Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965251AbcLVKWm (ORCPT ); Thu, 22 Dec 2016 05:22:42 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:33259 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S939007AbcLVKWk (ORCPT ); Thu, 22 Dec 2016 05:22:40 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Peter Zijlstra Cc: Hari Bathini , 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: <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> <87d1gkig3w.fsf@xmission.com> <20161222075327.GV3124@twins.programming.kicks-ass.net> Date: Thu, 22 Dec 2016 23:19:17 +1300 In-Reply-To: <20161222075327.GV3124@twins.programming.kicks-ass.net> (Peter Zijlstra's message of "Thu, 22 Dec 2016 08:53:27 +0100") Message-ID: <87r350gtay.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=1cK0W7-0005Hg-5T;;;mid=<87r350gtay.fsf@xmission.com>;;;hst=in01.mta.xmission.com;;;ip=101.100.131.98;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/sm/cailttm3gQMuatz3NZPZuF2CmBYCU= 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. * -0.0 BAYES_40 BODY: Bayes spam probability is 20 to 40% * [score: 0.2063] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa03 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa03 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Peter Zijlstra X-Spam-Relay-Country: X-Spam-Timing: total 5558 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 4.0 (0.1%), b_tie_ro: 2.7 (0.0%), parse: 1.25 (0.0%), extract_message_metadata: 26 (0.5%), get_uri_detail_list: 1.16 (0.0%), tests_pri_-1000: 8 (0.2%), tests_pri_-950: 2.0 (0.0%), tests_pri_-900: 1.66 (0.0%), tests_pri_-400: 29 (0.5%), check_bayes: 28 (0.5%), b_tokenize: 10 (0.2%), b_tok_get_all: 7 (0.1%), b_comp_prob: 3.7 (0.1%), b_tok_touch_all: 3.2 (0.1%), b_finish: 0.91 (0.0%), tests_pri_0: 749 (13.5%), check_dkim_signature: 0.82 (0.0%), check_dkim_adsp: 4.5 (0.1%), tests_pri_500: 4731 (85.1%), poll_dns_idle: 4722 (85.0%), 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: 663 Lines: 21 Peter Zijlstra writes: > On Thu, Dec 22, 2016 at 08:21:23PM +1300, Eric W. Biederman wrote: >> >> 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. > > Sorry, sample_id must be last, because hysterical crud :/ > > (basically because that was the only way to add a field to records like > PERF_RECORD_MMAP which used the record length to determine the > filename[] length, yes I know, we won't ever do that again). Why does historical crud need to affect new records? Totally confused. This looks like a major mess. Eric