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
524 seconds. Since the clock access is designed for use in tracing,
570 that are written into /sys/kernel/tracing/events/ftrace/print/trigger
614 A list of events that can be enabled in tracing.
627 Usual timestamp modes for tracing:
805 This tracer can be configured when tracing likely/unlikely
813 tracers from tracing simply echo "nop" into
823 available via the tracing/error_log file. For the commands that
824 support it, reading the tracing/error_log file after an error will
826 information is available. The tracing/error_log file is a circular
833 # echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
836 # cat /sys/kernel/debug/tracing/error_log
846 # echo > /sys/kernel/debug/tracing/error_log
940 This shows that the current tracer is "irqsoff" tracing the time
1172 When the file is closed, tracing will be enabled again.
1186 impact of tracing. See "saved_cmdlines".
1202 When the free_buffer is closed, tracing will
1234 The latency tracers will enable function tracing
1251 use function graph tracing instead of function tracing.
1258 Enable branch tracing with the tracer. This enables branch
1496 enabling function tracing, we incur an added overhead. This
1774 function tracing, we do not know if interrupts were enabled
1882 One common case that people are interested in tracing is the
1884 Now for non Real-Time tasks, this can be arbitrary. But tracing
1887 Without function tracing::
1919 to avoid tracing the normal circumstances. Here we see that
1946 tracing non-RT tasks that are unpredictable will overwrite the
1990 is before the actual "switch", we stop the tracing when the recorded task
2117 This isn't that big of a trace, even with function tracing enabled,
2124 Latency tracing and events
2126 As function tracing can induce a much larger latency, but without
2307 the tracing could have overwritten the data that you wanted to
2309 tracing directly from a program. This allows you to stop the
2310 tracing at the point that you hit the part that you are
2311 interested in. To disable the tracing directly from a C program,
2327 Single thread tracing
2408 strcat(tracefs, "/tracing/");
2528 function calls while cpu tracing switch.
2691 following "dynamic ftrace" section such as tracing only specific
2698 virtually no overhead when function tracing is disabled. The way
2732 When tracing is enabled, the process of modifying the function
2757 tracing of specified functions. They are:
2949 We can see that there's no more lock or preempt tracing.
3049 function tracer. By default it is enabled (when function tracing is
3050 enabled in the kernel). If it is disabled, all function tracing is
3052 also for any other uses (perf, kprobes, stack tracing, profiling, etc). It
3094 Mod command supports module globbing. Disable tracing for all
3099 Disable tracing for all modules, but still trace kernel::
3112 These commands turn tracing on and off when the specified
3114 tracing system is turned on and off. If unspecified, there is
3115 no limit. For example, to disable tracing when a schedule bug
3120 To always disable tracing when __schedule_bug is hit::
3153 function tracing callbacks are very sensitive, when these commands
3195 the effect on the tracing is different. Every read from
3234 the trace file for reading, it will actually disable tracing and
3305 in time without stopping tracing. Ftrace swaps the current
3306 buffer with a spare buffer, and tracing continues in the new
3309 The following tracefs files in "tracing" are related to this
3319 System"). Both reads snapshot and tracing are executable
3385 In the tracefs tracing directory, there is a directory called "instances".
3398 As you can see, the new directory looks similar to the tracing directory
3404 same name in the tracing directory except the buffer that is used
3496 the function tracing. The foo instance displays wakeups and task
3524 CONFIG_STACK_TRACER enables the ftrace stack tracing functionality.