diff options
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/ftrace.rst | 3 | ||||
| -rw-r--r-- | Documentation/trace/histogram.rst | 6 |
2 files changed, 6 insertions, 3 deletions
diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 7ea16a0ceffc..f82434f2795e 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -2987,6 +2987,9 @@ The following commands are supported: command, it only prints out the contents of the ring buffer for the CPU that executed the function that triggered the dump. +- stacktrace: + When the function is hit, a stack trace is recorded. + trace_pipe ---------- diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst index 5ac724baea7d..7dda76503127 100644 --- a/Documentation/trace/histogram.rst +++ b/Documentation/trace/histogram.rst @@ -1765,7 +1765,7 @@ For example, here's how a latency can be calculated:: # echo 'hist:keys=pid,prio:ts0=common_timestamp ...' >> event1/trigger # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp-$ts0 ...' >> event2/trigger -In the first line above, the event's timetamp is saved into the +In the first line above, the event's timestamp is saved into the variable ts0. In the next line, ts0 is subtracted from the second event's timestamp to produce the latency, which is then assigned into yet another variable, 'wakeup_lat'. The hist trigger below in turn @@ -1811,7 +1811,7 @@ the command that defined it with a '!':: /sys/kernel/debug/tracing/synthetic_events At this point, there isn't yet an actual 'wakeup_latency' event -instantiated in the event subsytem - for this to happen, a 'hist +instantiated in the event subsystem - for this to happen, a 'hist trigger action' needs to be instantiated and bound to actual fields and variables defined on other events (see Section 2.2.3 below on how that is done using hist trigger 'onmatch' action). Once that is @@ -1837,7 +1837,7 @@ output can be displayed by reading the event's 'hist' file. A hist trigger 'action' is a function that's executed whenever a histogram entry is added or updated. -The default 'action' if no special function is explicity specified is +The default 'action' if no special function is explicitly specified is as it always has been, to simply update the set of values associated with an entry. Some applications, however, may want to perform additional actions at that point, such as generate another event, or |
