From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751795AbaBKKft (ORCPT ); Tue, 11 Feb 2014 05:35:49 -0500 Received: from mail-oa0-f54.google.com ([209.85.219.54]:60572 "EHLO mail-oa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751757AbaBKKfq (ORCPT ); Tue, 11 Feb 2014 05:35:46 -0500 MIME-Version: 1.0 In-Reply-To: <20140211071401.GG27965@twins.programming.kicks-ass.net> References: <1392053356-23024-1-git-send-email-dzickus@redhat.com> <20140210212955.GC5002@laptop.programming.kicks-ass.net> <20140211071401.GG27965@twins.programming.kicks-ass.net> Date: Tue, 11 Feb 2014 11:35:45 +0100 Message-ID: Subject: Re: [PATCH 00/21] perf, c2c: Add new tool to analyze cacheline contention on NUMA systems From: Stephane Eranian To: Peter Zijlstra Cc: Don Zickus , Arnaldo Carvalho de Melo , LKML , Jiri Olsa , Joe Mario , Richard Fowles Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 11, 2014 at 8:14 AM, Peter Zijlstra wrote: > On Mon, Feb 10, 2014 at 11:21:53PM +0100, Stephane Eranian wrote: >> On Mon, Feb 10, 2014 at 10:29 PM, Peter Zijlstra wrote: >> > On Mon, Feb 10, 2014 at 12:28:55PM -0500, Don Zickus wrote: >> >> The data output is verbose and there are lots of data tables that interprit the latencies >> >> and data addresses in different ways to help see where bottlenecks might be lying. >> > >> > Would be good to see what the output looks like. >> > >> > What I haven't seen; and what I would find most useful; is using the IP >> > + dwarf info to map it back to a data structure member. >> > >> > Since you're already using the PEBS data-source fields, you can also >> > have a precise IP. For many cases its possible to reconstruct the exact >> > data member the instruction is modifying. >> > >> The tool already uses precise=2 to get the precise IP. >> >> To get from IP to data member, you'd need some debug info which is not >> yet emitted >> by the compiler. > > That blows; how much is missing? They need to annotate load and stores. I asked for that feature a while ago. It will come.