Explain 'call-graph' section and its variables. 'record-mode', 'dump-size', 'print-type', 'order', 'sort-key', 'threshold' and 'print-limit'.
Cc: Namhyung Kim <[email protected]> Cc: Jiri Olsa <[email protected]> Signed-off-by: Taeung Song <[email protected]> --- 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 129efb1..d20a80c 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'. + 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. + + 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. + + 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 + + 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 (%). + + 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. + 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
