Wed, 21 Dec 2016 21:26:12 +0530") Message-ID: <87d1gkig3w.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1cJxjx-0004XA-Ru;;;mid=<87d1gkig3w.fsf@xmission.com>;;;hst=in01.mta.xmission.com;;;ip=101.100.131.98;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+9KDp2IUDnoa3nA1VpaExxBmslK3f3uy0= X-SA-Exim-Connect-IP: 101.100.131.98 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4876] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Hari Bathini X-Spam-Relay-Country: X-Spam-Timing: total 873 ms - load_scoreonly_sql: 0.06 (0.0%), signal_user_changed: 4.8 (0.6%), b_tie_ro: 3.2 (0.4%), parse: 1.43 (0.2%), extract_message_metadata: 4.4 (0.5%), get_uri_detail_list: 1.81 (0.2%), tests_pri_-1000: 5 (0.6%), tests_pri_-950: 1.86 (0.2%), tests_pri_-900: 1.52 (0.2%), tests_pri_-400: 27 (3.1%), check_bayes: 26 (2.9%), b_tokenize: 9 (1.0%), b_tok_get_all: 8 (0.9%), b_comp_prob: 2.7 (0.3%), b_tok_touch_all: 3.3 (0.4%), b_finish: 0.86 (0.1%), tests_pri_0: 811 (92.8%), check_dkim_signature: 0.58 (0.1%), check_dkim_adsp: 3.4 (0.4%), tests_pri_500: 3.9 (0.4%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH v4 1/3] perf: add PERF_RECORD_NAMESPACES to include namespaces related info X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1289 Lines: 31 Hari Bathini writes: > On Wednesday 21 December 2016 06:54 PM, Peter Zijlstra wrote: >> On Wed, Dec 21, 2016 at 06:39:01PM +0530, Hari Bathini wrote: >>> Hi Peter, >>>> I don't see how the tool can parse old records (with NAMESPACES_MAX == >>>> 7) if you set its NAMESPACES_MAX to say 10. >>>> >>>> Then it will expect the link_info array to be 10 entries and either read >>>> past the end of the record (if !sample_all) or try and interpret >>>> sample_id as link_info records. >>>> >>> Right. There will be inconsistency with data the perf tool tries to read >>> beyond >>> what the kernel supports. IIUC, you mean, include nr_namespaces field in the >>> record and warn the user if it doesn't match with the one perf-tool supports >>> before proceeding..? >> Yes, if you add a nr_namespaces field its always parsable. If an old >> tool finds more namespace than it has 'names' for it can always display >> the raw index number. If a new tool finds the array short, it will not >> display the missing ones. >> > > Sure, Peter. Will post the next version as soon as > I am back from vacation.. And please make the array the last item in the structure so that expanding or contracting it does not affect the ability to read the rest of the structure. Eric