perf scripts python: export-to-postgresql.py: Export switch events

Export switch events to a new table 'context_switches' and create a view
'context_switches_view'. The table and view will show automatically in the
exported-sql-viewer.py script.

If the table ends up empty, then it and the view are dropped.

Signed-off-by: Adrian Hunter <[e-mail]>
Cc: Jiri Olsa <[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

···
 	'last_cstate	integer,'
 	'wake_reason	integer)')
 
+do_query(query, 'CREATE TABLE context_switches ('
+		'id		bigint		NOT NULL,'
+		'machine_id	bigint,'
+		'time		bigint,'
+		'cpu		integer,'
+		'thread_out_id	bigint,'
+		'comm_out_id	bigint,'
+		'thread_in_id	bigint,'
+		'comm_in_id	bigint,'
+		'flags		integer)')
+
 do_query(query, 'CREATE VIEW machines_view AS '
 	'SELECT '
 		'id,'
···
 	' INNER JOIN selected_events ON selected_events.id = samples.evsel_id'
 	' ORDER BY samples.id')
 
+do_query(query, 'CREATE VIEW context_switches_view AS '
+	'SELECT '
+		'context_switches.id,'
+		'context_switches.machine_id,'
+		'context_switches.time,'
+		'context_switches.cpu,'
+		'th_out.pid AS pid_out,'
+		'th_out.tid AS tid_out,'
+		'comm_out.comm AS comm_out,'
+		'th_in.pid AS pid_in,'
+		'th_in.tid AS tid_in,'
+		'comm_in.comm AS comm_in,'
+		'CASE	  WHEN context_switches.flags = 0 THEN \'in\''
+			' WHEN context_switches.flags = 1 THEN \'out\''
+			' WHEN context_switches.flags = 3 THEN \'out preempt\''
+			' ELSE CAST ( context_switches.flags AS VARCHAR(11) )'
+		'END AS flags'
+	' FROM context_switches'
+	' INNER JOIN threads AS th_out ON th_out.id   = context_switches.thread_out_id'
+	' INNER JOIN threads AS th_in  ON th_in.id    = context_switches.thread_in_id'
+	' INNER JOIN comms AS comm_out ON comm_out.id = context_switches.comm_out_id'
+	' INNER JOIN comms AS comm_in  ON comm_in.id  = context_switches.comm_in_id')
+
 file_header = struct.pack("!11sii", b"PGCOPY\n\377\r\n\0", 0, 0)
 file_trailer = b"\377\377"
 
···
 pwre_file		= open_output_file("pwre_table.bin")
 exstop_file		= open_output_file("exstop_table.bin")
 pwrx_file		= open_output_file("pwrx_table.bin")
+context_switches_file	= open_output_file("context_switches_table.bin")
 
 def trace_begin():
 	printdate("Writing to intermediate files...")
···
 	copy_output_file(pwre_file,		"pwre")
 	copy_output_file(exstop_file,		"exstop")
 	copy_output_file(pwrx_file,		"pwrx")
+	copy_output_file(context_switches_file,	"context_switches")
 
 	printdate("Removing intermediate files...")
 	remove_output_file(evsel_file)
···
 	remove_output_file(pwre_file)
 	remove_output_file(exstop_file)
 	remove_output_file(pwrx_file)
+	remove_output_file(context_switches_file)
 	os.rmdir(output_dir_name)
 	printdate("Adding primary keys")
 	do_query(query, 'ALTER TABLE selected_events ADD PRIMARY KEY (id)')
···
 	do_query(query, 'ALTER TABLE pwre            ADD PRIMARY KEY (id)')
 	do_query(query, 'ALTER TABLE exstop          ADD PRIMARY KEY (id)')
 	do_query(query, 'ALTER TABLE pwrx            ADD PRIMARY KEY (id)')
+	do_query(query, 'ALTER TABLE context_switches ADD PRIMARY KEY (id)')
 
 	printdate("Adding foreign keys")
 	do_query(query, 'ALTER TABLE threads '
···
 					'ADD CONSTRAINT idfk        FOREIGN KEY (id)           REFERENCES samples   (id)')
 	do_query(query, 'ALTER TABLE  pwrx '
 					'ADD CONSTRAINT idfk        FOREIGN KEY (id)           REFERENCES samples   (id)')
+	do_query(query, 'ALTER TABLE  context_switches '
+					'ADD CONSTRAINT machinefk   FOREIGN KEY (machine_id)    REFERENCES machines (id),'
+					'ADD CONSTRAINT toutfk      FOREIGN KEY (thread_out_id) REFERENCES threads  (id),'
+					'ADD CONSTRAINT tinfk       FOREIGN KEY (thread_in_id)  REFERENCES threads  (id),'
+					'ADD CONSTRAINT coutfk      FOREIGN KEY (comm_out_id)   REFERENCES comms    (id),'
+					'ADD CONSTRAINT cinfk       FOREIGN KEY (comm_in_id)    REFERENCES comms    (id)')
 
 	printdate("Dropping unused tables")
 	if is_table_empty("ptwrite"):
···
 		drop("pwrx")
 		if is_table_empty("cbr"):
 			drop("cbr")
+	if is_table_empty("context_switches"):
+		drop("context_switches")
 
 	if (unhandled_count):
 		printdate("Warning: ", unhandled_count, " unhandled events")
···
 		pwrx(id, raw_buf)
 	elif config == 5:
 		cbr(id, raw_buf)
+
+def context_switch_table(id, machine_id, time, cpu, thread_out_id, comm_out_id, thread_in_id, comm_in_id, flags, *x):
+	fmt = "!hiqiqiqiiiqiqiqiqii"
+	value = struct.pack(fmt, 9, 8, id, 8, machine_id, 8, time, 4, cpu, 8, thread_out_id, 8, comm_out_id, 8, thread_in_id, 8, comm_in_id, 4, flags)
+	context_switches_file.write(value)