diff options
| author | Török Edwin <edwintorok@gmail.com> | 2008-11-22 13:28:47 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-23 09:25:15 +0100 |
| commit | 02b67518e2b1c490787dac7f35e1204e74fe21ba (patch) | |
| tree | a3d92846e1a09a829f300ab15726ee9c288cb49e /Documentation | |
| parent | a0a70c735ef714fe1b6777b571630c3d50c7b008 (diff) | |
tracing: add support for userspace stacktraces in tracing/iter_ctrl
Impact: add new (default-off) tracing visualization feature
Usage example:
mount -t debugfs nodev /sys/kernel/debug
cd /sys/kernel/debug/tracing
echo userstacktrace >iter_ctrl
echo sched_switch >current_tracer
echo 1 >tracing_enabled
.... run application ...
echo 0 >tracing_enabled
Then read one of 'trace','latency_trace','trace_pipe'.
To get the best output you can compile your userspace programs with
frame pointers (at least glibc + the app you are tracing).
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ftrace.txt | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/Documentation/ftrace.txt b/Documentation/ftrace.txt index 753f4de4b17..79a80f79c06 100644 --- a/Documentation/ftrace.txt +++ b/Documentation/ftrace.txt @@ -324,7 +324,7 @@ output. To see what is available, simply cat the file: cat /debug/tracing/trace_options print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \ - noblock nostacktrace nosched-tree + noblock nostacktrace nosched-tree nouserstacktrace To disable one of the options, echo in the option prepended with "no". @@ -378,6 +378,9 @@ Here are the available options: When a trace is recorded, so is the stack of functions. This allows for back traces of trace sites. + userstacktrace - This option changes the trace. + It records a stacktrace of the current userspace thread. + sched-tree - TBD (any users??) |