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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-03-13 10:17:50 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-03-15 00:36:05 -0400 |
| commit | dd42cd3ea96d687f15525c4f14fa582702db223f (patch) | |
| tree | 135eb362cc41f54392d10af19fc4e10ef7060081 /mm/huge_memory.c | |
| parent | c142be8ebe0b7bf73c8a0063925623f3e4b980c0 (diff) | |
| download | talos-op-linux-dd42cd3ea96d687f15525c4f14fa582702db223f.tar.gz talos-op-linux-dd42cd3ea96d687f15525c4f14fa582702db223f.zip | |
tracing: Add function probe to trigger stack traces
Add a function probe that will cause a stack trace to be traced in
the ring buffer when the given function(s) are called.
format is:
<function>:stacktrace[:<count>]
echo 'schedule:stacktrace' > /debug/tracing/set_ftrace_filter
cat /debug/tracing/trace_pipe
kworker/2:0-4329 [002] ...2 2933.558007: <stack trace>
=> kthread
=> ret_from_fork
<idle>-0 [000] .N.2 2933.558019: <stack trace>
=> rest_init
=> start_kernel
=> x86_64_start_reservations
=> x86_64_start_kernel
kworker/2:0-4329 [002] ...2 2933.558109: <stack trace>
=> kthread
=> ret_from_fork
[...]
This can be set to only trace a specific amount of times:
echo 'schedule:stacktrace:3' > /debug/tracing/set_ftrace_filter
cat /debug/tracing/trace_pipe
<...>-58 [003] ...2 841.801694: <stack trace>
=> kthread
=> ret_from_fork
<idle>-0 [001] .N.2 841.801697: <stack trace>
=> start_secondary
<...>-2059 [001] ...2 841.801736: <stack trace>
=> wait_for_common
=> wait_for_completion
=> flush_work
=> tty_flush_to_ldisc
=> input_available_p
=> n_tty_poll
=> tty_poll
=> do_select
=> core_sys_select
=> sys_select
=> system_call_fastpath
To remove these:
echo '!schedule:stacktrace' > /debug/tracing/set_ftrace_filter
echo '!schedule:stacktrace:0' > /debug/tracing/set_ftrace_filter
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'mm/huge_memory.c')
0 files changed, 0 insertions, 0 deletions
