19 Dec, 2008
1 commit
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Impact: cleanup
This patch factors out common code from multiple tracers into a
tracing_reset_online_cpus() function and converts the tracers to use it.Signed-off-by: Pekka Enberg
Signed-off-by: Ingo Molnar
16 Nov, 2008
1 commit
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Impact: extend the ->init() method with the ability to fail
This bring a way to know if the initialization of a tracer successed.
A tracer must return 0 on success and a traditional error (ie:
-ENOMEM) if it fails.If a tracer fails to init, it is free to print a detailed warn. The
tracing api will not and switch to a new tracer will just return the
error from the init callback.Note: this will be used for the return tracer.
Signed-off-by: Frederic Weisbecker
Signed-off-by: Ingo Molnar
08 Nov, 2008
2 commits
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Impact: remove obsolete variable in trace_array structure
With the new start / stop method of ftrace, the ctrl variable
in the trace_array structure is now obsolete. Remove it.Signed-off-by: Steven Rostedt
Signed-off-by: Ingo Molnar -
Impact: Remove the ctrl_update tracer method
With the new quick start/stop method of tracing, the ctrl_update
method is out of date.Signed-off-by: Steven Rostedt
Signed-off-by: Ingo Molnar
06 Nov, 2008
1 commit
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Impact: change where tracing is started up and stopped
Currently, when a new tracer is selected via echo'ing a tracer name into
the current_tracer file, the startup is only done if tracing_enabled is
set to one. If tracing_enabled is changed to zero (by echo'ing 0 into
the tracing_enabled file) a full shutdown is performed.The full startup and shutdown of a tracer can be expensive and the
user can lose out traces when echo'ing in 0 to the tracing_enabled file,
because the process takes too long. There can also be places that
the user would like to start and stop the tracer several times and
doing the full startup and shutdown of a tracer might be too expensive.This patch performs the full startup and shutdown when a tracer is
selected. It also adds a way to do a quick start or stop of a tracer.
The quick version is just a flag that prevents the tracing from
taking place, but the overhead of the code is still there.For example, the startup of a tracer may enable tracepoints, or enable
the function tracer. The stop and start will just set a flag to
have the tracer ignore the calls when the tracepoint or function trace
is called. The overhead of the tracer may still be present when
the tracer is stopped, but no tracing will occur. Setting the tracer
to the 'nop' tracer (or any other tracer) will perform the shutdown
of the tracer which will disable the tracepoint or disable the
function tracer.The tracing_enabled file will simply start or stop tracing.
This change is all internal. The end result for the user should be the same
as before. If tracing_enabled is not set, no trace will happen.
If tracing_enabled is set, then the trace will happen. The tracing_enabled
variable is static between tracers. Enabling tracing_enabled and
going to another tracer will keep tracing_enabled enabled. Same
is true with disabling tracing_enabled.This patch will now provide a fast start/stop method to the users
for enabling or disabling tracing.Note: There were two methods to the struct tracer that were never
used: The methods start and stop. These were to be used as a hook
to the reading of the trace output, but ended up not being
necessary. These two methods are now used to enable the start
and stop of each tracer, in case the tracer needs to do more than
just not write into the buffer. For example, the irqsoff tracer
must stop recording max latencies when tracing is stopped.Signed-off-by: Steven Rostedt
Signed-off-by: Ingo Molnar
21 Oct, 2008
1 commit
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To avoid further confusion between the ftrace infrastructure and the
function tracer. This patch renames the "ftrace" function tracer
to "function".Now in available_tracers, instead of "ftrace" there will be "function".
This makes more sense, since people will not know exactly what the
"ftrace" tracer does.Signed-off-by: Steven Rostedt
Signed-off-by: Ingo Molnar
14 Oct, 2008
1 commit
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This patch ports ftrace over to the new ring buffer.
Signed-off-by: Steven Rostedt
Signed-off-by: Ingo Molnar
11 Jul, 2008
1 commit
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This is more of a clean up. Currently the function tracer initializes the
tracer with which ever CPU was last used for tracing. This value isn't
realy useful for function tracing, but at least it should be something other
than a random number.Signed-off-by: Steven Rostedt
Cc: Steven Rostedt
Cc: Peter Zijlstra
Cc: Andrew Morton
Signed-off-by: Ingo Molnar
27 May, 2008
1 commit
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The new work with converting the trace hooks over to markers broke the
command line recording of ftrace. This patch fixes it again.Signed-off-by: Steven Rostedt
Cc: Peter Zijlstra
Cc: Mathieu Desnoyers
Signed-off-by: Thomas Gleixner
24 May, 2008
6 commits
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In cleaning up of the sched_switch code, the function trace recording
of task comms was removed. This patch adds back the recording of comms
for function trace. The output of ftrace now has the task comm instead
of .Signed-off-by: Steven Rostedt
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
now that we have a kbuild method for notrace, no need to pollute the
C code with the annotations.Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
rename and uninline now() to ftrace_now().
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
This is a simple trace that uses the ftrace infrastructure. It is
designed to be fast and small, and easy to use. It is useful to
record things that happen over a very short period of time, and
not to analyze the system in general.Updates:
available_tracers
"function" is added to this file.current_tracer
To enable the function tracer:echo function > /debugfs/tracing/current_tracer
To disable the tracer:
echo disable > /debugfs/tracing/current_tracer
The output of the function_trace file is as follows
"echo noverbose > /debugfs/tracing/iter_ctrl"
preemption latency trace v1.1.5 on 2.6.24-rc7-tst
Signed-off-by: Ingo Molnar
--------------------------------------------------------------------
latency: 0 us, #419428/4361791, CPU#1 | (M:desktop VP:0, KP:0, SP:0 HP:0 #P:4)
-----------------
| task: -0 (uid:0 nice:0 policy:0 rt_prio:0)
-----------------_------=> CPU#
/ _-----=> irqs-off
| / _----=> need-resched
|| / _---=> hardirq/softirq
||| / _--=> preempt-depth
|||| /
||||| delay
cmd pid ||||| time | caller
\ / ||||| \ | /
swapper-0 0d.h. 1595128us+: set_normalized_timespec+0x8/0x2d (ktime_get_ts+0x4a/0x4e )
swapper-0 0d.h. 1595131us+: _spin_lock+0x8/0x18 (hrtimer_interrupt+0x6e/0x1b0 )Or with verbose turned on:
"echo verbose > /debugfs/tracing/iter_ctrl"
preemption latency trace v1.1.5 on 2.6.24-rc7-tst
--------------------------------------------------------------------
latency: 0 us, #419428/4361791, CPU#1 | (M:desktop VP:0, KP:0, SP:0 HP:0 #P:4)
-----------------
| task: -0 (uid:0 nice:0 policy:0 rt_prio:0)
-----------------swapper 0 0 9 00000000 00000000 [f3675f41] 1595.128ms (+0.003ms): set_normalized_timespec+0x8/0x2d (ktime_get_ts+0x4a/0x4e )
swapper 0 0 9 00000000 00000001 [f3675f45] 1595.131ms (+0.003ms): _spin_lock+0x8/0x18 (hrtimer_interrupt+0x6e/0x1b0 )
swapper 0 0 9 00000000 00000002 [f3675f48] 1595.135ms (+0.003ms): _spin_lock+0x8/0x18 (hrtimer_interrupt+0x6e/0x1b0 )The "trace" file is not affected by the verbose mode, but is by the symonly.
echo "nosymonly" > /debugfs/tracing/iter_ctrl
tracer:
[ 81.479967] CPU 0: bash:3154 register_ftrace_function+0x5f/0x66
[ 81.479967] CPU 0: bash:3154 _spin_unlock_irqrestore+0x3e/0x5a
[ 81.479968] CPU 0: bash:3154 sub_preempt_count+0x30/0x7a
[ 81.479968] CPU 0: bash:3154 vfs_write+0x11d/0x155
[ 81.479968] CPU 0: bash:3154 dnotify_parent+0x2d/0x78
[ 81.479969] CPU 0: bash:3154 _spin_lock+0x1b/0x70
[ 81.479969] CPU 0: bash:3154 add_preempt_count+0x3e/0x77echo "symonly" > /debugfs/tracing/iter_ctrl
tracer:
[ 81.479913] CPU 0: bash:3154 register_ftrace_function+0x5f/0x66
Signed-off-by: Arnaldo Carvalho de Melo
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
