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
375 A directory that holds different tracing stats.
458 Usual clocks for tracing::
511 tracing in the suspend path, some side effects are possible
558 that are written into /sys/kernel/tracing/events/ftrace/print/trigger
602 A list of events that can be enabled in tracing.
615 Usual timestamp modes for tracing:
793 This tracer can be configured when tracing likely/unlikely
801 tracers from tracing simply echo "nop" into
811 available via the tracing/error_log file. For the commands that
812 support it, reading the tracing/error_log file after an error will
814 information is available. The tracing/error_log file is a circular
821 # echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
824 # cat /sys/kernel/debug/tracing/error_log
834 # echo > /sys/kernel/debug/tracing/error_log
928 This shows that the current tracer is "irqsoff" tracing the time
1160 When the file is closed, tracing will be enabled again.
1174 impact of tracing. See "saved_cmdlines".
1190 When the free_buffer is closed, tracing will
1222 The latency tracers will enable function tracing
1239 use function graph tracing instead of function tracing.
1246 Enable branch tracing with the tracer. This enables branch
1484 enabling function tracing, we incur an added overhead. This
1762 function tracing, we do not know if interrupts were enabled
1870 One common case that people are interested in tracing is the
1872 Now for non Real-Time tasks, this can be arbitrary. But tracing
1875 Without function tracing::
1907 to avoid tracing the normal circumstances. Here we see that
1934 tracing non-RT tasks that are unpredictable will overwrite the
1978 is before the actual "switch", we stop the tracing when the recorded task
2105 This isn't that big of a trace, even with function tracing enabled,
2112 Latency tracing and events
2114 As function tracing can induce a much larger latency, but without
2295 the tracing could have overwritten the data that you wanted to
2297 tracing directly from a program. This allows you to stop the
2298 tracing at the point that you hit the part that you are
2299 interested in. To disable the tracing directly from a C program,
2315 Single thread tracing
2396 strcat(tracefs, "/tracing/");
2445 echo nop > $tracefs/tracing/current_tracer
2446 echo 0 > $tracefs/tracing/tracing_on
2447 echo $$ > $tracefs/tracing/set_ftrace_pid
2448 echo function > $tracefs/tracing/current_tracer
2449 echo 1 > $tracefs/tracing/tracing_on
2517 function calls while cpu tracing switch.
2680 following "dynamic ftrace" section such as tracing only specific
2687 virtually no overhead when function tracing is disabled. The way
2721 When tracing is enabled, the process of modifying the function
2746 tracing of specified functions. They are:
2938 We can see that there's no more lock or preempt tracing.
3038 function tracer. By default it is enabled (when function tracing is
3039 enabled in the kernel). If it is disabled, all function tracing is
3041 also for any other uses (perf, kprobes, stack tracing, profiling, etc). It
3083 Mod command supports module globbing. Disable tracing for all
3088 Disable tracing for all modules, but still trace kernel::
3101 These commands turn tracing on and off when the specified
3103 tracing system is turned on and off. If unspecified, there is
3104 no limit. For example, to disable tracing when a schedule bug
3109 To always disable tracing when __schedule_bug is hit::
3142 function tracing callbacks are very sensitive, when these commands
3184 the effect on the tracing is different. Every read from
3223 the trace file for reading, it will actually disable tracing and
3294 in time without stopping tracing. Ftrace swaps the current
3295 buffer with a spare buffer, and tracing continues in the new
3298 The following tracefs files in "tracing" are related to this
3308 System"). Both reads snapshot and tracing are executable
3374 In the tracefs tracing directory is a directory called "instances".
3387 As you can see, the new directory looks similar to the tracing directory
3393 same name in the tracing directory except the buffer that is used
3485 the function tracing. The foo instance displays wakeups and task
3513 CONFIG_STACK_TRACER enables the ftrace stack tracing functionality.