linux/kernel/trace
Steven Rostedt 5072c59fd4 ftrace: add filter select functions to trace
This patch adds two files to the debugfs system:

 /debugfs/tracing/available_filter_functions

and

 /debugfs/tracing/set_ftrace_filter

The available_filter_functions lists all functions that has been
recorded by the ftraced that has called the ftrace_record_ip function.
This is to allow users to see what functions have been converted
to nops and can be enabled for tracing.

To enable functions, simply echo the names (whitespace delimited)
into set_ftrace_filter. Simple wildcards are also allowed.

echo 'scheduler' > /debugfs/tracing/set_ftrace_filter

Will have only the scheduler be activated when tracing is enabled.

echo 'sched_*' > /debugfs/tracing/set_ftrace_filter

Will have only the functions starting with 'sched_' be activated.

echo '*lock' > /debugfs/tracing/set_ftrace_filter

Will have only functions ending with 'lock' be activated.

echo '*lock*' > /debugfs/tracing/set_ftrace_filter

Will have only functions with 'lock' in its name be activated.

Note: 'sched*lock' will not work. The only wildcards that are
allowed is an asterisk and the beginning and or end of the string
passed in.

Multiple names can be passed in with whitespace delimited:

echo 'scheduler *lock *acpi*' > /debugfs/tracing/set_ftrace_filter

is also the same as:

echo 'scheduler' > /debugfs/tracing/set_ftrace_filter
echo '*lock' >> /debugfs/tracing/set_ftrace_filter
echo '*acpi*' >> /debugfs/tracing/set_ftrace_filter

Appending does just that. It appends to the list.

To disable all filters simply echo an empty line in:

echo > /debugfs/tracing/set_ftrace_filter

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 20:38:41 +02:00
..
ftrace.c ftrace: add filter select functions to trace 2008-05-23 20:38:41 +02:00
Kconfig ftrace: dynamic enabling/disabling of function calls 2008-05-23 20:33:09 +02:00
Makefile ftrace: trace preempt off critical timings 2008-05-23 20:32:54 +02:00
trace.c ftrace: latency tracer infrastructure 2008-05-23 20:32:06 +02:00
trace.h ftrace: latency tracer infrastructure 2008-05-23 20:32:06 +02:00
trace_functions.c ftrace: function tracer 2008-05-23 20:32:13 +02:00
trace_irqsoff.c ftrace: trace preempt off critical timings 2008-05-23 20:32:54 +02:00
trace_sched_switch.c ftrace: add tracing of context switches 2008-05-23 20:32:27 +02:00
trace_sched_wakeup.c ftrace: tracer for scheduler wakeup latency 2008-05-23 20:32:36 +02:00