Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753334AbaKRHz5 (ORCPT ); Tue, 18 Nov 2014 02:55:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49321 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751417AbaKRHz4 (ORCPT ); Tue, 18 Nov 2014 02:55:56 -0500 Date: Tue, 18 Nov 2014 08:55:39 +0100 From: Jiri Olsa To: Namhyung Kim Cc: "Liang, Kan" , "acme@kernel.org" , "a.p.zijlstra@chello.nl" , "eranian@google.com" , "linux-kernel@vger.kernel.org" , "mingo@redhat.com" , "paulus@samba.org" , "ak@linux.intel.com" Subject: Re: [PATCH V3 3/3] perf tools: Construct LBR call chain Message-ID: <20141118075539.GA27645@krava.brq.redhat.com> References: <1415972652-17310-1-git-send-email-kan.liang@intel.com> <1415972652-17310-4-git-send-email-kan.liang@intel.com> <20141117155425.GA31042@krava.brq.redhat.com> <37D7C6CF3E00A74B8858931C1DB2F07701670BF9@SHSMSX103.ccr.corp.intel.com> <87lhn9qbmp.fsf@sejong.aot.lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87lhn9qbmp.fsf@sejong.aot.lge.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 18, 2014 at 03:13:50PM +0900, Namhyung Kim wrote: SNIP > >> > + * in "from" register, while the callee is stored > >> > + * in "to" register. > >> > + * For example, there is a call stack > >> > + * "A"->"B"->"C"->"D". > >> > + * The LBR registers will recorde like > >> > + * "C"->"D", "B"->"C", "A"->"B". > >> > + * So only the first "to" register and all "from" > >> > + * registers are needed to construct the whole > >> stack. > >> > + */ > >> > >> Andi is using some sanity checks: > >> http://marc.info/?l=linux-kernel&m=141584447819894&w=2 > >> I guess this could be applied in here, once his patch gets in. > >> > > > > Are you suggesting me to remove the comments, > > or rebase the whole patch to Andi's patch once it's merged? > > > > The branch history in Andi's patch is different as the call stack, > > although they are both from LBR. > > Andi's branch history recording branch records for > > taken branches, interrupts, and exceptions. > > While the LBR call stack records for the call stack. > > Right. And branch history can overlap with normal callchains so > additional check in there is to remove duplication. While LBR call > stack is separated to user only so there should be no overlap. hum, it seemed to me like the remove_loops function could be used for this one as well.. but anyway I meant that this can be introduced later after Andi's change gets in thanks, jirka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/