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.
1168 impact of tracing. See "saved_cmdlines".
1184 When the free_buffer is closed, tracing will
1216 The latency tracers will enable function tracing
1233 use function graph tracing instead of function tracing.
1240 Enable branch tracing with the tracer. This enables branch
1478 enabling function tracing, we incur an added overhead. This
1756 function tracing, we do not know if interrupts were enabled
1864 One common case that people are interested in tracing is the
1866 Now for non Real-Time tasks, this can be arbitrary. But tracing
1869 Without function tracing::
1901 to avoid tracing the normal circumstances. Here we see that
1928 tracing non-RT tasks that are unpredictable will overwrite the
1972 is before the actual "switch", we stop the tracing when the recorded task
2099 This isn't that big of a trace, even with function tracing enabled,
2106 Latency tracing and events
2108 As function tracing can induce a much larger latency, but without
2289 the tracing could have overwritten the data that you wanted to
2291 tracing directly from a program. This allows you to stop the
2292 tracing at the point that you hit the part that you are
2293 interested in. To disable the tracing directly from a C program,
2309 Single thread tracing
2390 strcat(tracefs, "/tracing/");
2439 echo nop > $tracefs/tracing/current_tracer
2440 echo 0 > $tracefs/tracing/tracing_on
2441 echo $$ > $tracefs/tracing/set_ftrace_pid
2442 echo function > $tracefs/tracing/current_tracer
2443 echo 1 > $tracefs/tracing/tracing_on
2511 function calls while cpu tracing switch.
2674 following "dynamic ftrace" section such as tracing only specific
2681 virtually no overhead when function tracing is disabled. The way
2715 When tracing is enabled, the process of modifying the function
2740 tracing of specified functions. They are:
2932 We can see that there's no more lock or preempt tracing.
3032 function tracer. By default it is enabled (when function tracing is
3033 enabled in the kernel). If it is disabled, all function tracing is
3035 also for any other uses (perf, kprobes, stack tracing, profiling, etc). It
3077 Mod command supports module globbing. Disable tracing for all
3082 Disable tracing for all modules, but still trace kernel::
3095 These commands turn tracing on and off when the specified
3097 tracing system is turned on and off. If unspecified, there is
3098 no limit. For example, to disable tracing when a schedule bug
3103 To always disable tracing when __schedule_bug is hit::
3136 function tracing callbacks are very sensitive, when these commands
3178 the effect on the tracing is different. Every read from
3217 the trace file for reading, it will actually disable tracing and
3288 in time without stopping tracing. Ftrace swaps the current
3289 buffer with a spare buffer, and tracing continues in the new
3292 The following tracefs files in "tracing" are related to this
3302 System"). Both reads snapshot and tracing are executable
3368 In the tracefs tracing directory is a directory called "instances".
3381 As you can see, the new directory looks similar to the tracing directory
3387 same name in the tracing directory except the buffer that is used
3479 the function tracing. The foo instance displays wakeups and task
3507 CONFIG_STACK_TRACER enables the ftrace stack tracing functionality.