perf script: Update export-to-postgresql to support callchain export

Update the export-to-postgresql.py to support the newly introduced
callchain export.

callchains are added into the existing call_paths table and can now
be associated with samples when the "callpaths" commandline option
is used with the script.

Ex.:

$ perf script -s export-to-postgresql.py example_db all callchains

Includes the following changes to enable callchain export via the python export
APIs:

- Add the "callchains" commandline option, which is used to enable
callchain export by setting the perf_db_export_callchains global
- Add perf_db_export_callchains checks for call_path table creation
and population.
- Add call_path_id to samples_table to conform with the new API

example usage and output using a small test app:

test_app.c:

volatile int x = 0;
void inc_x_loop()
{
int i;
for(i=0; i<100000000; i++)
x++;
}

void a()
{
inc_x_loop();
}

void b()
{
inc_x_loop();
}

int main()
{
a();
b();
return 0;
}

example usage:

$ gcc -g -O0 test_app.c
$ perf record --call-graph=dwarf ./a.out
[ perf record: Woken up 77 times to write data ]
[ perf record: Captured and wrote 19.373 MB perf.data (2404 samples) ]

$ perf script -s scripts/python/export-to-postgresql.py
example_db all callchains

$ psql example_db

example_db=#
SELECT
(SELECT name FROM symbols WHERE id = cps.symbol_id) as symbol,
(SELECT name FROM symbols WHERE id =
(SELECT symbol_id from call_paths where id = cps.parent_id))
as parent_symbol,
sum(period) as event_count
FROM samples join call_paths as cps on call_path_id = cps.id
GROUP BY cps.id,evsel_id
ORDER BY event_count DESC
LIMIT 5;

symbol | parent_symbol | event_count
------------------+--------------------------+-------------
inc_x_loop | a | 734250982
inc_x_loop | b | 731028057
unknown | unknown | 1335858
task_tick_fair | scheduler_tick | 1238842
update_wall_time | tick_do_update_jiffies64 | 650373
(5 rows)

The above data shows total "self time" in cycles for each call path that was
sampled. It is intended to demonstrate how it accounts separately for the two
ways to reach the "inc_x_loop" function(via "a" and "b"). Recursive common
table expressions can be used as well to get cumulative time spent in a
function as well, but that is beyond the scope of this basic example.

Signed-off-by: Chris Phlipot <[e-mail]>
Acked-by: Adrian Hunter <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/scripts/python/export-to-postgresql.py

···
 
 perf_db_export_mode = True
 perf_db_export_calls = False
+perf_db_export_callchains = False
+
 
 def usage():
-	print >> sys.stderr, "Usage is: export-to-postgresql.py <database name> [<columns>] [<calls>]"
+	print >> sys.stderr, "Usage is: export-to-postgresql.py <database name> [<columns>] [<calls>] [<callchains>]"
 	print >> sys.stderr, "where:	columns		'all' or 'branches'"
-	print >> sys.stderr, "		calls		'calls' => create calls table"
+	print >> sys.stderr, "		calls		'calls' => create calls and call_paths table"
+	print >> sys.stderr, "		callchains	'callchains' => create call_paths table"
 	raise Exception("Too few arguments")
 
 if (len(sys.argv) < 2):
···
 
 branches = (columns == "branches")
 
-if (len(sys.argv) >= 4):
-	if (sys.argv[3] == "calls"):
+for i in range(3,len(sys.argv)):
+	if (sys.argv[i] == "calls"):
 		perf_db_export_calls = True
+	elif (sys.argv[i] == "callchains"):
+		perf_db_export_callchains = True
 	else:
 		usage()
 
···
 		'transaction	bigint,'
 		'data_src	bigint,'
 		'branch_type	integer,'
-		'in_tx		boolean)')
+		'in_tx		boolean,'
+		'call_path_id	bigint)')
 
-if perf_db_export_calls:
+if perf_db_export_calls or perf_db_export_callchains:
 	do_query(query, 'CREATE TABLE call_paths ('
 		'id		bigint		NOT NULL,'
 		'parent_id	bigint,'
 		'symbol_id	bigint,'
 		'ip		bigint)')
+if perf_db_export_calls:
 	do_query(query, 'CREATE TABLE calls ('
 		'id		bigint		NOT NULL,'
 		'thread_id	bigint,'
···
 		'(SELECT tid FROM threads WHERE id = thread_id) AS tid'
 	' FROM comm_threads')
 
-if perf_db_export_calls:
+if perf_db_export_calls or perf_db_export_callchains:
 	do_query(query, 'CREATE VIEW call_paths_view AS '
 		'SELECT '
 			'c.id,'
···
 			'(SELECT dso_id FROM symbols WHERE id = p.symbol_id) AS parent_dso_id,'
 			'(SELECT dso FROM symbols_view  WHERE id = p.symbol_id) AS parent_dso_short_name'
 		' FROM call_paths c INNER JOIN call_paths p ON p.id = c.parent_id')
+if perf_db_export_calls:
 	do_query(query, 'CREATE VIEW calls_view AS '
 		'SELECT '
 			'calls.id,'
···
 symbol_file		= open_output_file("symbol_table.bin")
 branch_type_file	= open_output_file("branch_type_table.bin")
 sample_file		= open_output_file("sample_table.bin")
-if perf_db_export_calls:
+if perf_db_export_calls or perf_db_export_callchains:
 	call_path_file		= open_output_file("call_path_table.bin")
+if perf_db_export_calls:
 	call_file		= open_output_file("call_table.bin")
 
 def trace_begin():
···
 	comm_table(0, "unknown")
 	dso_table(0, 0, "unknown", "unknown", "")
 	symbol_table(0, 0, 0, 0, 0, "unknown")
-	sample_table(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
-	if perf_db_export_calls:
+	sample_table(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+	if perf_db_export_calls or perf_db_export_callchains:
 		call_path_table(0, 0, 0, 0)
 
 unhandled_count = 0
···
 	copy_output_file(symbol_file,		"symbols")
 	copy_output_file(branch_type_file,	"branch_types")
 	copy_output_file(sample_file,		"samples")
-	if perf_db_export_calls:
+	if perf_db_export_calls or perf_db_export_callchains:
 		copy_output_file(call_path_file,	"call_paths")
+	if perf_db_export_calls:
 		copy_output_file(call_file,		"calls")
 
 	print datetime.datetime.today(), "Removing intermediate files..."
···
 	remove_output_file(symbol_file)
 	remove_output_file(branch_type_file)
 	remove_output_file(sample_file)
-	if perf_db_export_calls:
+	if perf_db_export_calls or perf_db_export_callchains:
 		remove_output_file(call_path_file)
+	if perf_db_export_calls:
 		remove_output_file(call_file)
 	os.rmdir(output_dir_name)
 	print datetime.datetime.today(), "Adding primary keys"
···
 	do_query(query, 'ALTER TABLE symbols         ADD PRIMARY KEY (id)')
 	do_query(query, 'ALTER TABLE branch_types    ADD PRIMARY KEY (id)')
 	do_query(query, 'ALTER TABLE samples         ADD PRIMARY KEY (id)')
-	if perf_db_export_calls:
+	if perf_db_export_calls or perf_db_export_callchains:
 		do_query(query, 'ALTER TABLE call_paths      ADD PRIMARY KEY (id)')
+	if perf_db_export_calls:
 		do_query(query, 'ALTER TABLE calls           ADD PRIMARY KEY (id)')
 
 	print datetime.datetime.today(), "Adding foreign keys"
···
 					'ADD CONSTRAINT symbolfk   FOREIGN KEY (symbol_id)    REFERENCES symbols    (id),'
 					'ADD CONSTRAINT todsofk    FOREIGN KEY (to_dso_id)    REFERENCES dsos       (id),'
 					'ADD CONSTRAINT tosymbolfk FOREIGN KEY (to_symbol_id) REFERENCES symbols    (id)')
-	if perf_db_export_calls:
+	if perf_db_export_calls or perf_db_export_callchains:
 		do_query(query, 'ALTER TABLE call_paths '
 					'ADD CONSTRAINT parentfk    FOREIGN KEY (parent_id)    REFERENCES call_paths (id),'
 					'ADD CONSTRAINT symbolfk    FOREIGN KEY (symbol_id)    REFERENCES symbols    (id)')
+	if perf_db_export_calls:
 		do_query(query, 'ALTER TABLE calls '
 					'ADD CONSTRAINT threadfk    FOREIGN KEY (thread_id)    REFERENCES threads    (id),'
 					'ADD CONSTRAINT commfk      FOREIGN KEY (comm_id)      REFERENCES comms      (id),'
···
 	value = struct.pack(fmt, 2, 4, branch_type, n, name)
 	branch_type_file.write(value)
 
-def sample_table(sample_id, evsel_id, machine_id, thread_id, comm_id, dso_id, symbol_id, sym_offset, ip, time, cpu, to_dso_id, to_symbol_id, to_sym_offset, to_ip, period, weight, transaction, data_src, branch_type, in_tx, *x):
+def sample_table(sample_id, evsel_id, machine_id, thread_id, comm_id, dso_id, symbol_id, sym_offset, ip, time, cpu, to_dso_id, to_symbol_id, to_sym_offset, to_ip, period, weight, transaction, data_src, branch_type, in_tx, call_path_id, *x):
 	if branches:
-		value = struct.pack("!hiqiqiqiqiqiqiqiqiqiqiiiqiqiqiqiiiB", 17, 8, sample_id, 8, evsel_id, 8, machine_id, 8, thread_id, 8, comm_id, 8, dso_id, 8, symbol_id, 8, sym_offset, 8, ip, 8, time, 4, cpu, 8, to_dso_id, 8, to_symbol_id, 8, to_sym_offset, 8, to_ip, 4, branch_type, 1, in_tx)
+		value = struct.pack("!hiqiqiqiqiqiqiqiqiqiqiiiqiqiqiqiiiBiq", 18, 8, sample_id, 8, evsel_id, 8, machine_id, 8, thread_id, 8, comm_id, 8, dso_id, 8, symbol_id, 8, sym_offset, 8, ip, 8, time, 4, cpu, 8, to_dso_id, 8, to_symbol_id, 8, to_sym_offset, 8, to_ip, 4, branch_type, 1, in_tx, 8, call_path_id)
 	else:
-		value = struct.pack("!hiqiqiqiqiqiqiqiqiqiqiiiqiqiqiqiqiqiqiqiiiB", 21, 8, sample_id, 8, evsel_id, 8, machine_id, 8, thread_id, 8, comm_id, 8, dso_id, 8, symbol_id, 8, sym_offset, 8, ip, 8, time, 4, cpu, 8, to_dso_id, 8, to_symbol_id, 8, to_sym_offset, 8, to_ip, 8, period, 8, weight, 8, transaction, 8, data_src, 4, branch_type, 1, in_tx)
+		value = struct.pack("!hiqiqiqiqiqiqiqiqiqiqiiiqiqiqiqiqiqiqiqiiiBiq", 22, 8, sample_id, 8, evsel_id, 8, machine_id, 8, thread_id, 8, comm_id, 8, dso_id, 8, symbol_id, 8, sym_offset, 8, ip, 8, time, 4, cpu, 8, to_dso_id, 8, to_symbol_id, 8, to_sym_offset, 8, to_ip, 8, period, 8, weight, 8, transaction, 8, data_src, 4, branch_type, 1, in_tx, 8, call_path_id)
 	sample_file.write(value)
 
 def call_path_table(cp_id, parent_id, symbol_id, ip, *x):