Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753142Ab2KGHil (ORCPT ); Wed, 7 Nov 2012 02:38:41 -0500 Received: from LGEMRELSE7Q.lge.com ([156.147.1.151]:51338 "EHLO LGEMRELSE7Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751053Ab2KGHik convert rfc822-to-8bit (ORCPT ); Wed, 7 Nov 2012 02:38:40 -0500 X-AuditID: 9c930197-b7c0bae00000042f-82-509a0ffdedfa From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Stephane Eranian , linux-kernel@vger.kernel.org, Andi Kleen , Masami Hiramatsu , Peter Zijlstra , Jiri Olsa , Ingo Molnar Subject: Re: [PATCH v2 00/16] perf: add memory access sampling support References: <1352123463-7346-1-git-send-email-eranian@google.com> <20121106205220.GF13629@infradead.org> Date: Wed, 07 Nov 2012 16:38:36 +0900 In-Reply-To: <20121106205220.GF13629@infradead.org> (Arnaldo Carvalho de Melo's message of "Tue, 6 Nov 2012 17:52:21 -0300") Message-ID: <87fw4looar.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1942 Lines: 40 Hi Arnaldo, On Tue, 6 Nov 2012 17:52:21 -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Nov 05, 2012 at 02:50:47PM +0100, Stephane Eranian escreveu: > [root@sandy acme]# perf mem -t load rep --stdio --sort=symbol,symbol_daddr,cost > # Samples: 30 of event 'cpu/mem-loads/pp' > # Total cost : 640 > # Sort order : symbol,symbol_daddr,cost > # > # Overhead Samples Symbol Data Symbol Cost > # ........ ........... ...................... ...................... ....... > # > 55.00% 1 [k] lookup_fast [k] 0xffff8803b7521bd4 352 > 5.47% 1 [k] cache_alloc_refill [k] 0xffff880407705024 35 > 3.44% 1 [k] cache_alloc_refill [k] 0xffff88041d8527d8 22 > 3.28% 1 [k] run_timer_softirq [k] 0xffff88041e2c3e90 21 > 2.50% 1 [k] __list_add [k] 0xffff8803b7521d68 16 > 2.19% 1 [.] __strcoll_l [.] 0x00007fffa8d44080 14 > 1.88% 1 [.] __strcoll_l [.] 0x00007fffa8d44104 12 > > If we go to the annotation browser to see where is that lookup_fast hitting we get: > > 100.00 │ mov -0x34(%rbp),%eax > > How to map 0xffff8803b7521bd4 to a stack variable, struct members and all? > > Humm, for userspace we have PERF_SAMPLE_REGS_USER for the dwarf unwinder we > need for userspace, but what about reverse mapping of kernel variables? Jiri? I suspect there aren't much thing we can do on stack. One thing we can do is adding dso_daddr to sort key and seeing it's a [stack] (or [stack:tid]) or not. But not sure it can be done for kernel stacks too. Thanks, Namhyung -- 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/