From 2ab2a0924b9980551ebe1c47d2a402a94efc1835 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Thu, 26 Mar 2020 13:22:44 -0400 Subject: tracing: Add documentation on set_ftrace_notrace_pid and set_event_notrace_pid Update the tracing documentation to reflect the new files in the tracing directory. Signed-off-by: Steven Rostedt (VMware) --- Documentation/trace/ftrace.rst | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'Documentation/trace') diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 00621731bf27..3b5614b1d1a5 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -263,6 +263,20 @@ of ftrace. Here is a list of some of the key files: traced by the function tracer as well. This option will also cause PIDs of tasks that exit to be removed from the file. + set_ftrace_notrace_pid: + + Have the function tracer ignore threads whose PID are listed in + this file. + + If the "function-fork" option is set, then when a task whose + PID is listed in this file forks, the child's PID will + automatically be added to this file, and the child will not be + traced by the function tracer as well. This option will also + cause PIDs of tasks that exit to be removed from the file. + + If a PID is in both this file and "set_ftrace_pid", then this + file takes precedence, and the thread will not be traced. + set_event_pid: Have the events only trace a task with a PID listed in this file. @@ -274,6 +288,19 @@ of ftrace. Here is a list of some of the key files: cause the PIDs of tasks to be removed from this file when the task exits. + set_event_notrace_pid: + + Have the events not trace a task with a PID listed in this file. + Note, sched_switch and sched_wakeup will trace threads not listed + in this file, even if a thread's PID is in the file if the + sched_switch or sched_wakeup events also trace a thread that should + be traced. + + To have the PIDs of children of tasks with their PID in this file + added on fork, enable the "event-fork" option. That option will also + cause the PIDs of tasks to be removed from this file when the task + exits. + set_graph_function: Functions listed in this file will cause the function graph @@ -1183,6 +1210,8 @@ Here are the available options: tasks fork. Also, when tasks with PIDs in set_event_pid exit, their PIDs will be removed from the file. + This affects PIDs listed in set_event_notrace_pid as well. + function-trace The latency tracers will enable function tracing if this option is enabled (default it is). When @@ -1197,6 +1226,8 @@ Here are the available options: set_ftrace_pid exit, their PIDs will be removed from the file. + This affects PIDs in set_ftrace_notrace_pid as well. + display-graph When set, the latency tracers (irqsoff, wakeup, etc) will use function graph tracing instead of function tracing. -- cgit v1.2.3