Commit Graph

42 Commits

Author SHA1 Message Date
Frederic Weisbecker
0cf53ff62b tracing: keep the tracing buffer after self-test failure
Instead of using ftrace_dump_on_oops, it's far more convenient
to have the trace leading up to a self-test failure available
in /debug/tracing/trace.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1237694675-23509-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-22 15:17:21 +01:00
Frederic Weisbecker
cf586b61f8 tracing/function-graph-tracer: prevent hangs during self-tests
Impact: detect tracing related hangs

Sometimes, with some configs, the function graph tracer can make
the timer interrupt too much slow, hanging the kernel in an endless
loop of timer interrupts servicing.

As suggested by Ingo, this patch brings a watchdog which stops the
selftest after a defined number of functions traced, definitely
disabling this tracer.

For those who want to debug the cause of the function graph trace
hang, you can pass the ftrace_dump_on_oops kernel parameter to dump
the traces after this hang detection.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1237694675-23509-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-22 14:06:40 +01:00
Frederic Weisbecker
4903620034 tracing/ftrace: stop {irqs, preempt}soff tracers when tracing is stopped
Impact: fix a selftest warning

In some cases, it's possible to see the following warning on irqsoff
tracer selftest:

[    4.640003] Testing tracer irqsoff: <4>------------[ cut here ]------------
[    4.653562] WARNING: at kernel/trace/trace.c:458 update_max_tr_single+0x9a/0xc4()
[    4.660000] Hardware name: System Product Name
[    4.660000] Modules linked in:
[    4.660000] Pid: 301, comm: kstop/1 Not tainted 2.6.29-rc8-tip #35837
[    4.660000] Call Trace:
[    4.660000]  [<4014b588>] warn_slowpath+0x79/0x8f
[    4.660000]  [<402d6949>] ? put_dec+0x64/0x6b
[    4.660000]  [<40162b56>] ? getnstimeofday+0x58/0xdd
[    4.660000]  [<40162210>] ? clocksource_read+0x3/0xf
[    4.660000]  [<4015eb44>] ? ktime_set+0x8/0x34
[    4.660000]  [<4014101a>] ? balance_runtime+0x8/0x56
[    4.660000]  [<405f6f11>] ? _spin_lock+0x3/0x10
[    4.660000]  [<4011f643>] ? ftrace_call+0x5/0x8
[    4.660000]  [<4015d0f1>] ? task_cputime_zero+0x3/0x27
[    4.660000]  [<40190ee7>] ? cpupri_set+0x90/0xcb
[    4.660000]  [<405f7208>] ? _spin_lock_irqsave+0x22/0x34
[    4.660000]  [<40190f12>] ? cpupri_set+0xbb/0xcb
[    4.660000]  [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
[    4.660000]  [<4018493f>] ? ring_buffer_reset_cpu+0x27/0x51
[    4.660000]  [<405f7208>] ? _spin_lock_irqsave+0x22/0x34
[    4.660000]  [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51
[    4.660000]  [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
[    4.660000]  [<4018cc29>] ? trace_hardirqs_off+0x1a/0x1c
[    4.660000]  [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
[    4.660000]  [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51
[    4.660000]  [<401850f3>] ? cpumask_next+0x15/0x18
[    4.660000]  [<4018a41f>] update_max_tr_single+0x9a/0xc4
[    4.660000]  [<4014e5fe>] ? exit_notify+0x16/0xf2
[    4.660000]  [<4018cd13>] check_critical_timing+0xcc/0x11e
[    4.660000]  [<4014e5fe>] ? exit_notify+0x16/0xf2
[    4.660000]  [<4014e5fe>] ? exit_notify+0x16/0xf2
[    4.660000]  [<4018cdf1>] stop_critical_timing+0x8c/0x9f
[    4.660000]  [<4014e5c4>] ? forget_original_parent+0xac/0xd0
[    4.660000]  [<4018ce3a>] trace_hardirqs_on+0x1a/0x1c
[    4.660000]  [<4014e5c4>] forget_original_parent+0xac/0xd0
[    4.660000]  [<4014e5fe>] exit_notify+0x16/0xf2
[    4.660000]  [<4014e8a5>] do_exit+0x1cb/0x225
[    4.660000]  [<4015c72b>] ? kthread+0x0/0x69
[    4.660000]  [<4011f61d>] kernel_thread_helper+0xd/0x10
[    4.660000] ---[ end trace a7919e7f17c0a725 ]---
[    4.660164] .. no entries found ..FAILED!

During the selftest of irqsoff tracer, we do that:

	/* disable interrupts for a bit */
	local_irq_disable();
	udelay(100);
	local_irq_enable();
	/* stop the tracing. */
	tracing_stop();
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);

If a callsite performs a new max delay with irqs off just after
tracing_stop, update_max_tr_single() -> ring_buffer_swap_cpu()
will be called with the buffers disabled by tracing_stop(), hence
the warning, then ring_buffer_swap_cpu() return -EAGAIN and
update_max_tr_single() complains.

Fix it by also stopping the tracer before stopping the tracing globally.
A similar situation can happen with preemptoff and preemptirqsoff tracers
where we apply the same fix.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1237325938-5240-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18 10:12:38 +01:00
Frederic Weisbecker
ac1d52d0b8 tracing/ftrace: fix double calls to tracing_start()
Impact: fix a warning during preemptirqsoff selftests

When the preemptirqsoff selftest fails, we see the following
warning:

[    6.050000] Testing tracer preemptirqsoff: .. no entries found ..
------------[ cut here ]------------
[    6.060000] WARNING: at kernel/trace/trace.c:688 tracing_start+0x67/0xd3()
[    6.060000] Modules linked in:
[    6.060000] Pid: 1, comm: swapper Tainted: G
[    6.060000] Call Trace:
[    6.060000]  [<ffffffff802460ff>] warn_slowpath+0xb1/0x100
[    6.060000]  [<ffffffff802a8f5b>] ? trace_preempt_on+0x35/0x4b
[    6.060000]  [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
[    6.060000]  [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
[    6.060000]  [<ffffffff80271e0b>] ? __lock_acquired+0xe6/0x1f2
[    6.060000]  [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
[    6.060000]  [<ffffffff802a3831>] tracing_start+0x67/0xd3
[    6.060000]  [<ffffffff802a8ace>] ? irqsoff_tracer_reset+0x2d/0x57
[    6.060000]  [<ffffffff802a4d1c>] trace_selftest_startup_preemptirqsoff+0x1c8/0x1f1
[    6.060000]  [<ffffffff802a4798>] register_tracer+0x12f/0x241
[    6.060000]  [<ffffffff810250d0>] ? init_irqsoff_tracer+0x0/0x53
[    6.060000]  [<ffffffff8102510b>] init_irqsoff_tracer+0x3b/0x53

This is because in fail case, the preemptirqsoff tracer selftest calls twice
the tracing_start() function:

int
trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
{
        if (!ret && !count) {
                printk(KERN_CONT ".. no entries found ..");
                ret = -1;
                tracing_start(); <-----
                goto out;
        }
        [...]
out:
        trace->reset(tr);
        tracing_start(); <------
        tracing_max_latency = save_max;

        return ret;
}

Since it is well handled in the out path, we don't need the conditional one.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237159961-7447-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-16 09:13:18 +01:00
Steven Rostedt
9cc26a261d tracing: use generic __stringify
Impact: clean up

This removes the custom made STR(x) macros in the tracer and uses
the generic __stringify macro instead.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:05 -04:00
Ingo Molnar
40999096e8 Merge branches 'tracing/blktrace', 'tracing/ftrace' and 'tracing/urgent' into tracing/core 2009-02-19 10:20:17 +01:00
Steven Rostedt
4b3e3d2284 tracing: limit the number of loops the ring buffer self test can make
Impact: prevent deadlock if ring buffer gets corrupted

This patch adds a paranoid check to make sure the ring buffer consumer
does not go into an infinite loop. Since the ring buffer has been set
to read only, the consumer should not loop for more than the ring buffer
size. A check is added to make sure the consumer does not loop more than
the ring buffer size.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-18 22:50:01 -05:00
Steven Rostedt
0c5119c1e6 tracing: disable tracing while testing ring buffer
Impact: fix to prevent hard lockup on self tests

If one of the tracers are broken and is constantly filling the ring
buffer while the test of the ring buffer is running, it will hang
the box. The reason is that the test is a consumer that will not
stop till the ring buffer is empty. But if the tracer is broken and
is constantly producing input to the buffer, this test will never
end. The result is a lockup of the box.

This happened when KALLSYMS was not defined and the dynamic ftrace
test constantly filled the ring buffer, because the filter failed
and all functions were being traced. Something was being called
that constantly filled the buffer.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-18 22:04:01 -05:00
Wenji Huang
73d8b8bc4f tracing: fix typing mistake in hint message and comments
Impact: cleanup

Fix incorrect hint message in code and typos in comments.

Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-17 12:38:24 -05:00
Wenji Huang
d2ef7c2f0f tracing: fix the return value of trace selftest
This patch is to fix the return value of trace_selftest_startup_sysprof
and trace_selftest_startup_branch on failure.

Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-17 12:38:24 -05:00
Frederic Weisbecker
7447dce96f tracing/function-graph-tracer: provide a selftest for the function graph tracer
Making it more easy to do a basic regression test for this tracer.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09 10:51:37 +01:00
Arnaldo Carvalho de Melo
b6f11df26f trace: Call tracing_reset_online_cpus before tracer->init()
Impact: cleanup

To make it easy for ftrace plugin writers, as this was open coded in
the existing plugins

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Frédéric Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-06 01:01:41 +01:00
Ingo Molnar
a103e2ab73 tracing/selftest: remove TRACE_CONT reference
Impact: build fix

TRACE_CONT is gone - fix up the self-test too.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 15:07:47 +01:00
Frederic Weisbecker
1c80025a49 tracing/ftrace: change the type of the init() callback
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 <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-16 07:55:23 +01:00
Steven Rostedt
d51ad7ac48 ftrace: replace raw_local_irq_save with local_irq_save
Impact: fix lockdep disabling itself when function tracing is enabled

The raw_local_irq_saves used in ftrace is causing problems with
lockdep. (it thinks the irq flags are out of sync and disables
itself with a warning)

The raw ops here are not needed, and the normal local_irq_save is fine.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-16 07:35:37 +01:00
Steven Rostedt
80e5ea4506 ftrace: add tracer called branch
Impact: added new branch tracer

Currently the tracing of branch profiling (unlikelys and likelys hit)
is only activated by the iter_ctrl. This patch adds a tracer called
"branch" that will just trace the branch profiling. The advantage
of adding this tracer is that it can be added to the ftrace selftests
on startup.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12 22:28:25 +01:00
Steven Rostedt
769c48eb25 ftrace: force pass of preemptoff selftest
Impact: preemptoff not tested in selftest

Due to the BKL not being preemptable anymore, the selftest of the
preemptoff code can not be tested. It requires that it is called
with preemption enabled, but since the BKL is held, that is no
longer the case.

This patch simply skips those tests if it detects that the context
is not preemptable. The following will now show up in the tests:

Testing tracer preemptoff: can not test ... force PASSED
Testing tracer preemptirqsoff: can not test ... force PASSED

When the BKL is removed, or it becomes preemptable once again, then
the tests will be performed.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:49 +01:00
Steven Rostedt
c76f06945b ftrace: remove trace array ctrl
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 <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:39 +01:00
Steven Rostedt
bbf5b1a0ce ftrace: remove ctrl_update method
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 <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:34 +01:00
Steven Rostedt
cb7be3b2fc ftrace: remove daemon
The ftrace daemon is complex and error prone.  This patch strips it out
of the code.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-23 16:00:22 +02:00
Steven Rostedt
606576ce81 ftrace: rename FTRACE to FUNCTION_TRACER
Due to confusion between the ftrace infrastructure and the gcc profiling
tracer "ftrace", this patch renames the config options from FTRACE to
FUNCTION_TRACER.  The other two names that are offspring from FTRACE
DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same.

This patch was generated mostly by script, and partially by hand.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-20 18:27:03 +02:00
Steven Rostedt
3928a8a2d9 ftrace: make work with new ring buffer
This patch ports ftrace over to the new ring buffer.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:38:57 +02:00
Steven Rostedt
5aa60c6073 ftrace: give time for wakeup test to run
It is possible that the testing thread in the ftrace wakeup test does not
run before we stop the trace. This will cause the trace to fail since nothing
will be in the buffers.

This patch adds a small wait in the wakeup test to allow for the woken task
to run and be traced.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:38:53 +02:00
Steven Noonan
fb1b6d8b51 ftrace: add nop tracer
A no-op tracer which can serve two purposes:

 1. A template for development of a new tracer.
 2. A convenient way to see ftrace_printk() calls without
    an irrelevant trace making the output messy.

[ mingo@elte.hu: resolved conflicts ]
Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:37:43 +02:00
Steven Rostedt
dd0e545f06 ftrace: printk formatting infrastructure
This patch adds a feature that can help kernel developers debug their
code using ftrace.

  int ftrace_printk(const char *fmt, ...);

This records into the ftrace buffer using printf formatting. The entry
size in the buffers are still a fixed length. A new type has been added
that allows for more entries to be used for a single recording.

The start of the print is still the same as the other entries.

It returns the number of characters written to the ftrace buffer.

For example:

Having a module with the following code:

static int __init ftrace_print_test(void)
{
        ftrace_printk("jiffies are %ld\n", jiffies);
        return 0;
}

Gives me:

  insmod-5441  3...1 7569us : ftrace_print_test: jiffies are 4296626666

for the latency_trace file and:

          insmod-5441  [03]  1959.370498: ftrace_print_test jiffies are 4296626666

for the trace file.

Note: Only the infrastructure should go into the kernel. It is to help
facilitate debugging for other kernel developers. Calls to ftrace_printk
is not intended to be left in the kernel, and should be frowned upon just
like scattering printks around in the code.

But having this easily at your fingertips helps the debugging go faster
and bugs be solved quicker.

Maybe later on, we can hook this with markers and have their printf format
be sucked into ftrace output.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:35:19 +02:00
Ingo Molnar
ec1bb60bbf Merge branch 'tracing/sysprof' into auto-ftrace-next 2008-07-10 11:43:08 +02:00
Steven Rostedt
19384c0314 ftrace: limit use of check pages
The check_pages function is called often enough that it can cause problems
with trace outputs or even bringing the system to a halt.

This patch limits the check_pages to the places that are most likely to
have problems. The check is made at the flip between the global array and
the max save array, as well as when the size of the buffers changes and
the self tests.

This patch also removes the BUG_ON from check_pages and replaces it with
a WARN_ON and disabling of the tracer.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: pq@iki.fi
Cc: proski@gnu.org
Cc: sandmann@redhat.com
Cc: a.p.zijlstra@chello.nl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-26 22:39:45 +02:00
Ingo Molnar
ef4ab15ff3 ftrace: make sysprof dependent on x86 for now
that's the only tested platform for now. If there's interest we
can make it generic easily.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 23:40:01 +02:00
Ingo Molnar
a6dd24f8d0 ftrace: sysprof-plugin, add self-tests
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 23:39:38 +02:00
Steven Rostedt
4e491d14f2 ftrace: support for PowerPC
This patch adds full support for ftrace for PowerPC (both 64 and 32 bit).
This includes dynamic tracing and function filtering.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 22:43:11 +02:00
Steven Rostedt
05bd68c514 ftrace: user proper API for setting RT prios in selftest
The wakeup selftest used an internal API for setting the test task priority.
This patch fixes it to use the proper API for performing such a task.

Thanks goes to Randy Dunlap for pointing out this build failure.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 21:49:42 +02:00
Steven Rostedt
30afdcb1de ftrace: selftest protect againt max flip
There is a slight race condition in the selftest where the max update
of the wakeup and irqs/preemption off tests can be doing a max update as
the buffers are being tested. If this happens the system can crash with
a GPF.

This patch adds the max update spinlock around the checking of the
buffers to prevent such a race.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 21:15:59 +02:00
Steven Rostedt
d05cdb25d8 ftrace: fix dynamic ftrace selftest
With the adding of the configuration changes in the Makefile to prevent
tracing of functions in the ftrace code, all tracing of all the ftrace
code has been removed. Unfortunately, one of the selftests, relied on
a function to be traced. With the new change, the function was no longer
traced and the test failed.

This patch separates out the test function into its own file so that
we can add the "-pg" flag to the compilation of that function and the
adding of the mcount call to that function.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 21:13:23 +02:00
Steven Rostedt
06fa75ab56 ftrace: add TRACE_STACK and TRACE_SPECIAL to selftest validation
The selftest validation code checks for valid entries in the trace buffer.
TRACE_STACK and TRACE_SPECIAL have been added to the code but not to
the validator. This patch adds the two to prevent them from flagging a
failure in the selftest.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 21:13:12 +02:00
Ingo Molnar
57422797dc ftrace: add wakeup events to sched tracer
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 21:04:06 +02:00
Ingo Molnar
e309b41dd6 ftrace: remove notrace
now that we have a kbuild method for notrace, no need to pollute the
C code with the annotations.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 20:58:28 +02:00
Ingo Molnar
9ff9cdb2d3 ftrace: cleanups
clean up recent code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 20:56:05 +02:00
Steven Rostedt
4eebcc81a3 ftrace: disable tracing on failure
Since ftrace touches practically every function. If we detect any
anomaly, we want to fully disable ftrace. This patch adds code
to try shutdown ftrace as much as possible without doing any more
harm is something is detected not quite correct.

This only kills ftrace, this patch does have checks for other parts of
the tracer (irqsoff, wakeup, etc.).

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 20:54:16 +02:00
Steven Rostedt
08bafa0efc ftrace: disable all tracers on corrupted buffer
If the trace buffer is detected to be corrupted, then we
disable all tracers.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 20:41:22 +02:00
Steven Rostedt
77a2b37d22 ftrace: startup tester on dynamic tracing.
This patch adds a startup self test on dynamic code modification
and filters. The test filters on a specific function, makes sure that
no other function is traced, exectutes the function, then makes sure that
the function is traced.

This patch also fixes a slight bug with the ftrace selftest, where
tracer_enabled was not being set.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 20:41:06 +02:00
Ingo Molnar
c7aafc5497 ftrace: cleanups
factor out code and clean it up.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 20:40:46 +02:00
Steven Rostedt
60a11774b3 ftrace: add self-tests
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 20:40:36 +02:00