perf tools: Setup pager when printing usage and help

The --call-graph option is complex so we should provide better guide for users. Also change help message to be consistent with config option names. Now perf top will show help like below:

  $ perf top --call-graph
    Error: option `call-graph' requires a value

Usage: perf top [<options>]

--call-graph <record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]>
setup and enables call-graph (stack chain/backtrace):

record_mode: call graph recording mode (fp|dwarf|lbr)
record_size: if record_mode is 'dwarf', max size of stack recording (<bytes>)
default: 8192 (bytes)
print_type: call graph printing style (graph|flat|fractal|none)
threshold: minimum call graph inclusion threshold (<percent>)
print_limit: maximum number of call graph entry (<number>)
order: call graph order (caller|callee)
sort_key: call graph sort key (function|address)
branch: include last branch info to call graph (branch)

Default: fp,graph,0.5,caller,function

Requested-by Ingo Molnar <[email protected]>

Cc Adrian Hunter <[email protected]>

Cc Borislav Petkov <[email protected]>

Cc Brendan Gregg <[email protected]>

Cc Chandler Carruth <[email protected]>

Cc Frederic Weisbecker <[email protected]>

Cc Stephane Eranian <[email protected]>

Cc Wang Nan <[email protected]>

Signed-off-by Namhyung Kim <[email protected]>

---
 tools/perf/Documentation/perf-record.txt |  9 ++++++--
 tools/perf/Documentation/perf-report.txt | 38 ++++++++++++++++++++------------
 tools/perf/builtin-record.c              |  5 +++--
 tools/perf/builtin-report.c              | 11 +++++----
 tools/perf/builtin-top.c                 |  5 +++--
 tools/perf/util/callchain.h              | 24 +++++++++++++++-----
 6 files changed, 62 insertions(+), 30 deletions(-)

tools/perf/Documentation/perf-record.txt +7 -2

index b027d28658f2..7ff6a9d0ea0d 100644
@@ -144,7 +144,7 @@ OPTIONS
 
 --call-graph::
 	Setup and enable call-graph (stack chain/backtrace) recording,
-	implies -g.
+	implies -g.  Default is "fp".
 
 	Allows specifying "fp" (frame pointer) or "dwarf"
 	(DWARF's CFI - Call Frame Information) or "lbr"

@@ -154,13 +154,18 @@ OPTIONS
 	In some systems, where binaries are build with gcc
 	--fomit-frame-pointer, using the "fp" method will produce bogus
 	call graphs, using "dwarf", if available (perf tools linked to
-	the libunwind library) should be used instead.
+	the libunwind or libdw library) should be used instead.
 	Using the "lbr" method doesn't require any compiler options. It
 	will produce call graphs from the hardware LBR registers. The
 	main limition is that it is only available on new Intel
 	platforms, such as Haswell. It can only get user call chain. It
 	doesn't work with branch stack sampling at the same time.
 
+	When "dwarf" recording is used, perf also records (user) stack dump
+	when sampled.  Default size of the stack dump is 8192 (bytes).
+	User can change the size by passing the size after comma like
+	"--call-graph dwarf,4096".
+
 -q::
 --quiet::
 	Don't print any message, useful for scripting.

tools/perf/Documentation/perf-report.txt +24 -14

index e4fdeeb51123..ab1fd64e3627 100644
@@ -169,30 +169,40 @@ OPTIONS
 --dump-raw-trace::
         Dump raw trace in ASCII.
 
--g [type,min[,limit],order[,key][,branch]]::
---call-graph::
-        Display call chains using type, min percent threshold, optional print
-	limit and order.
-	type can be either:
+-g::
+--call-graph=<print_type,threshold[,print_limit],order,sort_key,branch>::
+        Display call chains using type, min percent threshold, print limit,
+	call order, sort key and branch.  Note that ordering of parameters is not
+	fixed so any parement can be given in an arbitraty order.  One exception
+	is the print_limit which should be preceded by threshold.
+
+	print_type can be either:
 	- flat: single column, linear exposure of call chains.
-	- graph: use a graph tree, displaying absolute overhead rates.
+	- graph: use a graph tree, displaying absolute overhead rates. (default)
 	- fractal: like graph, but displays relative rates. Each branch of
-		 the tree is considered as a new profiled object. +
+		 the tree is considered as a new profiled object.
+	- none: disable call chain display.
+
+	threshold is a percentage value which specifies a minimum percent to be
+	included in the output call graph.  Default is 0.5 (%).
+
+	print_limit is only applied when stdio interface is used.  It's to limit
+	number of call graph entries in a single hist entry.  Note that it needs
+	to be given after threshold (but not necessarily consecutive).
+	Default is 0 (unlimited).
 
 	order can be either:
 	- callee: callee based call graph.
 	- caller: inverted caller based call graph.
+	Default is 'caller' when --children is used, otherwise 'callee'.
 
-	key can be:
-	- function: compare on functions
+	sort_key can be:
+	- function: compare on functions (default)
 	- address: compare on individual code addresses
 
 	branch can be:
-	- branch: include last branch information in callgraph
-	when available. Usually more convenient to use --branch-history
-	for this.
-
-	Default: graph,0.5,caller
+	- branch: include last branch information in callgraph when available.
+	          Usually more convenient to use --branch-history for this.
 
 --children::
 	Accumulate callchain of children to parent entry so that then can

tools/perf/builtin-record.c +3 -2

index 1a117623d396..2740d7a82ae8 100644
@@ -1010,7 +1010,8 @@ static struct record record = {
 	},
 };
 
-const char record_callchain_help[] = CALLCHAIN_RECORD_HELP;
+const char record_callchain_help[] = CALLCHAIN_RECORD_HELP
+	"\n\t\t\t\tDefault: fp";
 
 /*
  * XXX Will stay a global variable till we fix builtin-script.c to stop messing

@@ -1058,7 +1059,7 @@ struct option __record_options[] = {
 			   NULL, "enables call-graph recording" ,
 			   &record_callchain_opt),
 	OPT_CALLBACK(0, "call-graph", &record.opts,
-		     "mode[,dump_size]", record_callchain_help,
+		     "record_mode[,record_size]", record_callchain_help,
 		     &record_parse_callchain_opt),
 	OPT_INCR('v', "verbose", &verbose,
 		    "be more verbose (show counter open errors, etc)"),

tools/perf/builtin-report.c +7 -4

index 545c51cef7f7..50dd4d3d8667 100644
@@ -625,8 +625,11 @@ parse_percent_limit(const struct option *opt, const char *str,
 	return 0;
 }
 
-const char report_callchain_help[] = "Display callchains using " CALLCHAIN_REPORT_HELP ". "
-				     "Default: graph,0.5,caller";
+#define CALLCHAIN_DEFAULT_OPT  "graph,0.5,caller,function"
+
+const char report_callchain_help[] = "Display call graph (stack chain/backtrace):\n\n"
+				     CALLCHAIN_REPORT_HELP
+				     "\n\t\t\t\tDefault: " CALLCHAIN_DEFAULT_OPT;
 
 int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
 {

@@ -636,7 +639,7 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
 	bool has_br_stack = false;
 	int branch_mode = -1;
 	bool branch_call_mode = false;
-	char callchain_default_opt[] = "graph,0.5,caller";
+	char callchain_default_opt[] = CALLCHAIN_DEFAULT_OPT;
 	const char * const report_usage[] = {
 		"perf report [<options>]",
 		NULL

@@ -703,7 +706,7 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
 	OPT_BOOLEAN('x', "exclude-other", &symbol_conf.exclude_other,
 		    "Only display entries with parent-match"),
 	OPT_CALLBACK_DEFAULT('g', "call-graph", &report,
-			     "output_type,min_percent[,print_limit],call_order[,branch]",
+			     "print_type,threshold[,print_limit],order,sort_key[,branch]",
 			     report_callchain_help, &report_parse_callchain_opt,
 			     callchain_default_opt),
 	OPT_BOOLEAN(0, "children", &symbol_conf.cumulate_callchain,

tools/perf/builtin-top.c +3 -2

index af849b1d7389..7e2e72e6d9d1 100644
@@ -1093,7 +1093,8 @@ parse_percent_limit(const struct option *opt, const char *arg,
 	return 0;
 }
 
-const char top_callchain_help[] = CALLCHAIN_RECORD_HELP ", " CALLCHAIN_REPORT_HELP;
+const char top_callchain_help[] = CALLCHAIN_RECORD_HELP CALLCHAIN_REPORT_HELP
+	"\n\t\t\t\tDefault: fp,graph,0.5,caller,function";
 
 int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 {

@@ -1173,7 +1174,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 			   NULL, "enables call-graph recording and display",
 			   &callchain_opt),
 	OPT_CALLBACK(0, "call-graph", &top.record_opts,
-		     "mode[,dump_size],output_type,min_percent[,print_limit],call_order[,branch]",
+		     "record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]",
 		     top_callchain_help, &parse_callchain_opt),
 	OPT_BOOLEAN(0, "children", &symbol_conf.cumulate_callchain,
 		    "Accumulate callchains of children and show total overhead as well"),

tools/perf/util/callchain.h +18 -6

index aaf467c9ef2b..fce8161e54db 100644
@@ -7,17 +7,29 @@
 #include "event.h"
 #include "symbol.h"
 
-#define CALLCHAIN_HELP "setup and enables call-graph (stack chain/backtrace) recording: "
+#define HELP_PAD "\t\t\t\t"
+
+#define CALLCHAIN_HELP "setup and enables call-graph (stack chain/backtrace):\n\n"
 
 #ifdef HAVE_DWARF_UNWIND_SUPPORT
-#define CALLCHAIN_RECORD_HELP  CALLCHAIN_HELP "fp dwarf lbr"
+# define RECORD_MODE_HELP  HELP_PAD "record_mode:\tcall graph recording mode (fp|dwarf|lbr)\n"
 #else
-#define CALLCHAIN_RECORD_HELP  CALLCHAIN_HELP "fp lbr"
+# define RECORD_MODE_HELP  HELP_PAD "record_mode:\tcall graph recording mode (fp|lbr)\n"
 #endif
 
-#define CALLCHAIN_REPORT_HELP  "output_type (graph, flat, fractal, or none), " \
-	"min percent threshold, optional print limit, callchain order, " \
-	"key (function or address), add branches"
+#define RECORD_SIZE_HELP						\
+	HELP_PAD "record_size:\tif record_mode is 'dwarf', max size of stack recording (<bytes>)\n" \
+	HELP_PAD "\t\tdefault: 8192 (bytes)\n"
+
+#define CALLCHAIN_RECORD_HELP  CALLCHAIN_HELP RECORD_MODE_HELP RECORD_SIZE_HELP
+
+#define CALLCHAIN_REPORT_HELP						\
+	HELP_PAD "print_type:\tcall graph printing style (graph|flat|fractal|none)\n" \
+	HELP_PAD "threshold:\tminimum call graph inclusion threshold (<percent>)\n" \
+	HELP_PAD "print_limit:\tmaximum number of call graph entry (<number>)\n" \
+	HELP_PAD "order:\t\tcall graph order (caller|callee)\n" \
+	HELP_PAD "sort_key:\tcall graph sort key (function|address)\n"	\
+	HELP_PAD "branch:\t\tinclude last branch info to call graph (branch)\n"
 
 enum perf_call_graph_mode {
 	CALLCHAIN_NONE,

Signature · 1 line

2.6.0

Em Thu, Oct 22, 2015 at 11:28:32PM +0900, Namhyung Kim escreveu:

Quoted 22 lines

The --call-graph option is complex so we should provide better guide for users. Also change help message to be consistent with config option names. Now perf top will show help like below:

  $ perf top --call-graph
    Error: option `call-graph' requires a value

Usage: perf top [<options>]

--call-graph <record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]>
setup and enables call-graph (stack chain/backtrace):

record_mode: call graph recording mode (fp|dwarf|lbr)
record_size: if record_mode is 'dwarf', max size of stack recording (<bytes>)
default: 8192 (bytes)
print_type: call graph printing style (graph|flat|fractal|none)
threshold: minimum call graph inclusion threshold (<percent>)
print_limit: maximum number of call graph entry (<number>)
order: call graph order (caller|callee)
sort_key: call graph sort key (function|address)
branch: include last branch info to call graph (branch)

Quoted 1 line

Default: fp,graph,0.5,caller,function

At some point it would be nice to be able to use:

        perf top --call-graph caller

And have that be equivalent to:

        perf top --callgraph fp,graph,0.5,caller,function

I.e. change just one of the defaults.

But I think that how you did it is backwards compatible, i.e. adding stuff just to the end.

Ah, noticed you forgot to update the 'top' man page

Quoted 236 lines

Requested-by Ingo Molnar <[email protected]>

Cc Adrian Hunter <[email protected]>

Cc Borislav Petkov <[email protected]>

Cc Brendan Gregg <[email protected]>

Cc Chandler Carruth <[email protected]>

Cc Frederic Weisbecker <[email protected]>

Cc Stephane Eranian <[email protected]>

Cc Wang Nan <[email protected]>

Signed-off-by Namhyung Kim <[email protected]>

---
 tools/perf/Documentation/perf-record.txt |  9 ++++++--
 tools/perf/Documentation/perf-report.txt | 38 ++++++++++++++++++++------------
 tools/perf/builtin-record.c              |  5 +++--
 tools/perf/builtin-report.c              | 11 +++++----
 tools/perf/builtin-top.c                 |  5 +++--
 tools/perf/util/callchain.h              | 24 +++++++++++++++-----
 6 files changed, 62 insertions(+), 30 deletions(-)

tools/perf/Documentation/perf-record.txt +7 -2

index b027d28658f2..7ff6a9d0ea0d 100644
@@ -144,7 +144,7 @@ OPTIONS
 
 --call-graph::
      Setup and enable call-graph (stack chain/backtrace) recording,
-     implies -g.
+     implies -g.  Default is "fp".
 
      Allows specifying "fp" (frame pointer) or "dwarf"
      (DWARF's CFI - Call Frame Information) or "lbr"

@@ -154,13 +154,18 @@ OPTIONS
      In some systems, where binaries are build with gcc
      --fomit-frame-pointer, using the "fp" method will produce bogus
      call graphs, using "dwarf", if available (perf tools linked to
-     the libunwind library) should be used instead.
+     the libunwind or libdw library) should be used instead.
      Using the "lbr" method doesn't require any compiler options. It
      will produce call graphs from the hardware LBR registers. The
      main limition is that it is only available on new Intel
      platforms, such as Haswell. It can only get user call chain. It
      doesn't work with branch stack sampling at the same time.
 
+     When "dwarf" recording is used, perf also records (user) stack dump
+     when sampled.  Default size of the stack dump is 8192 (bytes).
+     User can change the size by passing the size after comma like
+     "--call-graph dwarf,4096".
+
 -q::
 --quiet::
      Don't print any message, useful for scripting.

tools/perf/Documentation/perf-report.txt +24 -14

index e4fdeeb51123..ab1fd64e3627 100644
@@ -169,30 +169,40 @@ OPTIONS
 --dump-raw-trace::
         Dump raw trace in ASCII.
 
--g [type,min[,limit],order[,key][,branch]]::
---call-graph::
-        Display call chains using type, min percent threshold, optional print
-     limit and order.
-     type can be either:
+-g::
+--call-graph=<print_type,threshold[,print_limit],order,sort_key,branch>::
+        Display call chains using type, min percent threshold, print limit,
+     call order, sort key and branch.  Note that ordering of parameters is not
+     fixed so any parement can be given in an arbitraty order.  One exception
+     is the print_limit which should be preceded by threshold.
+
+     print_type can be either:
      - flat: single column, linear exposure of call chains.
-     - graph: use a graph tree, displaying absolute overhead rates.
+     - graph: use a graph tree, displaying absolute overhead rates. (default)
      - fractal: like graph, but displays relative rates. Each branch of
-              the tree is considered as a new profiled object. +
+              the tree is considered as a new profiled object.
+     - none: disable call chain display.
+
+     threshold is a percentage value which specifies a minimum percent to be
+     included in the output call graph.  Default is 0.5 (%).
+
+     print_limit is only applied when stdio interface is used.  It's to limit
+     number of call graph entries in a single hist entry.  Note that it needs
+     to be given after threshold (but not necessarily consecutive).
+     Default is 0 (unlimited).
 
      order can be either:
      - callee: callee based call graph.
      - caller: inverted caller based call graph.
+     Default is 'caller' when --children is used, otherwise 'callee'.
 
-     key can be:
-     - function: compare on functions
+     sort_key can be:
+     - function: compare on functions (default)
      - address: compare on individual code addresses
 
      branch can be:
-     - branch: include last branch information in callgraph
-     when available. Usually more convenient to use --branch-history
-     for this.
-
-     Default: graph,0.5,caller
+     - branch: include last branch information in callgraph when available.
+               Usually more convenient to use --branch-history for this.
 
 --children::
      Accumulate callchain of children to parent entry so that then can

tools/perf/builtin-record.c +3 -2

index 1a117623d396..2740d7a82ae8 100644
@@ -1010,7 +1010,8 @@ static struct record record = {
      },
 };
 
-const char record_callchain_help[] = CALLCHAIN_RECORD_HELP;
+const char record_callchain_help[] = CALLCHAIN_RECORD_HELP
+     "\n\t\t\t\tDefault: fp";
 
 /*
  * XXX Will stay a global variable till we fix builtin-script.c to stop messing

@@ -1058,7 +1059,7 @@ struct option __record_options[] = {
                         NULL, "enables call-graph recording" ,
                         &record_callchain_opt),
      OPT_CALLBACK(0, "call-graph", &record.opts,
-                  "mode[,dump_size]", record_callchain_help,
+                  "record_mode[,record_size]", record_callchain_help,
                   &record_parse_callchain_opt),
      OPT_INCR('v', "verbose", &verbose,
                  "be more verbose (show counter open errors, etc)"),

tools/perf/builtin-report.c +7 -4

index 545c51cef7f7..50dd4d3d8667 100644
@@ -625,8 +625,11 @@ parse_percent_limit(const struct option *opt, const char *str,
      return 0;
 }
 
-const char report_callchain_help[] = "Display callchains using " CALLCHAIN_REPORT_HELP ". "
-                                  "Default: graph,0.5,caller";
+#define CALLCHAIN_DEFAULT_OPT  "graph,0.5,caller,function"
+
+const char report_callchain_help[] = "Display call graph (stack chain/backtrace):\n\n"
+                                  CALLCHAIN_REPORT_HELP
+                                  "\n\t\t\t\tDefault: " CALLCHAIN_DEFAULT_OPT;
 
 int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
 {

@@ -636,7 +639,7 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
      bool has_br_stack = false;
      int branch_mode = -1;
      bool branch_call_mode = false;
-     char callchain_default_opt[] = "graph,0.5,caller";
+     char callchain_default_opt[] = CALLCHAIN_DEFAULT_OPT;
      const char * const report_usage[] = {
              "perf report [<options>]",
              NULL

@@ -703,7 +706,7 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
      OPT_BOOLEAN('x', "exclude-other", &symbol_conf.exclude_other,
                  "Only display entries with parent-match"),
      OPT_CALLBACK_DEFAULT('g', "call-graph", &report,
-                          "output_type,min_percent[,print_limit],call_order[,branch]",
+                          "print_type,threshold[,print_limit],order,sort_key[,branch]",
                           report_callchain_help, &report_parse_callchain_opt,
                           callchain_default_opt),
      OPT_BOOLEAN(0, "children", &symbol_conf.cumulate_callchain,

tools/perf/builtin-top.c +3 -2

index af849b1d7389..7e2e72e6d9d1 100644
@@ -1093,7 +1093,8 @@ parse_percent_limit(const struct option *opt, const char *arg,
      return 0;
 }
 
-const char top_callchain_help[] = CALLCHAIN_RECORD_HELP ", " CALLCHAIN_REPORT_HELP;
+const char top_callchain_help[] = CALLCHAIN_RECORD_HELP CALLCHAIN_REPORT_HELP
+     "\n\t\t\t\tDefault: fp,graph,0.5,caller,function";
 
 int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 {

@@ -1173,7 +1174,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
                         NULL, "enables call-graph recording and display",
                         &callchain_opt),
      OPT_CALLBACK(0, "call-graph", &top.record_opts,
-                  "mode[,dump_size],output_type,min_percent[,print_limit],call_order[,branch]",
+                  "record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]",
                   top_callchain_help, &parse_callchain_opt),
      OPT_BOOLEAN(0, "children", &symbol_conf.cumulate_callchain,
                  "Accumulate callchains of children and show total overhead as well"),

tools/perf/util/callchain.h +18 -7

index aaf467c9ef2b..fce8161e54db 100644
@@ -7,17 +7,29 @@
 #include "event.h"
 #include "symbol.h"
 
-#define CALLCHAIN_HELP "setup and enables call-graph (stack chain/backtrace) recording: "
+#define HELP_PAD "\t\t\t\t"
+
+#define CALLCHAIN_HELP "setup and enables call-graph (stack chain/backtrace):\n\n"
 
 #ifdef HAVE_DWARF_UNWIND_SUPPORT
-#define CALLCHAIN_RECORD_HELP  CALLCHAIN_HELP "fp dwarf lbr"
+# define RECORD_MODE_HELP  HELP_PAD "record_mode:\tcall graph recording mode (fp|dwarf|lbr)\n"
 #else
-#define CALLCHAIN_RECORD_HELP  CALLCHAIN_HELP "fp lbr"
+# define RECORD_MODE_HELP  HELP_PAD "record_mode:\tcall graph recording mode (fp|lbr)\n"
 #endif
 
-#define CALLCHAIN_REPORT_HELP  "output_type (graph, flat, fractal, or none), " \
-     "min percent threshold, optional print limit, callchain order, " \
-     "key (function or address), add branches"
+#define RECORD_SIZE_HELP                                             \
+     HELP_PAD "record_size:\tif record_mode is 'dwarf', max size of stack recording (<bytes>)\n" \
+     HELP_PAD "\t\tdefault: 8192 (bytes)\n"
+
+#define CALLCHAIN_RECORD_HELP  CALLCHAIN_HELP RECORD_MODE_HELP RECORD_SIZE_HELP
+
+#define CALLCHAIN_REPORT_HELP                                                \
+     HELP_PAD "print_type:\tcall graph printing style (graph|flat|fractal|none)\n" \
+     HELP_PAD "threshold:\tminimum call graph inclusion threshold (<percent>)\n" \
+     HELP_PAD "print_limit:\tmaximum number of call graph entry (<number>)\n" \
+     HELP_PAD "order:\t\tcall graph order (caller|callee)\n" \
+     HELP_PAD "sort_key:\tcall graph sort key (function|address)\n"  \
+     HELP_PAD "branch:\t\tinclude last branch info to call graph (branch)\n"
 
 enum perf_call_graph_mode {
      CALLCHAIN_NONE,
--

2.6.0

On Thu, Oct 22, 2015 at 11:46 PM, Arnaldo Carvalho de Melo

Quoted 4 lines

At some point it would be nice to be able to use:

        perf top --call-graph caller

Quoted 5 lines

And have that be equivalent to:

        perf top --callgraph fp,graph,0.5,caller,function

I.e. change just one of the defaults.

?? That's supported already by commit e8232f1ad468 ("perf report:
Relax -g option parsing not to limit the option order")..

Quoted 4 lines

But I think that how you did it is backwards compatible, i.e. adding stuff just to the end.

Ah, noticed you forgot to update the 'top' man page

Heh, I just added below in the previous patch.. ;-)

"See --call-graph section in perf-record and perf-report man pages for details."

Thanks,
Namhyung

/me goes to bed now...

The --call-graph option is complex so we should provide better guide for users. Also change help message to be consistent with config option names. Now perf top will show help like below:

  $ perf top --call-graph
    Error: option `call-graph' requires a value

Usage: perf top [<options>]

--call-graph <record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]>
setup and enables call-graph (stack chain/backtrace):

record_mode: call graph recording mode (fp|dwarf|lbr)
record_size: if record_mode is 'dwarf', max size of stack recording (<bytes>)
default: 8192 (bytes)
print_type: call graph printing style (graph|flat|fractal|none)
threshold: minimum call graph inclusion threshold (<percent>)
print_limit: maximum number of call graph entry (<number>)
order: call graph order (caller|callee)
sort_key: call graph sort key (function|address)
branch: include last branch info to call graph (branch)

Default: fp,graph,0.5,caller,function

The --call-graph option is complex so we should provide better guide for users. Also change help message to be consistent with config option names. Now perf top will show help like below:

  $ perf top --call-graph
    Error: option `call-graph' requires a value

Usage: perf top [<options>]

--call-graph <record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]>
setup and enables call-graph (stack chain/backtrace):

record_mode: call graph recording mode (fp|dwarf|lbr)
record_size: if record_mode is 'dwarf', max size of stack recording (<bytes>)
default: 8192 (bytes)
print_type: call graph printing style (graph|flat|fractal|none)
threshold: minimum call graph inclusion threshold (<percent>)
print_limit: maximum number of call graph entry (<number>)
order: call graph order (caller|callee)
sort_key: call graph sort key (function|address)
branch: include last branch info to call graph (branch)

Default: fp,graph,0.5,caller,function

Commit-ID:  76a26549eb367f683fbb394b7246bef5dc665f8c
Gitweb:     http://git.kernel.org/tip/76a26549eb367f683fbb394b7246bef5dc665f8c
Author:     Namhyung Kim <[email protected]>
AuthorDate: Thu, 22 Oct 2015 23:28:32 +0900
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Thu, 22 Oct 2015 16:23:19 -0300

perf tools: Improve call graph documents and help messages

The --call-graph option is complex so we should provide better guide for users. Also change help message to be consistent with config option names. Now perf top will show help like below:

  $ perf top --call-graph
    Error: option `call-graph' requires a value

Usage: perf top [<options>]

--call-graph <record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]>
setup and enables call-graph (stack chain/backtrace):

record_mode: call graph recording mode (fp|dwarf|lbr)
record_size: if record_mode is 'dwarf', max size of stack recording (<bytes>)
default: 8192 (bytes)
print_type: call graph printing style (graph|flat|fractal|none)
threshold: minimum call graph inclusion threshold (<percent>)
print_limit: maximum number of call graph entry (<number>)
order: call graph order (caller|callee)
sort_key: call graph sort key (function|address)
branch: include last branch info to call graph (branch)

Quoted 21 lines · tip-bot for Namhyung Kim

Commit-ID:  76a26549eb367f683fbb394b7246bef5dc665f8c
Gitweb:     http://git.kernel.org/tip/76a26549eb367f683fbb394b7246bef5dc665f8c
Author:     Namhyung Kim <[email protected]>
AuthorDate: Thu, 22 Oct 2015 23:28:32 +0900
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Thu, 22 Oct 2015 16:23:19 -0300

perf tools: Improve call graph documents and help messages

The --call-graph option is complex so we should provide better guide for users. Also change help message to be consistent with config option names. Now perf top will show help like below:

  $ perf top --call-graph
    Error: option `call-graph' requires a value

Usage: perf top [<options>]

--call-graph <record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]>
setup and enables call-graph (stack chain/backtrace):

Quoted 9 lines

record_mode: call graph recording mode (fp|dwarf|lbr)
record_size: if record_mode is 'dwarf', max size of stack recording (<bytes>)
default: 8192 (bytes)
print_type: call graph printing style (graph|flat|fractal|none)
threshold: minimum call graph inclusion threshold (<percent>)
print_limit: maximum number of call graph entry (<number>)
order: call graph order (caller|callee)
sort_key: call graph sort key (function|address)
branch: include last branch info to call graph (branch)

Btw., how is the last line to be interpreted? Is the 'branch' value 0/1? If yes then the text should probably say so? Or does the string 'branch' have to be used?

Hi Ingo,

Quoted 34 lines · Ingo Molnar

Quoted 30 lines · tip-bot for Namhyung Kim

Commit-ID:  76a26549eb367f683fbb394b7246bef5dc665f8c
Gitweb:     http://git.kernel.org/tip/76a26549eb367f683fbb394b7246bef5dc665f8c
Author:     Namhyung Kim <[email protected]>
AuthorDate: Thu, 22 Oct 2015 23:28:32 +0900
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Thu, 22 Oct 2015 16:23:19 -0300

perf tools: Improve call graph documents and help messages

The --call-graph option is complex so we should provide better guide for users. Also change help message to be consistent with config option names. Now perf top will show help like below:

  $ perf top --call-graph
    Error: option `call-graph' requires a value

Usage: perf top [<options>]

--call-graph <record_mode[,record_size],print_type,threshold[,print_limit],order,sort_key[,branch]>
setup and enables call-graph (stack chain/backtrace):

record_mode: call graph recording mode (fp|dwarf|lbr)
record_size: if record_mode is 'dwarf', max size of stack recording (<bytes>)
default: 8192 (bytes)
print_type: call graph printing style (graph|flat|fractal|none)
threshold: minimum call graph inclusion threshold (<percent>)
print_limit: maximum number of call graph entry (<number>)
order: call graph order (caller|callee)
sort_key: call graph sort key (function|address)
branch: include last branch info to call graph (branch)

Quoted 2 lines

Btw., how is the last line to be interpreted? Is the 'branch' value 0/1? If yes then the text should probably say so? Or does the string 'branch' have to be used?

Yep, the string 'branch' should be used.

It's annoying to see error or help message when command has many options like in perf record, report or top. So setup pager when print parser error or help message - it should be OK since no UI is enabled at the parsing time. The usage_with_options() already disables it by calling exit_browser() anyway.

Cc Adrian Hunter <[email protected]>

Cc Borislav Petkov <[email protected]>

Cc Brendan Gregg <[email protected]>

Cc Chandler Carruth <[email protected]>

Cc Frederic Weisbecker <[email protected]>

Cc Stephane Eranian <[email protected]>

Cc Wang Nan <[email protected]>

Signed-off-by Namhyung Kim <[email protected]>

---
 tools/perf/util/parse-options.c | 2 ++
 1 file changed, 2 insertions(+)

tools/perf/util/parse-options.c +2 -0

index 8aa7922397a9..388d385df5ad 100644
@@ -648,6 +648,8 @@ int usage_with_options_internal(const char * const *usagestr,
 	if (!usagestr)
 		return PARSE_OPT_HELP;
 
+	setup_pager();
+
 	fprintf(stderr, "\n Usage: %s\n", *usagestr++);
 	while (*usagestr && **usagestr)
 		fprintf(stderr, "    or: %s\n", *usagestr++);

Signature · 1 line

2.6.0

Em Thu, Oct 22, 2015 at 11:28:31PM +0900, Namhyung Kim escreveu:

Quoted 5 lines

It's annoying to see error or help message when command has many options like in perf record, report or top. So setup pager when print parser error or help message - it should be OK since no UI is enabled at the parsing time. The usage_with_options() already disables it by calling exit_browser() anyway.

But then we don't know what went wrong, try:

[acme@zoo linux]$ perf record --all-cpus -g --42 --event cycles 2>&1 | head
Error: unknown option `42'

Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]

-e, --event <event> event selector. use 'perf list' to list
available events
--filter <filter>
event filter
--exclude-perf don't record events from perf itself
-p, --pid <pid> record events on existing process id
[acme@zoo linux]$

Without this patch I can see what was the option that caused the problem (--42 in this case), after the patch I can see only the valid options, not the one causing the problem, well, I can see it only if I use the same 2>&1 technique above.

Quoted 27 lines

Cc Adrian Hunter <[email protected]>

Cc Borislav Petkov <[email protected]>

Cc Brendan Gregg <[email protected]>

Cc Chandler Carruth <[email protected]>

Cc Frederic Weisbecker <[email protected]>

Cc Stephane Eranian <[email protected]>

Cc Wang Nan <[email protected]>

Signed-off-by Namhyung Kim <[email protected]>

---
 tools/perf/util/parse-options.c | 2 ++
 1 file changed, 2 insertions(+)

tools/perf/util/parse-options.c +2 -1

index 8aa7922397a9..388d385df5ad 100644
@@ -648,6 +648,8 @@ int usage_with_options_internal(const char * const *usagestr,
      if (!usagestr)
              return PARSE_OPT_HELP;
 
+     setup_pager();
+
      fprintf(stderr, "\n Usage: %s\n", *usagestr++);
      while (*usagestr && **usagestr)
              fprintf(stderr, "    or: %s\n", *usagestr++);
--

2.6.0