trace_event=[event-list]
-The format of this boot option is the same as described in section 2.1.
+event-list is a comma separated list of events. See section 2.1 for event
+format.
3. Defining an event-enabled tracepoint
=======================================
For convenience, filters for every event in a subsystem can be set or
cleared as a group by writing a filter expression into the filter file
-at the root of the subsytem. Note however, that if a filter for any
+at the root of the subsystem. Note however, that if a filter for any
event within the subsystem lacks a field specified in the subsystem
filter, or if the filter can't be applied for any other reason, the
filter for that event will retain its previous setting. This can
Here are a few subsystem filter examples that also illustrate the
above points:
-Clear the filters on all events in the sched subsytem:
+Clear the filters on all events in the sched subsystem:
# cd /sys/kernel/debug/tracing/events/sched
# echo 0 > filter
none
Set a filter using only common fields for all events in the sched
-subsytem (all events end up with the same filter):
+subsystem (all events end up with the same filter):
# cd /sys/kernel/debug/tracing/events/sched
# echo common_pid == 0 > filter
common_pid == 0
Attempt to set a filter using a non-common field for all events in the
-sched subsytem (all events but those that have a prev_pid field retain
+sched subsystem (all events but those that have a prev_pid field retain
their old filters):
# cd /sys/kernel/debug/tracing/events/sched