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.
113 writing to the ring buffer, the tracing overhead may
118 set this file to "0". User space can re-enable tracing by
122 set this file to zero and stop tracing. Which can also
130 Note, this file is not a consumer. If tracing is off
132 the same output each time it is read. When tracing is on,
139 file is meant to be streamed with live tracing.
208 If a process is performing tracing, and the ring buffer should be
212 Having a process that is tracing also open this file, when the process
216 It may also stop tracing if disable_on_free option is set.
228 function profiler (mcount). This lets tracing be configured
243 and requires a check of all functions registered to tracing, instead
315 tracing when the function is hit until it exits the function.
316 This makes it possible to ignore tracing functions that are called
391 grep ' M ' /sys/kernel/tracing/touched_functions
406 A directory that holds different tracing stats.
489 Usual clocks for tracing::
542 tracing in the suspend path, some side effects are possible
555 seconds. Since the clock access is designed for use in tracing,
601 that are written into /sys/kernel/tracing/events/ftrace/print/trigger
645 A list of events that can be enabled in tracing.
658 Usual timestamp modes for tracing:
836 This tracer can be configured when tracing likely/unlikely
844 tracers from tracing simply echo "nop" into
854 available via the tracing/error_log file. For the commands that
855 support it, reading the tracing/error_log file after an error will
857 information is available. The tracing/error_log file is a circular
864 # echo xxx > /sys/kernel/tracing/events/sched/sched_wakeup/trigger
867 # cat /sys/kernel/tracing/error_log
877 # echo > /sys/kernel/tracing/error_log
971 This shows that the current tracer is "irqsoff" tracing the time
1209 When the file is closed, tracing will be enabled again.
1223 impact of tracing. See "saved_cmdlines".
1239 When the free_buffer is closed, tracing will
1271 The latency tracers will enable function tracing
1288 use function graph tracing instead of function tracing.
1295 Enable branch tracing with the tracer. This enables branch
1546 enabling function tracing, we incur an added overhead. This
1824 function tracing, we do not know if interrupts were enabled
1932 One common case that people are interested in tracing is the
1934 Now for non Real-Time tasks, this can be arbitrary. But tracing
1937 Without function tracing::
1969 to avoid tracing the normal circumstances. Here we see that
1996 tracing non-RT tasks that are unpredictable will overwrite the
2040 is before the actual "switch", we stop the tracing when the recorded task
2167 This isn't that big of a trace, even with function tracing enabled,
2174 Latency tracing and events
2176 As function tracing can induce a much larger latency, but without
2357 the tracing could have overwritten the data that you wanted to
2359 tracing directly from a program. This allows you to stop the
2360 tracing at the point that you hit the part that you are
2361 interested in. To disable the tracing directly from a C program,
2377 Single thread tracing
2458 strcat(tracefs, "/tracing/");
2578 function calls while cpu tracing switch.
2854 following "dynamic ftrace" section such as tracing only specific
2861 virtually no overhead when function tracing is disabled. The way
2895 When tracing is enabled, the process of modifying the function
2920 tracing of specified functions. They are:
3112 We can see that there's no more lock or preempt tracing.
3212 function tracer. By default it is enabled (when function tracing is
3213 enabled in the kernel). If it is disabled, all function tracing is
3215 also for any other uses (perf, kprobes, stack tracing, profiling, etc). It
3257 Mod command supports module globbing. Disable tracing for all
3262 Disable tracing for all modules, but still trace kernel::
3275 These commands turn tracing on and off when the specified
3277 tracing system is turned on and off. If unspecified, there is
3278 no limit. For example, to disable tracing when a schedule bug
3283 To always disable tracing when __schedule_bug is hit::
3316 function tracing callbacks are very sensitive, when these commands
3358 the effect on the tracing is different. Every read from
3397 the trace file for reading, it will actually disable tracing and
3468 in time without stopping tracing. Ftrace swaps the current
3469 buffer with a spare buffer, and tracing continues in the new
3472 The following tracefs files in "tracing" are related to this
3482 System"). Both reads snapshot and tracing are executable
3548 In the tracefs tracing directory, there is a directory called "instances".
3561 As you can see, the new directory looks similar to the tracing directory
3567 same name in the tracing directory except the buffer that is used
3659 the function tracing. The foo instance displays wakeups and task
3687 CONFIG_STACK_TRACER enables the ftrace stack tracing functionality.