Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933180AbbKRIss (ORCPT ); Wed, 18 Nov 2015 03:48:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58009 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932299AbbKRIsq (ORCPT ); Wed, 18 Nov 2015 03:48:46 -0500 Date: Wed, 18 Nov 2015 09:48:42 +0100 From: Jiri Olsa To: "Wangnan (F)" Cc: Jiri Olsa , Arnaldo Carvalho de Melo , David Ahern , Peter Zijlstra , Ingo Molnar , Milian Wolff , linux-kernel@vger.kernel.org, pi3orama , lizefan 00213767 Subject: Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Message-ID: <20151118084842.GA10182@krava.brq.redhat.com> References: <564C26C4.2040603@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <564C26C4.2040603@huawei.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1656 Lines: 59 On Wed, Nov 18, 2015 at 03:20:36PM +0800, Wangnan (F) wrote: SNIP > > Then use perf to trace it: > > # ./pref record -g -F 9 --call-graph dwarf ./test_dwarf_unwind > # ./perf report --no-children --stdio > ... > 1.23% test_dwarf_unwi test_dwarf_unwind [.] funcc > | > ---funcc > | > |--0.62%-- funcb > | funca > | main > | __libc_start_main > | _start > | > --0.62%-- 0 <-- I applied Jiri's patch in [1] so see this > 0, > which indicates a broken call chain. can't see this case after multiple running your test, just the 'end-of-the-callchain' zeros 49.14% test_dwarf_unwi [vdso] [.] __vdso_gettimeofday | ---__vdso_gettimeofday funcc funcb funca main __libc_start_main _start 0 40.78% test_dwarf_unwi [vdso] [.] 0x0000000000000987 | ---0x7ffe28ab7987 __vdso_gettimeofday funcc funcb funca main __libc_start_main _start 0 what kernel do you have? 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/