Lines Matching refs:tracing
27 is really a framework of several assorted tracing utilities.
28 There's latency tracing to examine what occurs between interrupts
32 One of the most common uses of ftrace is the event tracing.
53 option will do) the directory /sys/kernel/tracing will be created. To mount
56 tracefs /sys/kernel/tracing tracefs defaults 0 0
60 mount -t tracefs nodev /sys/kernel/tracing
65 ln -s /sys/kernel/tracing /tracing
69 Before 4.1, all ftrace tracing control files were within the debugfs
70 file system, which is typically located at /sys/kernel/debug/tracing.
74 /sys/kernel/debug/tracing
83 (cd /sys/kernel/tracing) and will only concentrate on the files within that
85 "/sys/kernel/tracing" path name.
112 writing to the ring buffer, the tracing overhead may
117 set this file to "0". User space can re-enable tracing by
121 set this file to zero and stop tracing. Which can also
127 readable format (described below). Note, tracing is temporarily
129 are closed, tracing is re-enabled.
134 file is meant to be streamed with live tracing.
145 temporarily disable tracing.
204 If a process is performing tracing, and the ring buffer should be
208 Having a process that is tracing also open this file, when the process
212 It may also stop tracing if disable_on_free option is set.
224 function profiler (mcount). This lets tracing be configured
239 and requires a check of all functions registered to tracing, instead
284 tracing when the function is hit until it exits the function.
285 This makes it possible to ignore tracing functions that are called
344 A directory that holds different tracing stats.
427 Usual clocks for tracing::
480 tracing in the suspend path, some side effects are possible
524 that are written into /sys/kernel/tracing/events/ftrace/print/trigger
568 A list of events that can be enabled in tracing.
581 Usual timestamp modes for tracing:
759 This tracer can be configured when tracing likely/unlikely
767 tracers from tracing simply echo "nop" into
777 available via the tracing/error_log file. For the commands that
778 support it, reading the tracing/error_log file after an error will
780 information is available. The tracing/error_log file is a circular
787 # echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
790 # cat /sys/kernel/debug/tracing/error_log
800 # echo > /sys/kernel/debug/tracing/error_log
894 This shows that the current tracer is "irqsoff" tracing the time
1128 impact of tracing. See "saved_cmdlines".
1144 When the free_buffer is closed, tracing will
1174 The latency tracers will enable function tracing
1189 use function graph tracing instead of function tracing.
1196 Enable branch tracing with the tracer. This enables branch
1434 enabling function tracing, we incur an added overhead. This
1712 function tracing, we do not know if interrupts were enabled
1820 One common case that people are interested in tracing is the
1822 Now for non Real-Time tasks, this can be arbitrary. But tracing
1825 Without function tracing::
1857 to avoid tracing the normal circumstances. Here we see that
1884 tracing non-RT tasks that are unpredictable will overwrite the
1928 is before the actual "switch", we stop the tracing when the recorded task
2055 This isn't that big of a trace, even with function tracing enabled,
2062 Latency tracing and events
2064 As function tracing can induce a much larger latency, but without
2233 the tracing could have overwritten the data that you wanted to
2235 tracing directly from a program. This allows you to stop the
2236 tracing at the point that you hit the part that you are
2237 interested in. To disable the tracing directly from a C program,
2253 Single thread tracing
2334 strcat(tracefs, "/tracing/");
2383 echo nop > $tracefs/tracing/current_tracer
2384 echo 0 > $tracefs/tracing/tracing_on
2385 echo $$ > $tracefs/tracing/set_ftrace_pid
2386 echo function > $tracefs/tracing/current_tracer
2387 echo 1 > $tracefs/tracing/tracing_on
2455 function calls while cpu tracing switch.
2618 following "dynamic ftrace" section such as tracing only specific
2625 virtually no overhead when function tracing is disabled. The way
2659 When tracing is enabled, the process of modifying the function
2684 tracing of specified functions. They are:
2876 We can see that there's no more lock or preempt tracing.
2976 function tracer. By default it is enabled (when function tracing is
2977 enabled in the kernel). If it is disabled, all function tracing is
2979 also for any other uses (perf, kprobes, stack tracing, profiling, etc).
3019 Mod command supports module globbing. Disable tracing for all
3024 Disable tracing for all modules, but still trace kernel::
3037 These commands turn tracing on and off when the specified
3039 tracing system is turned on and off. If unspecified, there is
3040 no limit. For example, to disable tracing when a schedule bug
3045 To always disable tracing when __schedule_bug is hit::
3078 function tracing callbacks are very sensitive, when these commands
3120 the effect on the tracing is different. Every read from
3159 the trace file for reading, it will actually disable tracing and
3230 in time without stopping tracing. Ftrace swaps the current
3231 buffer with a spare buffer, and tracing continues in the new
3234 The following tracefs files in "tracing" are related to this
3244 System"). Both reads snapshot and tracing are executable
3310 In the tracefs tracing directory is a directory called "instances".
3323 As you can see, the new directory looks similar to the tracing directory
3329 same name in the tracing directory except the buffer that is used
3421 the function tracing. The foo instance displays wakeups and task
3449 CONFIG_STACK_TRACER enables the ftrace stack tracing functionality.