[PATCH 07/25] perf tools: Add more documentation to export-to-postgresql.py script

From: Adrian Hunter
Date: Fri Sep 25 2015 - 09:23:46 EST


Add some comments to the script and some 'views' to the created
database that better illustrate the database structure and how it
can be used.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/scripts/python/export-to-postgresql.py | 221 ++++++++++++++++++++++
1 file changed, 221 insertions(+)

diff --git a/tools/perf/scripts/python/export-to-postgresql.py b/tools/perf/scripts/python/export-to-postgresql.py
index 84a32037a80f..1b02cdc0cab6 100644
--- a/tools/perf/scripts/python/export-to-postgresql.py
+++ b/tools/perf/scripts/python/export-to-postgresql.py
@@ -61,6 +61,142 @@ import datetime
#
# An example of using the database is provided by the script
# call-graph-from-postgresql.py. Refer to that script for details.
+#
+# Tables:
+#
+# The tables largely correspond to perf tools' data structures. They are largely self-explanatory.
+#
+# samples
+#
+# 'samples' is the main table. It represents what instruction was executing at a point in time
+# when something (a selected event) happened. The memory address is the instruction pointer or 'ip'.
+#
+# calls
+#
+# 'calls' represents function calls and is related to 'samples' by 'call_id' and 'return_id'.
+# 'calls' is only created when the 'calls' option to this script is specified.
+#
+# call_paths
+#
+# 'call_paths' represents all the call stacks. Each 'call' has an associated record in 'call_paths'.
+# 'calls_paths' is only created when the 'calls' option to this script is specified.
+#
+# branch_types
+#
+# 'branch_types' provides descriptions for each type of branch.
+#
+# comm_threads
+#
+# 'comm_threads' shows how 'comms' relates to 'threads'.
+#
+# comms
+#
+# 'comms' contains a record for each 'comm' - the name given to the executable that is running.
+#
+# dsos
+#
+# 'dsos' contains a record for each executable file or library.
+#
+# machines
+#
+# 'machines' can be used to distinguish virtual machines if virtualization is supported.
+#
+# selected_events
+#
+# 'selected_events' contains a record for each kind of event that has been sampled.
+#
+# symbols
+#
+# 'symbols' contains a record for each symbol. Only symbols that have samples are present.
+#
+# threads
+#
+# 'threads' contains a record for each thread.
+#
+# Views:
+#
+# Most of the tables have views for more friendly display. The views are:
+#
+# calls_view
+# call_paths_view
+# comm_threads_view
+# dsos_view
+# machines_view
+# samples_view
+# symbols_view
+# threads_view
+#
+# More examples of browsing the database with psql:
+# Note that some of the examples are not the most optimal SQL query.
+# Note that call information is only available if the script's 'calls' option has been used.
+#
+# Top 10 function calls (not aggregated by symbol):
+#
+# SELECT * FROM calls_view ORDER BY elapsed_time DESC LIMIT 10;
+#
+# Top 10 function calls (aggregated by symbol):
+#
+# SELECT symbol_id,(SELECT name FROM symbols WHERE id = symbol_id) AS symbol,
+# SUM(elapsed_time) AS tot_elapsed_time,SUM(branch_count) AS tot_branch_count
+# FROM calls_view GROUP BY symbol_id ORDER BY tot_elapsed_time DESC LIMIT 10;
+#
+# Note that the branch count gives a rough estimation of cpu usage, so functions
+# that took a long time but have a relatively low branch count must have spent time
+# waiting.
+#
+# Find symbols by pattern matching on part of the name (e.g. names containing 'alloc'):
+#
+# SELECT * FROM symbols_view WHERE name LIKE '%alloc%';
+#
+# Top 10 function calls for a specific symbol (e.g. whose symbol_id is 187):
+#
+# SELECT * FROM calls_view WHERE symbol_id = 187 ORDER BY elapsed_time DESC LIMIT 10;
+#
+# Show function calls made by function in the same context (i.e. same call path) (e.g. one with call_path_id 254):
+#
+# SELECT * FROM calls_view WHERE parent_call_path_id = 254;
+#
+# Show branches made during a function call (e.g. where call_id is 29357 and return_id is 29370 and tid is 29670)
+#
+# SELECT * FROM samples_view WHERE id >= 29357 AND id <= 29370 AND tid = 29670 AND event LIKE 'branches%';
+#
+# Show transactions:
+#
+# SELECT * FROM samples_view WHERE event = 'transactions';
+#
+# Note transaction start has 'in_tx' true whereas, transaction end has 'in_tx' false.
+# Transaction aborts have branch_type_name 'transaction abort'
+#
+# Show transaction aborts:
+#
+# SELECT * FROM samples_view WHERE event = 'transactions' AND branch_type_name = 'transaction abort';
+#
+# To print a call stack requires walking the call_paths table. For example this python script:
+# #!/usr/bin/python2
+#
+# import sys
+# from PySide.QtSql import *
+#
+# if __name__ == '__main__':
+# if (len(sys.argv) < 3):
+# print >> sys.stderr, "Usage is: printcallstack.py <database name> <call_path_id>"
+# raise Exception("Too few arguments")
+# dbname = sys.argv[1]
+# call_path_id = sys.argv[2]
+# db = QSqlDatabase.addDatabase('QPSQL')
+# db.setDatabaseName(dbname)
+# if not db.open():
+# raise Exception("Failed to open database " + dbname + " error: " + db.lastError().text())
+# query = QSqlQuery(db)
+# print " id ip symbol_id symbol dso_id dso_short_name"
+# while call_path_id != 0 and call_path_id != 1:
+# ret = query.exec_('SELECT * FROM call_paths_view WHERE id = ' + str(call_path_id))
+# if not ret:
+# raise Exception("Query failed: " + query.lastError().text())
+# if not query.next():
+# raise Exception("Query failed")
+# print "{0:>6} {1:>10} {2:>9} {3:<30} {4:>6} {5:<30}".format(query.value(0), query.value(1), query.value(2), query.value(3), query.value(4), query.value(5))
+# call_path_id = query.value(6)

from PySide.QtSql import *

@@ -244,6 +380,91 @@ if perf_db_export_calls:
'parent_call_path_id bigint,'
'flags integer)')

+do_query(query, 'CREATE VIEW machines_view AS '
+ 'SELECT '
+ 'id,'
+ 'pid,'
+ 'root_dir,'
+ 'CASE WHEN id=0 THEN \'unknown\' WHEN pid=-1 THEN \'host\' ELSE \'guest\' END AS host_or_guest'
+ ' FROM machines')
+
+do_query(query, 'CREATE VIEW dsos_view AS '
+ 'SELECT '
+ 'id,'
+ 'machine_id,'
+ '(SELECT host_or_guest FROM machines_view WHERE id = machine_id) AS host_or_guest,'
+ 'short_name,'
+ 'long_name,'
+ 'build_id'
+ ' FROM dsos')
+
+do_query(query, 'CREATE VIEW symbols_view AS '
+ 'SELECT '
+ 'id,'
+ 'name,'
+ '(SELECT short_name FROM dsos WHERE id=dso_id) AS dso,'
+ 'dso_id,'
+ 'sym_start,'
+ 'sym_end,'
+ 'CASE WHEN binding=0 THEN \'local\' WHEN binding=1 THEN \'global\' ELSE \'weak\' END AS binding'
+ ' FROM symbols')
+
+do_query(query, 'CREATE VIEW threads_view AS '
+ 'SELECT '
+ 'id,'
+ 'machine_id,'
+ '(SELECT host_or_guest FROM machines_view WHERE id = machine_id) AS host_or_guest,'
+ 'process_id,'
+ 'pid,'
+ 'tid'
+ ' FROM threads')
+
+do_query(query, 'CREATE VIEW comm_threads_view AS '
+ 'SELECT '
+ 'comm_id,'
+ '(SELECT comm FROM comms WHERE id = comm_id) AS command,'
+ 'thread_id,'
+ '(SELECT pid FROM threads WHERE id = thread_id) AS pid,'
+ '(SELECT tid FROM threads WHERE id = thread_id) AS tid'
+ ' FROM comm_threads')
+
+if perf_db_export_calls:
+ do_query(query, 'CREATE VIEW call_paths_view AS '
+ 'SELECT '
+ 'c.id,'
+ 'to_hex(c.ip) AS ip,'
+ 'c.symbol_id,'
+ '(SELECT name FROM symbols WHERE id = c.symbol_id) AS symbol,'
+ '(SELECT dso_id FROM symbols WHERE id = c.symbol_id) AS dso_id,'
+ '(SELECT dso FROM symbols_view WHERE id = c.symbol_id) AS dso_short_name,'
+ 'c.parent_id,'
+ 'to_hex(p.ip) AS parent_ip,'
+ 'p.symbol_id AS parent_symbol_id,'
+ '(SELECT name FROM symbols WHERE id = p.symbol_id) AS parent_symbol,'
+ '(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')
+ do_query(query, 'CREATE VIEW calls_view AS '
+ 'SELECT '
+ 'calls.id,'
+ 'thread_id,'
+ '(SELECT pid FROM threads WHERE id = thread_id) AS pid,'
+ '(SELECT tid FROM threads WHERE id = thread_id) AS tid,'
+ '(SELECT comm FROM comms WHERE id = comm_id) AS command,'
+ 'call_path_id,'
+ 'to_hex(ip) AS ip,'
+ 'symbol_id,'
+ '(SELECT name FROM symbols WHERE id = symbol_id) AS symbol,'
+ 'call_time,'
+ 'return_time,'
+ 'return_time - call_time AS elapsed_time,'
+ 'branch_count,'
+ 'call_id,'
+ 'return_id,'
+ 'CASE WHEN flags=1 THEN \'no call\' WHEN flags=2 THEN \'no return\' WHEN flags=3 THEN \'no call/return\' ELSE \'\' END AS flags,'
+ 'parent_call_path_id'
+ ' FROM calls INNER JOIN call_paths ON call_paths.id = call_path_id')
+
do_query(query, 'CREATE VIEW samples_view AS '
'SELECT '
'id,'
--
1.9.1

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