Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752296AbbK3BmJ (ORCPT ); Sun, 29 Nov 2015 20:42:09 -0500 Received: from mail-pa0-f47.google.com ([209.85.220.47]:34425 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751675AbbK3BmG convert rfc822-to-8bit (ORCPT ); Sun, 29 Nov 2015 20:42:06 -0500 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.0 \(3094\)) Subject: Re: [PATCH v11 10/24] perf config: Document variables for 'call-graph' section in man page From: Taeung Song In-Reply-To: <20151118025104.GI7062@sejong> Date: Mon, 30 Nov 2015 10:42:00 +0900 Cc: Arnaldo Carvalho de Melo , "linux-kernel@vger.kernel.org" , Ingo Molnar , Jiri Olsa Content-Transfer-Encoding: 8BIT Message-Id: References: <1447768424-17327-1-git-send-email-treeze.taeung@gmail.com> <1447768424-17327-10-git-send-email-treeze.taeung@gmail.com> <20151118025104.GI7062@sejong> To: Namhyung Kim X-Mailer: Apple Mail (2.3094) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4855 Lines: 144 Hi, Namhyung > 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. >> + 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 ? Thanks, Taeung > >> + >> + 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/