Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752708AbbK3FEK (ORCPT ); Mon, 30 Nov 2015 00:04:10 -0500 Received: from mail-pa0-f46.google.com ([209.85.220.46]:35393 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750917AbbK3FEH (ORCPT ); Mon, 30 Nov 2015 00:04:07 -0500 Date: Mon, 30 Nov 2015 14:03:35 +0900 From: Namhyung Kim To: Taeung Song Cc: Arnaldo Carvalho de Melo , "linux-kernel@vger.kernel.org" , Ingo Molnar , Jiri Olsa Subject: Re: [PATCH v11 10/24] perf config: Document variables for 'call-graph' section in man page Message-ID: <20151130050335.GA19219@danjae.kornet> References: <1447768424-17327-1-git-send-email-treeze.taeung@gmail.com> <1447768424-17327-10-git-send-email-treeze.taeung@gmail.com> <20151118025104.GI7062@sejong> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 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: 5709 Lines: 170 On Mon, Nov 30, 2015 at 10:42:00AM +0900, Taeung Song wrote: > Hi, Namhyung Hi Taeung, > > On Nov 18, 2015, at 11:51 AM, Namhyung Kim wrote: > > > > On Tue, Nov 17, 2015 at 10:53:30PM +0900, Taeung Song wrote: > >> Explain 'call-graph' section and its variables. > >> > >> 'record-mode', 'dump-size', 'print-type', 'order', > >> 'sort-key', 'threshold' and 'print-limit'. > >> > >> Cc: Namhyung Kim > >> Cc: Jiri Olsa > >> Signed-off-by: Taeung Song > >> --- > >> tools/perf/Documentation/perf-config.txt | 65 ++++++++++++++++++++++++++++++++ > >> 1 file changed, 65 insertions(+) > >> > >> diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt > >> index 7d386d4..dc659d6 100644 > >> --- a/tools/perf/Documentation/perf-config.txt > >> +++ b/tools/perf/Documentation/perf-config.txt > >> @@ -285,6 +285,71 @@ ui.*:: > >> There're columns as header 'Overhead', 'Children', 'Shared Object', 'Symbol', 'self'. > >> If this option is false, they are hiden. This option is only applied to TUI. > >> > >> +call-graph.*:: > >> + When sub-commands 'top' and 'report' work with -g/—-children > >> + there're options in control of call-graph. > >> + > >> + call-graph.record-mode:: > >> + The record-mode can be 'fp' (frame pointer) and 'dwarf'. > > > > Also 'lbr' can be used, but it only work for recent intel cpus. > > > > > >> + The value of 'dwarf' is effective only if perf detect needed library > >> + (libunwind or a recent version of libdw). Also it doesn't *require* > >> + the dump-size option since it can use the default value of 8192 if > >> + missing. > > > > I think the last sentence can be omitted. > > > > > >> + > >> + call-graph.dump-size:: > >> + The size of stack to dump in order to do post-unwinding. Default is 8192 (byte). > >> + When using dwarf into record-mode this option should have a value. > > > > This contradicts the above, it'll use the default size if omitted. > > > > > >> + > >> + call-graph.print-type:: > >> + The print-types can be graph (graph absolute), fractal (graph relative), flat. The 'folded' print type was added recently. Please update it too. > >> + This option controls a way to show overhead for each callchain entry. > >> + Suppose a following example. > >> + > >> + Overhead Symbols > >> + ........ ....... > >> + 40.00% foo > >> + | > >> + --- foo > >> + | > >> + |--50.00%-- bar > >> + | main > >> + | > >> + --50.00%-- baz > >> + main > > > > ^ > > it needs one more whitespace > > > > I checked this patch file and whitespace and tab characters on it. > But I think the lacking whitespace because of mail client. > After 'make install’ I checked it but there is no lack of whitespace. > Are there different problems that I missed ? I meant whitespace in the callchain graph (i.e. 'bar' and 'baz' should be aligned). But I think I was wrong - it should look like below: Overhead Symbols ........ ....... 40.00% foo | ---foo | |--50.00%--bar | main | --50.00%--baz main Maybe it's because you used TAB characters for indent? Thanks, Namhyung > > > > >> + > >> + This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly > >> + half and half so 'fractal' shows 50.00% for each > >> + (meaning that it assumes 100% total overhead of 'foo'). > >> + > >> + The 'graph' uses absolute overhead value of 'foo' as total so each of > >> + 'bar' and 'baz' callchain will have 20.00% of overhead. > >> + > >> + call-graph.order:: > >> + This option controls print order of callchains. The default is > >> + 'callee' which means callee is printed at top and then followed by its > >> + caller and so on. The 'caller' prints it in reverse order. > >> + > >> + If this option is not set and report.children or top.children is > >> + set to true (or the equivalent command line option is given), > >> + the default value of this option is changed to 'caller' for the > >> + execution of 'perf report' or 'perf top'. Other commands will > >> + still default to 'callee'. > >> + > >> + call-graph.sort-key:: > >> + The callchains are merged if they contain same information. > >> + The sort-key option determines a way to compare the callchains. > >> + A value of 'sort-key' can be 'function' or 'address'. > >> + The default is 'function'. > >> + > >> + call-graph.threshold:: > >> + When there're many callchains it'd print tons of lines. So perf omits > >> + small callchains under a certain overhead (threshold) and this option > >> + control the threashold. Default is 0.5 (%). > > > > s/threashold/threshold/ > > > > Also it'd be better to mention that the overhead is calculated by > > value depends on call-graph.print-type. > > > > > >> + > >> + call-graph.print-limit:: > >> + This is another way to control the number of callchains printed for a > >> + single entry. Default is 0 which means no limitation. > > > > This is a maximum number of lines of callchain printed for a single > > histogram entry. > > > > Thanks, > > Namhyung > > > > > >> + > >> SEE ALSO > >> -------- > >> linkperf:perf[1] > >> -- > >> 1.9.1 > -- 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/