Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751291AbaBKK6v (ORCPT ); Tue, 11 Feb 2014 05:58:51 -0500 Received: from mail-oa0-f54.google.com ([209.85.219.54]:39371 "EHLO mail-oa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750758AbaBKK6r (ORCPT ); Tue, 11 Feb 2014 05:58:47 -0500 MIME-Version: 1.0 In-Reply-To: <20140211105217.GS9987@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> <20140211105217.GS9987@twins.programming.kicks-ass.net> Date: Tue, 11 Feb 2014 11:58:45 +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 11:52 AM, Peter Zijlstra wrote: > On Tue, Feb 11, 2014 at 11:35:45AM +0100, Stephane Eranian wrote: >> On Tue, Feb 11, 2014 at 8:14 AM, Peter Zijlstra wrote: >> > >> > That blows; how much is missing? >> >> They need to annotate load and stores. I asked for that feature a while ago. >> It will come. > > And there is no way to deduce the information? We have type information > for all arguments and local variables, right? So we can follow that. > > struct foo { > int ponies; > int moar_ponies; > }; > > struct bar { > int my_ponies; > struct foo *foo; > }; > > int moo(struct bar *bar) > { > return bar->foo->moar_ponies; > } > > Since we have the argument type, we can find the type for both loads, > the first load: > > *bar+8, we know is: struct foo * bar::foo > *foo+4, we know is: int foo::moar_ponies > > Or am I missing something? How do you know that load at addr 0x1000 is accessing variable bar? The IP gives you line number, and then what? I think dwarf has the mapping regs -> variable and yes, the type info. But I am not sure that's enough. -- 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/