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 <[email protected]>
Cc: Jiri Olsa <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Now that a thread's current comm is exported, it shows up in the call graph
and call tree even if it has no calls. That can happen because the calls
are recorded against the main thread's initial comm.
Add a table column to make it easy for the exported-sql-viewer.py script to
select only comms with calls.
Committer testing:
$ rm -f simple-retpoline.db
$ sudo ~acme/bin/perf script -i simple-retpoline.perf.data --itrace=be -s ~/libexec/perf-core/scripts/python/export-to-sqlite.py simple-retpoline.db branches calls
2019-07-10 12:25:33.200529 Creating database ...
2019-07-10 12:25:33.211548 Writing records...
2019-07-10 12:25:33.549630 Adding indexes
2019-07-10 12:25:33.560715 Dropping unused tables
2019-07-10 12:25:33.580201 Done
$ sha256sum tools/perf/scripts/python/export-to-sqlite.py ~/libexec/perf-core/scripts/python/export-to-sqlite.py
2922b642c392004dffa1d8789296478c85904623f5895bcb9b6cbf33e3ca999f tools/perf/scripts/python/export-to-sqlite.py
2922b642c392004dffa1d8789296478c85904623f5895bcb9b6cbf33e3ca999f /home/acme/libexec/perf-core/scripts/python/export-to-sqlite.py
$
$ sqlite3 simple-retpoline.db
SQLite version 3.26.0 2018-12-01 12:34:55
Enter ".help" for usage hints.
sqlite> .schema comms
CREATE TABLE comms (id integer NOT NULL PRIMARY KEY,comm varchar(16),c_thread_id bigint,c_time bigint,exec_flag boolean, has_calls boolean);
sqlite> select id,has_calls from comms;
0|1
1|1
sqlite> select distinct comm_id from calls;
0
1
sqlite>
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
PostgreSQL can error if power_events_view is not dropped before its
dependent tables e.g.
Exception: Query failed: ERROR: cannot drop table mwait because other
objects depend on it
DETAIL: view power_events_view depends on table mwait
Signed-off-by: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Fixes: aba44287a2 ("perf scripts python: export-to-postgresql.py: Export Intel PT power and ptwrite events")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
The format of synthesized events is determined by the attribute config.
For the formats for Intel PT power and ptwrite events, create tables and
populate them when the synth_data handler is called. If the tables
remain empty, drop them at the end.
The tables and views, including a combined power_events_view, will
display automatically from the tables menu of the exported
exported-sql-viewer.py script.
Note, currently only Atoms since Gemini Lake have support for ptwrite
and mwait, pwre, exstop and pwrx, but all Intel PT implementations
support cbr.
Signed-off-by: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
The compiler might optimize a call/ret combination by making it a jmp.
However the thread-stack does not presently cater for that, so that such
control flow is not visible in the call graph. Make it visible by
recording on the stack a branch to the start of a different symbol.
Note, that means when a ret pops the stack, all jmps must be popped off
first.
Example:
$ cat jmp-to-fn.c
__attribute__((noinline)) int bar(void)
{
return -1;
}
__attribute__((noinline)) int foo(void)
{
return bar() + 1;
}
int main()
{
return foo();
}
$ gcc -ggdb3 -Wall -Wextra -O2 -o jmp-to-fn jmp-to-fn.c
$ objdump -d jmp-to-fn
<SNIP>
0000000000001040 <main>:
1040: 31 c0 xor %eax,%eax
1042: e9 09 01 00 00 jmpq 1150 <foo>
<SNIP>
0000000000001140 <bar>:
1140: b8 ff ff ff ff mov $0xffffffff,%eax
1145: c3 retq
<SNIP>
0000000000001150 <foo>:
1150: 31 c0 xor %eax,%eax
1152: e8 e9 ff ff ff callq 1140 <bar>
1157: 83 c0 01 add $0x1,%eax
115a: c3 retq
<SNIP>
$ perf record -o jmp-to-fn.perf.data -e intel_pt/cyc/u ./jmp-to-fn
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0,017 MB jmp-to-fn.perf.data ]
$ perf script -i jmp-to-fn.perf.data --itrace=be -s ~/libexec/perf-core/scripts/python/export-to-sqlite.py jmp-to-fn.db branches calls
2019-01-08 13:24:58.783069 Creating database...
2019-01-08 13:24:58.794650 Writing records...
2019-01-08 13:24:59.008050 Adding indexes
2019-01-08 13:24:59.015802 Done
$ ~/libexec/perf-core/scripts/python/exported-sql-viewer.py jmp-to-fn.db
Before:
main
-> bar
After:
main
-> foo
-> bar
Committer testing:
Install the python2-pyside package, then select these menu options
on the GUI:
"Reports"
"Context sensitive callgraphs"
Then go on expanding the symbols, to get, full picture when doing this
on a fedora:29 with gcc version 8.2.1 20181215 (Red Hat 8.2.1-6) (GCC):
jmp-to-fn
PID:TID
_start (ld-2.28.so)
__libc_start_main
main
foo
bar
To verify that indeed, this fixes the problem.
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
The export does not work if only branches are exported because of a
missing column in the samples table. Fix by adding the missing
call_path_id.
Fixes: 3521f3bc9d ("perf script: Update export-to-postgresql to support callchain export")
Signed-off-by: Adrian Hunter <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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 <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
The current instructions for setting up an Ubuntu system for using the
export-to-postgresql.py script are incorrect.
The instructions in the script have been updated to work on newer
versions of ubuntu.
-Add missing dependencies to apt-get command:
python-pyside.qtsql, libqt4-sql-psql
-Add '-s' option to createuser command to force the user to be a
superuser since the command doesn't prompt as indicated in the
current instructions.
Tested on: Ubuntu 14.04, Ubuntu 16.04(beta)
Signed-off-by: Chris Phlipot <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Add a script to produce a call-graph from data exported to a postgresql
database and derived from a processor trace event like intel_pt or intel_bts.
Refer to comments in the scripts call-graph-from-postgresql.py and
export-to-postgresql.py for more details on how to set up the environment,
install the required packages, etc.
Committer note:
From the scripts, for convenience while reading 'git log':
An example of using this script with Intel PT:
$ perf record -e intel_pt//u ls
$ perf script -s ~/libexec/perf-core/scripts/python/export-to-postgresql.py pt_example branches calls
2015-05-29 12:49:23.464364 Creating database...
2015-05-29 12:49:26.281717 Writing to intermediate files...
2015-05-29 12:49:27.190383 Copying to database...
2015-05-29 12:49:28.140451 Removing intermediate files...
2015-05-29 12:49:28.147451 Adding primary keys
2015-05-29 12:49:28.655683 Adding foreign keys
2015-05-29 12:49:29.365350 Done
$ python tools/perf/scripts/python/call-graph-from-postgresql.py pt_example
# The result is a GUI window with a tree representing a context-sensitive
# call-graph. Expanding a couple of levels of the tree and adjusting column
# widths to suit will display something like:
Call Graph: pt_example
Call Path |Object |Count|Time(ns)|Time(%)|Branch Count|Branch Count(%)
v- ls
v- 2638:2638
v- _start ld-2.19.so 1 10074071 100.0 211135 100.0
|- unknown unknown 1 13198 0.1 1 0.0
>- _dl_start ld-2.19.so 1 1400980 13.9 19637 9.3
>- _d_linit_internal ld-2.19.so 1 448152 4.4 11094 5.3
v-__libc_start_main@plt ls 1 8211741 81.5 180397 85.4
>- _dl_fixup ld-2.19.so 1 7607 0.1 108 0.1
>- __cxa_atexit libc-2.19.so 1 11737 0.1 10 0.0
>- __libc_csu_init ls 1 10354 0.1 10 0.0
|- _setjmp libc-2.19.so 1 0 0.0 4 0.0
v- main ls 1 8182043 99.6 180254 99.9
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Added 'python-pyside qt-postgresql' to the yum cmdline installing required packages ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Adrian Hunter