[PATCH 0/3] ftrace updates for tip

[PATCH 0/3] ftrace updates for tip

[Steven Rostedt]

[
  I added a bit more people to the Cc so that they are aware
  of the pending renames that are coming.

   Namely, trace_entries will be renamed to buffer_size
           iter_ctrl will be renamed to trace_options
]

Ingo,

The following patches are in:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git

    branch: tip/devel


Steven Rostedt (3):
      ftrace: rename trace_entries to buffer_size
      ftrace: rename iter_ctrl to trace_options
      ftrace: CPU buffer start annotation clean ups

----
 Documentation/ftrace.txt |   32 ++++++++++++++++----------------
 kernel/trace/trace.c     |   38 ++++++++++++++++++++++++++------------
 kernel/trace/trace.h     |    1 +
 3 files changed, 43 insertions(+), 28 deletions(-)

Re: [PATCH 0/3] ftrace updates for tip

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> [
>   I added a bit more people to the Cc so that they are aware
>   of the pending renames that are coming.
> 
>    Namely, trace_entries will be renamed to buffer_size
>            iter_ctrl will be renamed to trace_options
> ]
> 
> Ingo,
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: tip/devel
> 
> 
> Steven Rostedt (3):
>       ftrace: rename trace_entries to buffer_size
>       ftrace: rename iter_ctrl to trace_options
>       ftrace: CPU buffer start annotation clean ups

i've applied them to tip/tracing/ftrace, with some small changes:

 12ef7d4: ftrace: CPU buffer start annotation clean ups
 ee6bce5: ftrace: rename iter_ctrl to trace_options
 1696b2b: ftrace: show buffer size in kilobytes
 a94c80e: ftrace: rename trace_entries to buffer_size_kb

as per Arjan's suggestion i changed buffer_size to buffer_size_kb - 
and also removed the kilobytes string from its output.

thanks Steve!

	Ingo

[PATCH 0/3] ftrace: updates for tip

[Steven Rostedt]

Ingo,

The following patches are in:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git

    branch: tip/devel


Steven Rostedt (3):
      ftrace: remove condition from ftrace_record_ip
      ftrace: disable ftrace on anomalies in trace start and stop
      ftrace: do not process freed records

----
 kernel/trace/ftrace.c |   91 +++++++++++++++++++++++++++---------------------
 1 files changed, 51 insertions(+), 40 deletions(-)

[PATCH 0/3] ftrace: updates for tip

[Steven Rostedt]

Ingo,

This series has three patches.

The first patch adds a new feature that I've been wanting to have for some
time and Arjan even requested. That is to pick a function and only
trace that function and its children. Dynamic ftrace and function
graph needs to be enabled for this.

To do the above, I added a "trace" flags field in the task structure.
The second patch uses this for the ftrace pid code. It searches for
the task based on the pid and sets the trace flag, then in the
ftrace function caller it only needs to check this flag.

This means we can now trace more than one pid without any more overhead.
It also means that we should be able to use the name space code that
the container guys want us to. But since I'm not very up on the
namespace code, I'm still using just the normal 'pid'. I've Cc'd the
container folks so perhaps they could write up a patch for me ;-)

Note: When writing to the set_ftrace_pid two things happen.
 - The task with the matching pid gets the trace flag set.
 - Any other task has its trace flag cleared.
 #2 needs to be addressed when converting to pid name spaces.
 Just because it is not enough to simply find the matching task.
 It may be good enough to just clear all tasks and then find the
 one that matches.

The last patch makes the function graph tracer honor the set_ftrace_pid.

The following patches are in:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git

    branch: tip/devel


Steven Rostedt (3):
      ftrace: graph of a single function
      ftrace: use task struct trace flag to filter on pid
      ftrace: trace single pid for function graph tracer

----
 include/linux/ftrace.h |   46 +++++++++
 include/linux/sched.h  |    4 +
 kernel/trace/ftrace.c  |  257 +++++++++++++++++++++++++++++++++++++++++++++++-
 kernel/trace/trace.c   |   11 ++
 kernel/trace/trace.h   |   40 +++++++-
 5 files changed, 353 insertions(+), 5 deletions(-)
-- 

Re: [PATCH 0/3] ftrace: updates for tip

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> Ingo,
> 
> This series has three patches.
> 
> The first patch adds a new feature that I've been wanting to have for some
> time and Arjan even requested. That is to pick a function and only
> trace that function and its children. Dynamic ftrace and function
> graph needs to be enabled for this.
> 
> To do the above, I added a "trace" flags field in the task structure.
> The second patch uses this for the ftrace pid code. It searches for
> the task based on the pid and sets the trace flag, then in the
> ftrace function caller it only needs to check this flag.
> 
> This means we can now trace more than one pid without any more overhead.
> It also means that we should be able to use the name space code that
> the container guys want us to. But since I'm not very up on the
> namespace code, I'm still using just the normal 'pid'. I've Cc'd the
> container folks so perhaps they could write up a patch for me ;-)
> 
> Note: When writing to the set_ftrace_pid two things happen.
>  - The task with the matching pid gets the trace flag set.
>  - Any other task has its trace flag cleared.
>  #2 needs to be addressed when converting to pid name spaces.
>  Just because it is not enough to simply find the matching task.
>  It may be good enough to just clear all tasks and then find the
>  one that matches.
> 
> The last patch makes the function graph tracer honor the set_ftrace_pid.
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: tip/devel
> 
> 
> Steven Rostedt (3):
>       ftrace: graph of a single function
>       ftrace: use task struct trace flag to filter on pid
>       ftrace: trace single pid for function graph tracer
> 
> ----
>  include/linux/ftrace.h |   46 +++++++++
>  include/linux/sched.h  |    4 +
>  kernel/trace/ftrace.c  |  257 +++++++++++++++++++++++++++++++++++++++++++++++-
>  kernel/trace/trace.c   |   11 ++
>  kernel/trace/trace.h   |   40 +++++++-
>  5 files changed, 353 insertions(+), 5 deletions(-)
> -- 

pulled, thanks Steve!

These are some very nice changes!

	Ingo

Re: [PATCH 0/3] ftrace: updates for tip

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> Ingo,
> 
> This series has three patches.
> 
> The first patch adds a new feature that I've been wanting to have for 
> some time and Arjan even requested. That is to pick a function and only 
> trace that function and its children. Dynamic ftrace and function graph 
> needs to be enabled for this.
> 
> To do the above, I added a "trace" flags field in the task structure. 
> The second patch uses this for the ftrace pid code. It searches for the 
> task based on the pid and sets the trace flag, then in the ftrace 
> function caller it only needs to check this flag.

Btw., i'd love to see this done via the regular regexp interface though, 
if possible - instead of the add-on interface you added.

( Also perhaps enable to toggle tracing via the /proc/<PID>/ hierarchy - 
  a /proc/<PID>/tracing_enabled switch or so. )

Regarding the filter functions, the basic principle should be 
mathematical set operations, like we have it now: add and remove, union, 
wildcards, etc.

I'd suggest a natural and intuitive extension of the current syntax. 
(while keeping all the current bits)

I already suggested a 'inverse' filter in a previous mail:

  echo "-schedule*" >> set_ftrace_filter

This rule operates on the current set of filter functions: it strikes out 
all existing filter functions that match this pattern.

To handle PIDs, we could do something like:

  echo "sshd-312:schedule" > set_ftrace_filter

This would restrict tracing to the sshd-pid:312 task.

Note: the PID portion of the filter rules still stay separate from the 
function names - we dont want per task function filter rules.

A natural variation would be:

  echo "312:schedule" > set_ftrace_filter

to only specify the PID, or:

  echo "312,313:schedule" > set_ftrace_filter

to specify two PIDs, or:

  echo "sshd:schedule" > set_ftrace_filter

to only specify the 'comm' part, which expands to all PIDs where 
task->comm matches sshd. Another variation would be:

  echo "loop*:schedule" > set_ftrace_filter

that matches all PIDs where task->comm matches loop*.

To specify recursive tracing, we could use something like:

  echo "loop*+schedule" > set_ftrace_filter

the '+' would signal that the 'schedule' function is 'expanded' and all 
its child functions are traced as well.

btw., maybe it makes sense to separate the regexp rule-set from the set 
of functions that we are tracing right now. For example:

  $ echo "schedule*" >  set_ftrace_filter
  $ echo "time*"     >> set_ftrace_filter
  $ echo "sys_*"     >> set_ftrace_filter

  $ cat set_ftrace_filter
  schedule*
  time*
  sys_*

We'd also have a separate, current_ftrace_functions file as well which 
shows all traced functions. (on a global basis - with possible PID filter 
rules added where applicable)

I know this will be hellishly hard to implement, but it would be _very_ 
elegant, and _very_ usable.

What do you think?

	Ingo

Re: [PATCH 0/3] ftrace: updates for tip

[Steven Rostedt]

On Thu, 4 Dec 2008, Ingo Molnar wrote:

> 
> * Steven Rostedt <rostedt@goodmis.org> wrote:
> 
> > Ingo,
> > 
> > This series has three patches.
> > 
> > The first patch adds a new feature that I've been wanting to have for 
> > some time and Arjan even requested. That is to pick a function and only 
> > trace that function and its children. Dynamic ftrace and function graph 
> > needs to be enabled for this.
> > 
> > To do the above, I added a "trace" flags field in the task structure. 
> > The second patch uses this for the ftrace pid code. It searches for the 
> > task based on the pid and sets the trace flag, then in the ftrace 
> > function caller it only needs to check this flag.
> 
> Btw., i'd love to see this done via the regular regexp interface though, 
> if possible - instead of the add-on interface you added.

So would I. Unfortunately the regex is tightly coupled to turning on or 
off the function. This needs all functions enabled because we do not
know which functions the flagged one will call.

I could reuse the regex code if I add a call back to handle what to do on 
a match.  This is a bit more work, and will take some time to do.
If someone else has the time to do it, I would offer suggestions and 
review the code. Right now I do not have the time myself.

> 
> ( Also perhaps enable to toggle tracing via the /proc/<PID>/ hierarchy - 
>   a /proc/<PID>/tracing_enabled switch or so. )
> 
> Regarding the filter functions, the basic principle should be 
> mathematical set operations, like we have it now: add and remove, union, 
> wildcards, etc.
> 
> I'd suggest a natural and intuitive extension of the current syntax. 
> (while keeping all the current bits)
> 
> I already suggested a 'inverse' filter in a previous mail:
> 
>   echo "-schedule*" >> set_ftrace_filter

Ah, I did not see the '>>' that might be easier to do. I think you first
suggested this with a "!sched*" > set_ftrace_filter where the '>' would
truncate. But doing it with append '>>', might work.

> 
> This rule operates on the current set of filter functions: it strikes out 
> all existing filter functions that match this pattern.
> 
> To handle PIDs, we could do something like:
> 
>   echo "sshd-312:schedule" > set_ftrace_filter
> 
> This would restrict tracing to the sshd-pid:312 task.
> 
> Note: the PID portion of the filter rules still stay separate from the 
> function names - we dont want per task function filter rules.

Yep, agreed, A function is traced if the following conditions are true:

- function tracing is enabled
- the function is set to trace (not in set_ftrace_notrace)
- the pid filter is on and the current task has its trace bit set
 or the pid filter is off.
- the function filter is on and the function is in the trace array
 or the function filter is off

> 
> A natural variation would be:
> 
>   echo "312:schedule" > set_ftrace_filter
> 
> to only specify the PID, or:
> 
>   echo "312,313:schedule" > set_ftrace_filter
> 
> to specify two PIDs, or:
> 
>   echo "sshd:schedule" > set_ftrace_filter
> 
> to only specify the 'comm' part, which expands to all PIDs where 
> task->comm matches sshd. Another variation would be:
> 
>   echo "loop*:schedule" > set_ftrace_filter
> 
> that matches all PIDs where task->comm matches loop*.
> 
> To specify recursive tracing, we could use something like:
> 
>   echo "loop*+schedule" > set_ftrace_filter
> 
> the '+' would signal that the 'schedule' function is 'expanded' and all 
> its child functions are traced as well.
> 
> btw., maybe it makes sense to separate the regexp rule-set from the set 
> of functions that we are tracing right now. For example:
> 
>   $ echo "schedule*" >  set_ftrace_filter
>   $ echo "time*"     >> set_ftrace_filter
>   $ echo "sys_*"     >> set_ftrace_filter
> 
>   $ cat set_ftrace_filter
>   schedule*
>   time*
>   sys_*
> 
> We'd also have a separate, current_ftrace_functions file as well which 
> shows all traced functions. (on a global basis - with possible PID filter 
> rules added where applicable)
> 
> I know this will be hellishly hard to implement, but it would be _very_ 
> elegant, and _very_ usable.
> 
> What do you think?

Hmm, that is starting to get quite complex, just to use. This is something 
we need to experiment with to find the best solution. I'd like to know use 
cases first. Currently I have a simple program that forks, traces itself 
and execs code to trace. It is exectued like:

  ./trace-func ls -ltr

to trace "ls -lrt",  this code would become a little more complex with the 
above methods.  But I'm not set in stone in any of these options. I just 
do not want to spend the days coding this to find out no one uses any of 
it but what is already there.

-- Steve

[PATCH 0/3] ftrace: updates for tip

[Steven Rostedt]

This series restructures the output functions of trace.c.

Events are now registered and maintaining an event output is
simplified by keeping the output close together.

The following patches are in:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git

    branch: tip/devel


Steven Rostedt (3):
      ftrace: remove obsolete print continue functionality
      ftrace: set up trace event hash infrastructure
      ftrace: change trace.c to use registered events

----
 kernel/trace/Makefile                |    1 +
 kernel/trace/trace.c                 |  738 ++----------------------------
 kernel/trace/trace.h                 |   15 +-
 kernel/trace/trace_boot.c            |    1 +
 kernel/trace/trace_branch.c          |   53 +++
 kernel/trace/trace_functions_graph.c |    4 +-
 kernel/trace/trace_hw_branches.c     |    1 +
 kernel/trace/trace_mmiotrace.c       |    4 +-
 kernel/trace/trace_output.c          |  832 ++++++++++++++++++++++++++++++++++
 kernel/trace/trace_output.h          |   59 +++
 kernel/trace/trace_power.c           |    1 +
 11 files changed, 990 insertions(+), 719 deletions(-)
-- 

[PATCH 1/3] ftrace: remove obsolete print continue functionality

[Steven Rostedt]

[-- Attachment #1: 0001-ftrace-remove-obsolete-print-continue-functionality.patch --]
[-- Type: text/plain, Size: 6974 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

Impact: clean up

Now that the ring buffer used by ftrace allows for variable length
entries, we do not need the 'cont' feature of the buffer.  This code
makes other parts of ftrace more complex and by removing this it
simplifies the ftrace code.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
 kernel/trace/trace.c                 |   61 ----------------------------------
 kernel/trace/trace.h                 |    7 ----
 kernel/trace/trace_functions_graph.c |    3 --
 kernel/trace/trace_mmiotrace.c       |    3 --
 4 files changed, 0 insertions(+), 74 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b07e34e..481d79b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1765,43 +1765,6 @@ static int task_state_char(unsigned long state)
 	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 }
 
-/*
- * The message is supposed to contain an ending newline.
- * If the printing stops prematurely, try to add a newline of our own.
- */
-void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
-{
-	struct trace_entry *ent;
-	struct trace_field_cont *cont;
-	bool ok = true;
-
-	ent = peek_next_entry(iter, iter->cpu, NULL);
-	if (!ent || ent->type != TRACE_CONT) {
-		trace_seq_putc(s, '\n');
-		return;
-	}
-
-	do {
-		cont = (struct trace_field_cont *)ent;
-		if (ok)
-			ok = (trace_seq_printf(s, "%s", cont->buf) > 0);
-
-		ftrace_disable_cpu();
-
-		if (iter->buffer_iter[iter->cpu])
-			ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
-		else
-			ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
-
-		ftrace_enable_cpu();
-
-		ent = peek_next_entry(iter, iter->cpu, NULL);
-	} while (ent && ent->type == TRACE_CONT);
-
-	if (!ok)
-		trace_seq_putc(s, '\n');
-}
-
 static void test_cpu_buff_start(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
@@ -1834,9 +1797,6 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 	int S, T;
 	int i;
 
-	if (entry->type == TRACE_CONT)
-		return TRACE_TYPE_HANDLED;
-
 	test_cpu_buff_start(iter);
 
 	next_entry = find_next_entry(iter, NULL, &next_ts);
@@ -1922,8 +1882,6 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 
 		seq_print_ip_sym(s, field->ip, sym_flags);
 		trace_seq_printf(s, ": %s", field->buf);
-		if (entry->flags & TRACE_FLAG_CONT)
-			trace_seq_print_cont(s, iter);
 		break;
 	}
 	case TRACE_BRANCH: {
@@ -1968,9 +1926,6 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 
 	entry = iter->ent;
 
-	if (entry->type == TRACE_CONT)
-		return TRACE_TYPE_HANDLED;
-
 	test_cpu_buff_start(iter);
 
 	comm = trace_find_cmdline(iter->ent->pid);
@@ -2076,8 +2031,6 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 
 		seq_print_ip_sym(s, field->ip, sym_flags);
 		trace_seq_printf(s, ": %s", field->buf);
-		if (entry->flags & TRACE_FLAG_CONT)
-			trace_seq_print_cont(s, iter);
 		break;
 	}
 	case TRACE_GRAPH_RET: {
@@ -2124,9 +2077,6 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 
 	entry = iter->ent;
 
-	if (entry->type == TRACE_CONT)
-		return TRACE_TYPE_HANDLED;
-
 	ret = trace_seq_printf(s, "%d %d %llu ",
 		entry->pid, iter->cpu, iter->ts);
 	if (!ret)
@@ -2187,8 +2137,6 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 		trace_assign_type(field, entry);
 
 		trace_seq_printf(s, "# %lx %s", field->ip, field->buf);
-		if (entry->flags & TRACE_FLAG_CONT)
-			trace_seq_print_cont(s, iter);
 		break;
 	}
 	}
@@ -2217,9 +2165,6 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 
 	entry = iter->ent;
 
-	if (entry->type == TRACE_CONT)
-		return TRACE_TYPE_HANDLED;
-
 	SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
 	SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
 	SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
@@ -2283,9 +2228,6 @@ static enum print_line_t print_printk_msg_only(struct trace_iterator *iter)
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	if (entry->flags & TRACE_FLAG_CONT)
-		trace_seq_print_cont(s, iter);
-
 	return TRACE_TYPE_HANDLED;
 }
 
@@ -2296,9 +2238,6 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 
 	entry = iter->ent;
 
-	if (entry->type == TRACE_CONT)
-		return TRACE_TYPE_HANDLED;
-
 	SEQ_PUT_FIELD_RET(s, entry->pid);
 	SEQ_PUT_FIELD_RET(s, entry->cpu);
 	SEQ_PUT_FIELD_RET(s, iter->ts);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index cc7a4f8..3a35738 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -16,7 +16,6 @@ enum trace_type {
 	TRACE_FN,
 	TRACE_CTX,
 	TRACE_WAKE,
-	TRACE_CONT,
 	TRACE_STACK,
 	TRACE_PRINT,
 	TRACE_SPECIAL,
@@ -178,7 +177,6 @@ struct trace_power {
  *  NEED_RESCED		- reschedule is requested
  *  HARDIRQ		- inside an interrupt handler
  *  SOFTIRQ		- inside a softirq handler
- *  CONT		- multiple entries hold the trace item
  */
 enum trace_flag_type {
 	TRACE_FLAG_IRQS_OFF		= 0x01,
@@ -186,7 +184,6 @@ enum trace_flag_type {
 	TRACE_FLAG_NEED_RESCHED		= 0x04,
 	TRACE_FLAG_HARDIRQ		= 0x08,
 	TRACE_FLAG_SOFTIRQ		= 0x10,
-	TRACE_FLAG_CONT			= 0x20,
 };
 
 #define TRACE_BUF_SIZE		1024
@@ -262,7 +259,6 @@ extern void __ftrace_bad_type(void);
 	do {								\
 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
-		IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
@@ -489,9 +485,6 @@ extern int trace_selftest_startup_branch(struct tracer *trace,
 
 extern void *head_page(struct trace_array_cpu *data);
 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
-extern void trace_seq_print_cont(struct trace_seq *s,
-				 struct trace_iterator *iter);
-
 extern int
 seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
 		unsigned long sym_flags);
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 4bf39fc..a02c997 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -589,9 +589,6 @@ print_graph_comment(struct print_entry *trace, struct trace_seq *s,
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	if (ent->flags & TRACE_FLAG_CONT)
-		trace_seq_print_cont(s, iter);
-
 	ret = trace_seq_printf(s, " */\n");
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index fffcb06..83f20ae 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -262,9 +262,6 @@ static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	if (entry->flags & TRACE_FLAG_CONT)
-		trace_seq_print_cont(s, iter);
-
 	return TRACE_TYPE_HANDLED;
 }
 
-- 
1.5.6.5

-- 

[PATCH 2/3] ftrace: set up trace event hash infrastructure

[Steven Rostedt]

[-- Attachment #1: 0002-ftrace-set-up-trace-event-hash-infrastructure.patch --]
[-- Type: text/plain, Size: 20342 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

Impact: introduction of trace event hash

The trace.c file is becoming more difficult to maintain due to the
growing number of events. There is several formats that an event may
be printed. This patch sets up the infrastructure of an event hash to
allow for events to register how they should be printed.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
 kernel/trace/Makefile                |    1 +
 kernel/trace/trace.c                 |  275 +-------------------------
 kernel/trace/trace.h                 |    8 +-
 kernel/trace/trace_boot.c            |    1 +
 kernel/trace/trace_functions_graph.c |    1 +
 kernel/trace/trace_hw_branches.c     |    1 +
 kernel/trace/trace_mmiotrace.c       |    1 +
 kernel/trace/trace_output.c          |  365 ++++++++++++++++++++++++++++++++++
 kernel/trace/trace_output.h          |   43 ++++
 kernel/trace/trace_power.c           |    1 +
 10 files changed, 416 insertions(+), 281 deletions(-)
 create mode 100644 kernel/trace/trace_output.c
 create mode 100644 kernel/trace/trace_output.h

diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 349d5a9..549f93c 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o
 obj-$(CONFIG_RING_BUFFER) += ring_buffer.o
 
 obj-$(CONFIG_TRACING) += trace.o
+obj-$(CONFIG_TRACING) += trace_output.o
 obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
 obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o
 obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 481d79b..707340f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -38,6 +38,7 @@
 #include <linux/irqflags.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 #define TRACE_BUFFER_FLAGS	(RB_FL_OVERWRITE)
 
@@ -330,132 +331,6 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 	tracing_record_cmdline(current);
 }
 
-/**
- * trace_seq_printf - sequence printing of trace information
- * @s: trace sequence descriptor
- * @fmt: printf format string
- *
- * The tracer may use either sequence operations or its own
- * copy to user routines. To simplify formating of a trace
- * trace_seq_printf is used to store strings into a special
- * buffer (@s). Then the output may be either used by
- * the sequencer or pulled into another buffer.
- */
-int
-trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
-{
-	int len = (PAGE_SIZE - 1) - s->len;
-	va_list ap;
-	int ret;
-
-	if (!len)
-		return 0;
-
-	va_start(ap, fmt);
-	ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
-	va_end(ap);
-
-	/* If we can't write it all, don't bother writing anything */
-	if (ret >= len)
-		return 0;
-
-	s->len += ret;
-
-	return len;
-}
-
-/**
- * trace_seq_puts - trace sequence printing of simple string
- * @s: trace sequence descriptor
- * @str: simple string to record
- *
- * The tracer may use either the sequence operations or its own
- * copy to user routines. This function records a simple string
- * into a special buffer (@s) for later retrieval by a sequencer
- * or other mechanism.
- */
-static int
-trace_seq_puts(struct trace_seq *s, const char *str)
-{
-	int len = strlen(str);
-
-	if (len > ((PAGE_SIZE - 1) - s->len))
-		return 0;
-
-	memcpy(s->buffer + s->len, str, len);
-	s->len += len;
-
-	return len;
-}
-
-static int
-trace_seq_putc(struct trace_seq *s, unsigned char c)
-{
-	if (s->len >= (PAGE_SIZE - 1))
-		return 0;
-
-	s->buffer[s->len++] = c;
-
-	return 1;
-}
-
-static int
-trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
-{
-	if (len > ((PAGE_SIZE - 1) - s->len))
-		return 0;
-
-	memcpy(s->buffer + s->len, mem, len);
-	s->len += len;
-
-	return len;
-}
-
-#define MAX_MEMHEX_BYTES	8
-#define HEX_CHARS		(MAX_MEMHEX_BYTES*2 + 1)
-
-static int
-trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
-{
-	unsigned char hex[HEX_CHARS];
-	unsigned char *data = mem;
-	int i, j;
-
-#ifdef __BIG_ENDIAN
-	for (i = 0, j = 0; i < len; i++) {
-#else
-	for (i = len-1, j = 0; i >= 0; i--) {
-#endif
-		hex[j++] = hex_asc_hi(data[i]);
-		hex[j++] = hex_asc_lo(data[i]);
-	}
-	hex[j++] = ' ';
-
-	return trace_seq_putmem(s, hex, j);
-}
-
-static int
-trace_seq_path(struct trace_seq *s, struct path *path)
-{
-	unsigned char *p;
-
-	if (s->len >= (PAGE_SIZE - 1))
-		return 0;
-	p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
-	if (!IS_ERR(p)) {
-		p = mangle_path(s->buffer + s->len, p, "\n");
-		if (p) {
-			s->len = p - s->buffer;
-			return 1;
-		}
-	} else {
-		s->buffer[s->len++] = '?';
-		return 1;
-	}
-
-	return 0;
-}
-
 static void
 trace_seq_reset(struct trace_seq *s)
 {
@@ -1473,154 +1348,6 @@ static void s_stop(struct seq_file *m, void *p)
 	mutex_unlock(&trace_types_lock);
 }
 
-#ifdef CONFIG_KRETPROBES
-static inline const char *kretprobed(const char *name)
-{
-	static const char tramp_name[] = "kretprobe_trampoline";
-	int size = sizeof(tramp_name);
-
-	if (strncmp(tramp_name, name, size) == 0)
-		return "[unknown/kretprobe'd]";
-	return name;
-}
-#else
-static inline const char *kretprobed(const char *name)
-{
-	return name;
-}
-#endif /* CONFIG_KRETPROBES */
-
-static int
-seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
-{
-#ifdef CONFIG_KALLSYMS
-	char str[KSYM_SYMBOL_LEN];
-	const char *name;
-
-	kallsyms_lookup(address, NULL, NULL, NULL, str);
-
-	name = kretprobed(str);
-
-	return trace_seq_printf(s, fmt, name);
-#endif
-	return 1;
-}
-
-static int
-seq_print_sym_offset(struct trace_seq *s, const char *fmt,
-		     unsigned long address)
-{
-#ifdef CONFIG_KALLSYMS
-	char str[KSYM_SYMBOL_LEN];
-	const char *name;
-
-	sprint_symbol(str, address);
-	name = kretprobed(str);
-
-	return trace_seq_printf(s, fmt, name);
-#endif
-	return 1;
-}
-
-#ifndef CONFIG_64BIT
-# define IP_FMT "%08lx"
-#else
-# define IP_FMT "%016lx"
-#endif
-
-int
-seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
-{
-	int ret;
-
-	if (!ip)
-		return trace_seq_printf(s, "0");
-
-	if (sym_flags & TRACE_ITER_SYM_OFFSET)
-		ret = seq_print_sym_offset(s, "%s", ip);
-	else
-		ret = seq_print_sym_short(s, "%s", ip);
-
-	if (!ret)
-		return 0;
-
-	if (sym_flags & TRACE_ITER_SYM_ADDR)
-		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
-	return ret;
-}
-
-static inline int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
-				    unsigned long ip, unsigned long sym_flags)
-{
-	struct file *file = NULL;
-	unsigned long vmstart = 0;
-	int ret = 1;
-
-	if (mm) {
-		const struct vm_area_struct *vma;
-
-		down_read(&mm->mmap_sem);
-		vma = find_vma(mm, ip);
-		if (vma) {
-			file = vma->vm_file;
-			vmstart = vma->vm_start;
-		}
-		if (file) {
-			ret = trace_seq_path(s, &file->f_path);
-			if (ret)
-				ret = trace_seq_printf(s, "[+0x%lx]", ip - vmstart);
-		}
-		up_read(&mm->mmap_sem);
-	}
-	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
-		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
-	return ret;
-}
-
-static int
-seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
-		      unsigned long sym_flags)
-{
-	struct mm_struct *mm = NULL;
-	int ret = 1;
-	unsigned int i;
-
-	if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
-		struct task_struct *task;
-		/*
-		 * we do the lookup on the thread group leader,
-		 * since individual threads might have already quit!
-		 */
-		rcu_read_lock();
-		task = find_task_by_vpid(entry->ent.tgid);
-		if (task)
-			mm = get_task_mm(task);
-		rcu_read_unlock();
-	}
-
-	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
-		unsigned long ip = entry->caller[i];
-
-		if (ip == ULONG_MAX || !ret)
-			break;
-		if (i && ret)
-			ret = trace_seq_puts(s, " <- ");
-		if (!ip) {
-			if (ret)
-				ret = trace_seq_puts(s, "??");
-			continue;
-		}
-		if (!ret)
-			break;
-		if (ret)
-			ret = seq_print_user_ip(s, mm, ip, sym_flags);
-	}
-
-	if (mm)
-		mmput(mm);
-	return ret;
-}
-
 static void print_lat_help_header(struct seq_file *m)
 {
 	seq_puts(m, "#                  _------=> CPU#            \n");
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 3a35738..6bd71fa 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -30,7 +30,7 @@ enum trace_type {
 	TRACE_HW_BRANCHES,
 	TRACE_POWER,
 
-	__TRACE_LAST_TYPE
+	__TRACE_LAST_TYPE,
 };
 
 /*
@@ -484,12 +484,6 @@ extern int trace_selftest_startup_branch(struct tracer *trace,
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 
 extern void *head_page(struct trace_array_cpu *data);
-extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
-extern int
-seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
-		unsigned long sym_flags);
-extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
-				 size_t cnt);
 extern long ns2usecs(cycle_t nsec);
 extern int
 trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args);
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 3ccebde..cb2ff3e 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -11,6 +11,7 @@
 #include <linux/kallsyms.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 static struct trace_array *boot_trace;
 static bool pre_initcalls_finished;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index a02c997..8a34006 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -12,6 +12,7 @@
 #include <linux/fs.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 #define TRACE_GRAPH_INDENT	2
 
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
index b6a3e20..879752b 100644
--- a/kernel/trace/trace_hw_branches.c
+++ b/kernel/trace/trace_hw_branches.c
@@ -14,6 +14,7 @@
 #include <asm/ds.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 
 #define SIZEOF_BTS (1 << 13)
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index 83f20ae..fcec59f 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -11,6 +11,7 @@
 #include <linux/pci.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 struct header_iter {
 	struct pci_dev *dev;
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
new file mode 100644
index 0000000..1f3f800
--- /dev/null
+++ b/kernel/trace/trace_output.c
@@ -0,0 +1,365 @@
+/*
+ * trace_output.c
+ *
+ * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/ftrace.h>
+
+#include "trace_output.h"
+
+/* must be a power of 2 */
+#define EVENT_HASHSIZE	128
+
+static DEFINE_MUTEX(trace_event_mutex);
+static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
+
+static int next_event_type = __TRACE_LAST_TYPE + 1;
+
+/**
+ * trace_seq_printf - sequence printing of trace information
+ * @s: trace sequence descriptor
+ * @fmt: printf format string
+ *
+ * The tracer may use either sequence operations or its own
+ * copy to user routines. To simplify formating of a trace
+ * trace_seq_printf is used to store strings into a special
+ * buffer (@s). Then the output may be either used by
+ * the sequencer or pulled into another buffer.
+ */
+int
+trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
+{
+	int len = (PAGE_SIZE - 1) - s->len;
+	va_list ap;
+	int ret;
+
+	if (!len)
+		return 0;
+
+	va_start(ap, fmt);
+	ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
+	va_end(ap);
+
+	/* If we can't write it all, don't bother writing anything */
+	if (ret >= len)
+		return 0;
+
+	s->len += ret;
+
+	return len;
+}
+
+/**
+ * trace_seq_puts - trace sequence printing of simple string
+ * @s: trace sequence descriptor
+ * @str: simple string to record
+ *
+ * The tracer may use either the sequence operations or its own
+ * copy to user routines. This function records a simple string
+ * into a special buffer (@s) for later retrieval by a sequencer
+ * or other mechanism.
+ */
+int trace_seq_puts(struct trace_seq *s, const char *str)
+{
+	int len = strlen(str);
+
+	if (len > ((PAGE_SIZE - 1) - s->len))
+		return 0;
+
+	memcpy(s->buffer + s->len, str, len);
+	s->len += len;
+
+	return len;
+}
+
+int trace_seq_putc(struct trace_seq *s, unsigned char c)
+{
+	if (s->len >= (PAGE_SIZE - 1))
+		return 0;
+
+	s->buffer[s->len++] = c;
+
+	return 1;
+}
+
+int trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
+{
+	if (len > ((PAGE_SIZE - 1) - s->len))
+		return 0;
+
+	memcpy(s->buffer + s->len, mem, len);
+	s->len += len;
+
+	return len;
+}
+
+int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
+{
+	unsigned char hex[HEX_CHARS];
+	unsigned char *data = mem;
+	int i, j;
+
+#ifdef __BIG_ENDIAN
+	for (i = 0, j = 0; i < len; i++) {
+#else
+	for (i = len-1, j = 0; i >= 0; i--) {
+#endif
+		hex[j++] = hex_asc_hi(data[i]);
+		hex[j++] = hex_asc_lo(data[i]);
+	}
+	hex[j++] = ' ';
+
+	return trace_seq_putmem(s, hex, j);
+}
+
+int trace_seq_path(struct trace_seq *s, struct path *path)
+{
+	unsigned char *p;
+
+	if (s->len >= (PAGE_SIZE - 1))
+		return 0;
+	p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
+	if (!IS_ERR(p)) {
+		p = mangle_path(s->buffer + s->len, p, "\n");
+		if (p) {
+			s->len = p - s->buffer;
+			return 1;
+		}
+	} else {
+		s->buffer[s->len++] = '?';
+		return 1;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_KRETPROBES
+static inline const char *kretprobed(const char *name)
+{
+	static const char tramp_name[] = "kretprobe_trampoline";
+	int size = sizeof(tramp_name);
+
+	if (strncmp(tramp_name, name, size) == 0)
+		return "[unknown/kretprobe'd]";
+	return name;
+}
+#else
+static inline const char *kretprobed(const char *name)
+{
+	return name;
+}
+#endif /* CONFIG_KRETPROBES */
+
+static int
+seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
+{
+#ifdef CONFIG_KALLSYMS
+	char str[KSYM_SYMBOL_LEN];
+	const char *name;
+
+	kallsyms_lookup(address, NULL, NULL, NULL, str);
+
+	name = kretprobed(str);
+
+	return trace_seq_printf(s, fmt, name);
+#endif
+	return 1;
+}
+
+static int
+seq_print_sym_offset(struct trace_seq *s, const char *fmt,
+		     unsigned long address)
+{
+#ifdef CONFIG_KALLSYMS
+	char str[KSYM_SYMBOL_LEN];
+	const char *name;
+
+	sprint_symbol(str, address);
+	name = kretprobed(str);
+
+	return trace_seq_printf(s, fmt, name);
+#endif
+	return 1;
+}
+
+#ifndef CONFIG_64BIT
+# define IP_FMT "%08lx"
+#else
+# define IP_FMT "%016lx"
+#endif
+
+int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
+		      unsigned long ip, unsigned long sym_flags)
+{
+	struct file *file = NULL;
+	unsigned long vmstart = 0;
+	int ret = 1;
+
+	if (mm) {
+		const struct vm_area_struct *vma;
+
+		down_read(&mm->mmap_sem);
+		vma = find_vma(mm, ip);
+		if (vma) {
+			file = vma->vm_file;
+			vmstart = vma->vm_start;
+		}
+		if (file) {
+			ret = trace_seq_path(s, &file->f_path);
+			if (ret)
+				ret = trace_seq_printf(s, "[+0x%lx]",
+						       ip - vmstart);
+		}
+		up_read(&mm->mmap_sem);
+	}
+	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
+		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
+	return ret;
+}
+
+int
+seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
+		      unsigned long sym_flags)
+{
+	struct mm_struct *mm = NULL;
+	int ret = 1;
+	unsigned int i;
+
+	if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
+		struct task_struct *task;
+		/*
+		 * we do the lookup on the thread group leader,
+		 * since individual threads might have already quit!
+		 */
+		rcu_read_lock();
+		task = find_task_by_vpid(entry->ent.tgid);
+		if (task)
+			mm = get_task_mm(task);
+		rcu_read_unlock();
+	}
+
+	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+		unsigned long ip = entry->caller[i];
+
+		if (ip == ULONG_MAX || !ret)
+			break;
+		if (i && ret)
+			ret = trace_seq_puts(s, " <- ");
+		if (!ip) {
+			if (ret)
+				ret = trace_seq_puts(s, "??");
+			continue;
+		}
+		if (!ret)
+			break;
+		if (ret)
+			ret = seq_print_user_ip(s, mm, ip, sym_flags);
+	}
+
+	if (mm)
+		mmput(mm);
+	return ret;
+}
+
+int
+seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
+{
+	int ret;
+
+	if (!ip)
+		return trace_seq_printf(s, "0");
+
+	if (sym_flags & TRACE_ITER_SYM_OFFSET)
+		ret = seq_print_sym_offset(s, "%s", ip);
+	else
+		ret = seq_print_sym_short(s, "%s", ip);
+
+	if (!ret)
+		return 0;
+
+	if (sym_flags & TRACE_ITER_SYM_ADDR)
+		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
+	return ret;
+}
+
+/**
+ * ftrace_find_event - find a registered event
+ * @type: the type of event to look for
+ *
+ * Returns an event of type @type otherwise NULL
+ */
+struct trace_event *ftrace_find_event(int type)
+{
+	struct trace_event *event;
+	struct hlist_node *n;
+	unsigned key;
+
+	key = type & (EVENT_HASHSIZE - 1);
+
+	hlist_for_each_entry_rcu(event, n, &event_hash[key], node) {
+		if (event->type == type)
+			return event;
+	}
+
+	return NULL;
+}
+
+/**
+ * register_ftrace_event - register output for an event type
+ * @event: the event type to register
+ *
+ * Event types are stored in a hash and this hash is used to
+ * find a way to print an event. If the @event->type is set
+ * then it will use that type, otherwise it will assign a
+ * type to use.
+ *
+ * If you assign your own type, please make sure it is added
+ * to the trace_type enum in trace.h, to avoid collisions
+ * with the dynamic types.
+ *
+ * Returns the event type number or zero on error.
+ */
+int register_ftrace_event(struct trace_event *event)
+{
+	unsigned key;
+	int ret = 0;
+
+	mutex_lock(&trace_event_mutex);
+
+	if (!event->type)
+		event->type = next_event_type++;
+	else if (event->type > __TRACE_LAST_TYPE) {
+		printk(KERN_WARNING "Need to add type to trace.h\n");
+		WARN_ON(1);
+	}
+
+	if (ftrace_find_event(event->type))
+		goto out;
+
+	key = event->type & (EVENT_HASHSIZE - 1);
+
+	hlist_add_head_rcu(&event->node, &event_hash[key]);
+
+	ret = event->type;
+ out:
+	mutex_unlock(&trace_event_mutex);
+
+	return ret;
+}
+
+/**
+ * unregister_ftrace_event - remove a no longer used event
+ * @event: the event to remove
+ */
+int unregister_ftrace_event(struct trace_event *event)
+{
+	mutex_lock(&trace_event_mutex);
+	hlist_del(&event->node);
+	mutex_unlock(&trace_event_mutex);
+
+	return 0;
+}
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
new file mode 100644
index 0000000..1fcc76e
--- /dev/null
+++ b/kernel/trace/trace_output.h
@@ -0,0 +1,43 @@
+#ifndef __TRACE_EVENTS_H
+#define __TRACE_EVENTS_H
+
+#include "trace.h"
+
+typedef int (*trace_print_func)(struct trace_seq *s, struct trace_entry *entry,
+				int flags);
+
+struct trace_event {
+	struct hlist_node	node;
+	int			type;
+	trace_print_func	trace;
+	trace_print_func	latency_trace;
+	trace_print_func	raw;
+	trace_print_func	hex;
+	trace_print_func	binary;
+};
+
+extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
+extern int
+seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
+		unsigned long sym_flags);
+extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
+				 size_t cnt);
+int trace_seq_puts(struct trace_seq *s, const char *str);
+int trace_seq_putc(struct trace_seq *s, unsigned char c);
+int trace_seq_putmem(struct trace_seq *s, void *mem, size_t len);
+int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len);
+int trace_seq_path(struct trace_seq *s, struct path *path);
+int seq_print_userip_objs(const struct userstack_entry *entry,
+			  struct trace_seq *s, unsigned long sym_flags);
+int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
+		      unsigned long ip, unsigned long sym_flags);
+
+struct trace_event *ftrace_find_event(int type);
+int register_ftrace_event(struct trace_event *event);
+int unregister_ftrace_event(struct trace_event *event);
+
+#define MAX_MEMHEX_BYTES	8
+#define HEX_CHARS		(MAX_MEMHEX_BYTES*2 + 1)
+
+#endif
+
diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c
index a7172a3..b9b13c3 100644
--- a/kernel/trace/trace_power.c
+++ b/kernel/trace/trace_power.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 static struct trace_array *power_trace;
 static int __read_mostly trace_power_enabled;
-- 
1.5.6.5

-- 

[PATCH 3/3] ftrace: change trace.c to use registered events

[Steven Rostedt]

[-- Attachment #1: 0003-ftrace-change-trace.c-to-use-registered-events.patch --]
[-- Type: text/plain, Size: 26835 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

Impact: rework to use new event register API

Almost every ftrace event has to implement its output display in
trace.c through a different function. Some events did not handle
all the formats (trace, latency-trace, raw, hex, binary), and
this method does not scale well.

This patch converts the format functions to use the event API to
find the event and and print its format. Currently, we have
a print function for trace, latency_trace, raw, hex and binary.
A trace_nop_print is available if the event wants to avoid output
on a particular format.

Perhaps other tracers could use this in the future (like mmiotrace and
function_graph).

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
 kernel/trace/trace.c        |  402 ++++---------------------------------
 kernel/trace/trace_branch.c |   53 +++++
 kernel/trace/trace_output.c |  467 +++++++++++++++++++++++++++++++++++++++++++
 kernel/trace/trace_output.h |   16 ++
 4 files changed, 574 insertions(+), 364 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 707340f..a087add 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1483,15 +1483,6 @@ lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 		trace_seq_puts(s, " : ");
 }
 
-static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
-
-static int task_state_char(unsigned long state)
-{
-	int bit = state ? __ffs(state) + 1 : 0;
-
-	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
-}
-
 static void test_cpu_buff_start(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
@@ -1515,14 +1506,14 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 	struct trace_seq *s = &iter->seq;
 	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
 	struct trace_entry *next_entry;
+	struct trace_event *event;
 	unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 	struct trace_entry *entry = iter->ent;
 	unsigned long abs_usecs;
 	unsigned long rel_usecs;
 	u64 next_ts;
 	char *comm;
-	int S, T;
-	int i;
+	int ret;
 
 	test_cpu_buff_start(iter);
 
@@ -1547,94 +1538,16 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 		lat_print_generic(s, entry, cpu);
 		lat_print_timestamp(s, abs_usecs, rel_usecs);
 	}
-	switch (entry->type) {
-	case TRACE_FN: {
-		struct ftrace_entry *field;
-
-		trace_assign_type(field, entry);
-
-		seq_print_ip_sym(s, field->ip, sym_flags);
-		trace_seq_puts(s, " (");
-		seq_print_ip_sym(s, field->parent_ip, sym_flags);
-		trace_seq_puts(s, ")\n");
-		break;
-	}
-	case TRACE_CTX:
-	case TRACE_WAKE: {
-		struct ctx_switch_entry *field;
-
-		trace_assign_type(field, entry);
-
-		T = task_state_char(field->next_state);
-		S = task_state_char(field->prev_state);
-		comm = trace_find_cmdline(field->next_pid);
-		trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
-				 field->prev_pid,
-				 field->prev_prio,
-				 S, entry->type == TRACE_CTX ? "==>" : "  +",
-				 field->next_cpu,
-				 field->next_pid,
-				 field->next_prio,
-				 T, comm);
-		break;
-	}
-	case TRACE_SPECIAL: {
-		struct special_entry *field;
-
-		trace_assign_type(field, entry);
-
-		trace_seq_printf(s, "# %ld %ld %ld\n",
-				 field->arg1,
-				 field->arg2,
-				 field->arg3);
-		break;
-	}
-	case TRACE_STACK: {
-		struct stack_entry *field;
-
-		trace_assign_type(field, entry);
-
-		for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
-			if (i)
-				trace_seq_puts(s, " <= ");
-			seq_print_ip_sym(s, field->caller[i], sym_flags);
-		}
-		trace_seq_puts(s, "\n");
-		break;
-	}
-	case TRACE_PRINT: {
-		struct print_entry *field;
-
-		trace_assign_type(field, entry);
 
-		seq_print_ip_sym(s, field->ip, sym_flags);
-		trace_seq_printf(s, ": %s", field->buf);
-		break;
-	}
-	case TRACE_BRANCH: {
-		struct trace_branch *field;
-
-		trace_assign_type(field, entry);
-
-		trace_seq_printf(s, "[%s] %s:%s:%d\n",
-				 field->correct ? "  ok  " : " MISS ",
-				 field->func,
-				 field->file,
-				 field->line);
-		break;
+	event = ftrace_find_event(entry->type);
+	if (event && event->latency_trace) {
+		ret = event->latency_trace(s, entry, sym_flags);
+		if (ret)
+			return ret;
+		return TRACE_TYPE_HANDLED;
 	}
-	case TRACE_USER_STACK: {
-		struct userstack_entry *field;
 
-		trace_assign_type(field, entry);
-
-		seq_print_userip_objs(field, s, sym_flags);
-		trace_seq_putc(s, '\n');
-		break;
-	}
-	default:
-		trace_seq_printf(s, "Unknown type %d\n", entry->type);
-	}
+	trace_seq_printf(s, "Unknown type %d\n", entry->type);
 	return TRACE_TYPE_HANDLED;
 }
 
@@ -1643,13 +1556,12 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 	struct trace_seq *s = &iter->seq;
 	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
 	struct trace_entry *entry;
+	struct trace_event *event;
 	unsigned long usec_rem;
 	unsigned long long t;
 	unsigned long secs;
 	char *comm;
 	int ret;
-	int S, T;
-	int i;
 
 	entry = iter->ent;
 
@@ -1671,127 +1583,17 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	switch (entry->type) {
-	case TRACE_FN: {
-		struct ftrace_entry *field;
-
-		trace_assign_type(field, entry);
-
-		ret = seq_print_ip_sym(s, field->ip, sym_flags);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
-						field->parent_ip) {
-			ret = trace_seq_printf(s, " <-");
-			if (!ret)
-				return TRACE_TYPE_PARTIAL_LINE;
-			ret = seq_print_ip_sym(s,
-					       field->parent_ip,
-					       sym_flags);
-			if (!ret)
-				return TRACE_TYPE_PARTIAL_LINE;
-		}
-		ret = trace_seq_printf(s, "\n");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		break;
-	}
-	case TRACE_CTX:
-	case TRACE_WAKE: {
-		struct ctx_switch_entry *field;
-
-		trace_assign_type(field, entry);
-
-		T = task_state_char(field->next_state);
-		S = task_state_char(field->prev_state);
-		ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
-				       field->prev_pid,
-				       field->prev_prio,
-				       S,
-				       entry->type == TRACE_CTX ? "==>" : "  +",
-				       field->next_cpu,
-				       field->next_pid,
-				       field->next_prio,
-				       T);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		break;
-	}
-	case TRACE_SPECIAL: {
-		struct special_entry *field;
-
-		trace_assign_type(field, entry);
-
-		ret = trace_seq_printf(s, "# %ld %ld %ld\n",
-				 field->arg1,
-				 field->arg2,
-				 field->arg3);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		break;
-	}
-	case TRACE_STACK: {
-		struct stack_entry *field;
-
-		trace_assign_type(field, entry);
-
-		for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
-			if (i) {
-				ret = trace_seq_puts(s, " <= ");
-				if (!ret)
-					return TRACE_TYPE_PARTIAL_LINE;
-			}
-			ret = seq_print_ip_sym(s, field->caller[i],
-					       sym_flags);
-			if (!ret)
-				return TRACE_TYPE_PARTIAL_LINE;
-		}
-		ret = trace_seq_puts(s, "\n");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		break;
-	}
-	case TRACE_PRINT: {
-		struct print_entry *field;
-
-		trace_assign_type(field, entry);
-
-		seq_print_ip_sym(s, field->ip, sym_flags);
-		trace_seq_printf(s, ": %s", field->buf);
-		break;
-	}
-	case TRACE_GRAPH_RET: {
-		return print_graph_function(iter);
-	}
-	case TRACE_GRAPH_ENT: {
-		return print_graph_function(iter);
-	}
-	case TRACE_BRANCH: {
-		struct trace_branch *field;
-
-		trace_assign_type(field, entry);
-
-		trace_seq_printf(s, "[%s] %s:%s:%d\n",
-				 field->correct ? "  ok  " : " MISS ",
-				 field->func,
-				 field->file,
-				 field->line);
-		break;
+	event = ftrace_find_event(entry->type);
+	if (event && event->trace) {
+		ret = event->trace(s, entry, sym_flags);
+		if (ret)
+			return ret;
+		return TRACE_TYPE_HANDLED;
 	}
-	case TRACE_USER_STACK: {
-		struct userstack_entry *field;
-
-		trace_assign_type(field, entry);
+	ret = trace_seq_printf(s, "Unknown type %d\n", entry->type);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
 
-		ret = seq_print_userip_objs(field, s, sym_flags);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		ret = trace_seq_putc(s, '\n');
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		break;
-	}
-	}
 	return TRACE_TYPE_HANDLED;
 }
 
@@ -1799,8 +1601,8 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
 	struct trace_entry *entry;
+	struct trace_event *event;
 	int ret;
-	int S, T;
 
 	entry = iter->ent;
 
@@ -1809,86 +1611,26 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	switch (entry->type) {
-	case TRACE_FN: {
-		struct ftrace_entry *field;
-
-		trace_assign_type(field, entry);
-
-		ret = trace_seq_printf(s, "%x %x\n",
-					field->ip,
-					field->parent_ip);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		break;
-	}
-	case TRACE_CTX:
-	case TRACE_WAKE: {
-		struct ctx_switch_entry *field;
-
-		trace_assign_type(field, entry);
-
-		T = task_state_char(field->next_state);
-		S = entry->type == TRACE_WAKE ? '+' :
-			task_state_char(field->prev_state);
-		ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
-				       field->prev_pid,
-				       field->prev_prio,
-				       S,
-				       field->next_cpu,
-				       field->next_pid,
-				       field->next_prio,
-				       T);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		break;
-	}
-	case TRACE_SPECIAL:
-	case TRACE_USER_STACK:
-	case TRACE_STACK: {
-		struct special_entry *field;
-
-		trace_assign_type(field, entry);
-
-		ret = trace_seq_printf(s, "# %ld %ld %ld\n",
-				 field->arg1,
-				 field->arg2,
-				 field->arg3);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-		break;
+	event = ftrace_find_event(entry->type);
+	if (event && event->raw) {
+		ret = event->raw(s, entry, 0);
+		if (ret)
+			return ret;
+		return TRACE_TYPE_HANDLED;
 	}
-	case TRACE_PRINT: {
-		struct print_entry *field;
-
-		trace_assign_type(field, entry);
+	ret = trace_seq_printf(s, "%d ?\n", entry->type);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
 
-		trace_seq_printf(s, "# %lx %s", field->ip, field->buf);
-		break;
-	}
-	}
 	return TRACE_TYPE_HANDLED;
 }
 
-#define SEQ_PUT_FIELD_RET(s, x)				\
-do {							\
-	if (!trace_seq_putmem(s, &(x), sizeof(x)))	\
-		return 0;				\
-} while (0)
-
-#define SEQ_PUT_HEX_FIELD_RET(s, x)			\
-do {							\
-	BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES);	\
-	if (!trace_seq_putmem_hex(s, &(x), sizeof(x)))	\
-		return 0;				\
-} while (0)
-
 static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
 	unsigned char newline = '\n';
 	struct trace_entry *entry;
-	int S, T;
+	struct trace_event *event;
 
 	entry = iter->ent;
 
@@ -1896,47 +1638,10 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 	SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
 	SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
 
-	switch (entry->type) {
-	case TRACE_FN: {
-		struct ftrace_entry *field;
-
-		trace_assign_type(field, entry);
-
-		SEQ_PUT_HEX_FIELD_RET(s, field->ip);
-		SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
-		break;
-	}
-	case TRACE_CTX:
-	case TRACE_WAKE: {
-		struct ctx_switch_entry *field;
-
-		trace_assign_type(field, entry);
-
-		T = task_state_char(field->next_state);
-		S = entry->type == TRACE_WAKE ? '+' :
-			task_state_char(field->prev_state);
-		SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
-		SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
-		SEQ_PUT_HEX_FIELD_RET(s, S);
-		SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
-		SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
-		SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
-		SEQ_PUT_HEX_FIELD_RET(s, T);
-		break;
-	}
-	case TRACE_SPECIAL:
-	case TRACE_USER_STACK:
-	case TRACE_STACK: {
-		struct special_entry *field;
-
-		trace_assign_type(field, entry);
+	event = ftrace_find_event(entry->type);
+	if (event && event->hex)
+		event->hex(s, entry, 0);
 
-		SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
-		SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
-		SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
-		break;
-	}
-	}
 	SEQ_PUT_FIELD_RET(s, newline);
 
 	return TRACE_TYPE_HANDLED;
@@ -1962,6 +1667,7 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
 	struct trace_entry *entry;
+	struct trace_event *event;
 
 	entry = iter->ent;
 
@@ -1969,43 +1675,11 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 	SEQ_PUT_FIELD_RET(s, entry->cpu);
 	SEQ_PUT_FIELD_RET(s, iter->ts);
 
-	switch (entry->type) {
-	case TRACE_FN: {
-		struct ftrace_entry *field;
-
-		trace_assign_type(field, entry);
+	event = ftrace_find_event(entry->type);
+	if (event && event->binary)
+		event->binary(s, entry, 0);
 
-		SEQ_PUT_FIELD_RET(s, field->ip);
-		SEQ_PUT_FIELD_RET(s, field->parent_ip);
-		break;
-	}
-	case TRACE_CTX: {
-		struct ctx_switch_entry *field;
-
-		trace_assign_type(field, entry);
-
-		SEQ_PUT_FIELD_RET(s, field->prev_pid);
-		SEQ_PUT_FIELD_RET(s, field->prev_prio);
-		SEQ_PUT_FIELD_RET(s, field->prev_state);
-		SEQ_PUT_FIELD_RET(s, field->next_pid);
-		SEQ_PUT_FIELD_RET(s, field->next_prio);
-		SEQ_PUT_FIELD_RET(s, field->next_state);
-		break;
-	}
-	case TRACE_SPECIAL:
-	case TRACE_USER_STACK:
-	case TRACE_STACK: {
-		struct special_entry *field;
-
-		trace_assign_type(field, entry);
-
-		SEQ_PUT_FIELD_RET(s, field->arg1);
-		SEQ_PUT_FIELD_RET(s, field->arg2);
-		SEQ_PUT_FIELD_RET(s, field->arg3);
-		break;
-	}
-	}
-	return 1;
+	return TRACE_TYPE_HANDLED;
 }
 
 static int trace_empty(struct trace_iterator *iter)
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 6c00feb..c15222a 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -14,7 +14,9 @@
 #include <linux/hash.h>
 #include <linux/fs.h>
 #include <asm/local.h>
+
 #include "trace.h"
+#include "trace_output.h"
 
 #ifdef CONFIG_BRANCH_TRACER
 
@@ -142,6 +144,49 @@ static void branch_trace_reset(struct trace_array *tr)
 	stop_branch_trace(tr);
 }
 
+static int
+trace_print_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct print_entry *field;
+
+	trace_assign_type(field, entry);
+
+	if (seq_print_ip_sym(s, field->ip, flags))
+		goto partial;
+
+	if (trace_seq_printf(s, ": %s", field->buf))
+		goto partial;
+
+ partial:
+	return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int
+trace_branch_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct trace_branch *field;
+
+	trace_assign_type(field, entry);
+
+	if (trace_seq_printf(s, "[%s] %s:%s:%d\n",
+			     field->correct ? "  ok  " : " MISS ",
+			     field->func,
+			     field->file,
+			     field->line))
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return 0;
+}
+
+static struct trace_event trace_branch_event = {
+	.type	 	= TRACE_BRANCH,
+	.trace		= trace_branch_print,
+	.latency_trace	= trace_branch_print,
+	.raw		= trace_nop_print,
+	.hex		= trace_nop_print,
+	.binary		= trace_nop_print,
+};
+
 struct tracer branch_trace __read_mostly =
 {
 	.name		= "branch",
@@ -154,6 +199,14 @@ struct tracer branch_trace __read_mostly =
 
 __init static int init_branch_trace(void)
 {
+	int ret;
+
+	ret = register_ftrace_event(&trace_branch_event);
+	if (!ret) {
+		printk(KERN_WARNING "Warning: could not register branch events\n");
+		return 1;
+	}
+
 	return register_tracer(&branch_trace);
 }
 
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 1f3f800..df0c25c 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -286,6 +286,15 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 	return ret;
 }
 
+static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
+
+static int task_state_char(unsigned long state)
+{
+	int bit = state ? __ffs(state) + 1 : 0;
+
+	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
+}
+
 /**
  * ftrace_find_event - find a registered event
  * @type: the type of event to look for
@@ -363,3 +372,461 @@ int unregister_ftrace_event(struct trace_event *event)
 
 	return 0;
 }
+
+/*
+ * Standard events
+ */
+
+int
+trace_nop_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	return 0;
+}
+
+/* TRACE_FN */
+static int
+trace_fn_latency(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct ftrace_entry *field;
+
+	trace_assign_type(field, entry);
+
+	if (!seq_print_ip_sym(s, field->ip, flags))
+		goto partial;
+	if (!trace_seq_puts(s, " ("))
+		goto partial;
+	if (!seq_print_ip_sym(s, field->parent_ip, flags))
+		goto partial;
+	if (!trace_seq_puts(s, ")\n"))
+		goto partial;
+
+	return 0;
+
+ partial:
+	return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int
+trace_fn_trace(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct ftrace_entry *field;
+
+	trace_assign_type(field, entry);
+
+	if (!seq_print_ip_sym(s, field->ip, flags))
+		goto partial;
+
+	if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
+		if (!trace_seq_printf(s, " <-"))
+			goto partial;
+		if (!seq_print_ip_sym(s,
+				      field->parent_ip,
+				      flags))
+			goto partial;
+	}
+	if (!trace_seq_printf(s, "\n"))
+		goto partial;
+
+	return 0;
+
+ partial:
+	return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int
+trace_fn_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct ftrace_entry *field;
+
+	trace_assign_type(field, entry);
+
+	if (trace_seq_printf(s, "%x %x\n",
+			     field->ip,
+			     field->parent_ip))
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return 0;
+}
+
+static int
+trace_fn_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct ftrace_entry *field;
+
+	trace_assign_type(field, entry);
+
+	SEQ_PUT_HEX_FIELD_RET(s, field->ip);
+	SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
+
+	return 0;
+}
+
+static int
+trace_fn_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct ftrace_entry *field;
+
+	trace_assign_type(field, entry);
+
+	SEQ_PUT_FIELD_RET(s, field->ip);
+	SEQ_PUT_FIELD_RET(s, field->parent_ip);
+
+	return 0;
+}
+
+static struct trace_event trace_fn_event = {
+	.type	 	= TRACE_FN,
+	.trace		= trace_fn_trace,
+	.latency_trace	= trace_fn_latency,
+	.raw		= trace_fn_raw,
+	.hex		= trace_fn_hex,
+	.binary		= trace_fn_bin,
+};
+
+/* TRACE_CTX an TRACE_WAKE */
+static int
+trace_ctxwake_print(struct trace_seq *s, struct trace_entry *entry, int flags,
+		    char *delim)
+{
+	struct ctx_switch_entry *field;
+	char *comm;
+	int S, T;
+
+	trace_assign_type(field, entry);
+
+	T = task_state_char(field->next_state);
+	S = task_state_char(field->prev_state);
+	comm = trace_find_cmdline(field->next_pid);
+	if (trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
+			     field->prev_pid,
+			     field->prev_prio,
+			     S, delim,
+			     field->next_cpu,
+			     field->next_pid,
+			     field->next_prio,
+			     T, comm))
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return 0;
+}
+
+static int
+trace_ctx_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	return trace_ctxwake_print(s, entry, flags, "==>");
+}
+
+static int
+trace_wake_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	return trace_ctxwake_print(s, entry, flags, "  +");
+}
+
+static int
+trace_ctxwake_raw(struct trace_seq *s, struct trace_entry *entry, int flags,
+		  char S)
+{
+	struct ctx_switch_entry *field;
+	int T;
+
+	trace_assign_type(field, entry);
+
+	if (!S)
+		task_state_char(field->prev_state);
+	T = task_state_char(field->next_state);
+	if (trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
+			     field->prev_pid,
+			     field->prev_prio,
+			     S,
+			     field->next_cpu,
+			     field->next_pid,
+			     field->next_prio,
+			     T))
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return 0;
+}
+
+static int
+trace_ctx_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	return trace_ctxwake_raw(s, entry, flags, 0);
+}
+
+static int
+trace_wake_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	return trace_ctxwake_raw(s, entry, flags, '+');
+}
+
+
+static int
+trace_ctxwake_hex(struct trace_seq *s, struct trace_entry *entry, int flags,
+		  char S)
+{
+	struct ctx_switch_entry *field;
+	int T;
+
+	trace_assign_type(field, entry);
+
+	if (!S)
+		task_state_char(field->prev_state);
+	T = task_state_char(field->next_state);
+
+	SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
+	SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
+	SEQ_PUT_HEX_FIELD_RET(s, S);
+	SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
+	SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
+	SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
+	SEQ_PUT_HEX_FIELD_RET(s, T);
+
+	return 0;
+}
+
+static int
+trace_ctx_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	return trace_ctxwake_hex(s, entry, flags, 0);
+}
+
+static int
+trace_wake_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	return trace_ctxwake_hex(s, entry, flags, '+');
+}
+
+static int
+trace_ctxwake_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct ctx_switch_entry *field;
+
+	trace_assign_type(field, entry);
+
+	SEQ_PUT_FIELD_RET(s, field->prev_pid);
+	SEQ_PUT_FIELD_RET(s, field->prev_prio);
+	SEQ_PUT_FIELD_RET(s, field->prev_state);
+	SEQ_PUT_FIELD_RET(s, field->next_pid);
+	SEQ_PUT_FIELD_RET(s, field->next_prio);
+	SEQ_PUT_FIELD_RET(s, field->next_state);
+
+	return 0;
+}
+
+static struct trace_event trace_ctx_event = {
+	.type	 	= TRACE_CTX,
+	.trace		= trace_ctx_print,
+	.latency_trace	= trace_ctx_print,
+	.raw		= trace_ctx_raw,
+	.hex		= trace_ctx_hex,
+	.binary		= trace_ctxwake_bin,
+};
+
+static struct trace_event trace_wake_event = {
+	.type	 	= TRACE_WAKE,
+	.trace		= trace_wake_print,
+	.latency_trace	= trace_wake_print,
+	.raw		= trace_wake_raw,
+	.hex		= trace_wake_hex,
+	.binary		= trace_ctxwake_bin,
+};
+
+/* TRACE_SPECIAL */
+static int
+trace_special_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct special_entry *field;
+
+	trace_assign_type(field, entry);
+
+	if (trace_seq_printf(s, "# %ld %ld %ld\n",
+			     field->arg1,
+			     field->arg2,
+			     field->arg3))
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return 0;
+}
+
+static int
+trace_special_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct special_entry *field;
+
+	trace_assign_type(field, entry);
+
+	SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
+	SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
+	SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
+
+	return 0;
+}
+
+static int
+trace_special_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct special_entry *field;
+
+	trace_assign_type(field, entry);
+
+	SEQ_PUT_FIELD_RET(s, field->arg1);
+	SEQ_PUT_FIELD_RET(s, field->arg2);
+	SEQ_PUT_FIELD_RET(s, field->arg3);
+
+	return 0;
+}
+
+static struct trace_event trace_special_event = {
+	.type	 	= TRACE_SPECIAL,
+	.trace		= trace_special_print,
+	.latency_trace	= trace_special_print,
+	.raw		= trace_special_print,
+	.hex		= trace_special_hex,
+	.binary		= trace_special_bin,
+};
+
+/* TRACE_STACK */
+
+static int
+trace_stack_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct stack_entry *field;
+	int i;
+
+	trace_assign_type(field, entry);
+
+	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+		if (i) {
+			if (trace_seq_puts(s, " <= "))
+				goto partial;
+
+			if (seq_print_ip_sym(s, field->caller[i], flags))
+				goto partial;
+		}
+		if (trace_seq_puts(s, "\n"))
+			goto partial;
+	}
+
+	return 0;
+
+ partial:
+	return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static struct trace_event trace_stack_event = {
+	.type	 	= TRACE_STACK,
+	.trace		= trace_stack_print,
+	.latency_trace	= trace_stack_print,
+	.raw		= trace_special_print,
+	.hex		= trace_special_hex,
+	.binary		= trace_special_bin,
+};
+
+/* TRACE_USER_STACK */
+static int
+trace_user_stack_print(struct trace_seq *s, struct trace_entry *entry,
+		       int flags)
+{
+	struct userstack_entry *field;
+
+	trace_assign_type(field, entry);
+
+	if (seq_print_userip_objs(field, s, flags))
+		goto partial;
+
+	if (trace_seq_putc(s, '\n'))
+		goto partial;
+
+	return 0;
+
+ partial:
+	return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static struct trace_event trace_user_stack_event = {
+	.type	 	= TRACE_USER_STACK,
+	.trace		= trace_user_stack_print,
+	.latency_trace	= trace_user_stack_print,
+	.raw		= trace_special_print,
+	.hex		= trace_special_hex,
+	.binary		= trace_special_bin,
+};
+
+/* TRACE_PRINT */
+static int
+trace_print_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct print_entry *field;
+
+	trace_assign_type(field, entry);
+
+	if (seq_print_ip_sym(s, field->ip, flags))
+		goto partial;
+
+	if (trace_seq_printf(s, ": %s", field->buf))
+		goto partial;
+
+	return 0;
+
+ partial:
+	return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int
+trace_print_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+	struct print_entry *field;
+
+	trace_assign_type(field, entry);
+
+	if (seq_print_ip_sym(s, field->ip, flags))
+		goto partial;
+
+	if (trace_seq_printf(s, "# %lx %s", field->ip, field->buf))
+		goto partial;
+
+	return 0;
+
+ partial:
+	return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static struct trace_event trace_print_event = {
+	.type	 	= TRACE_PRINT,
+	.trace		= trace_print_print,
+	.latency_trace	= trace_print_print,
+	.raw		= trace_print_raw,
+	.hex		= trace_nop_print,
+	.binary		= trace_nop_print,
+};
+
+static struct trace_event *events[] __initdata = {
+	&trace_fn_event,
+	&trace_ctx_event,
+	&trace_wake_event,
+	&trace_special_event,
+	&trace_stack_event,
+	&trace_user_stack_event,
+	&trace_print_event,
+	NULL
+};
+
+__init static int init_events(void)
+{
+	struct trace_event *event;
+	int i, ret;
+
+	for (i = 0; events[i]; i++) {
+		event = events[i];
+
+		ret = register_ftrace_event(event);
+		if (!ret) {
+			printk(KERN_WARNING "event %d failed to register\n",
+			       event->type);
+			WARN_ON_ONCE(1);
+		}
+	}
+
+	return 0;
+}
+device_initcall(init_events);
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index 1fcc76e..ecab4ea 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -36,8 +36,24 @@ struct trace_event *ftrace_find_event(int type);
 int register_ftrace_event(struct trace_event *event);
 int unregister_ftrace_event(struct trace_event *event);
 
+int
+trace_nop_print(struct trace_seq *s, struct trace_entry *entry, int flags);
+
 #define MAX_MEMHEX_BYTES	8
 #define HEX_CHARS		(MAX_MEMHEX_BYTES*2 + 1)
 
+#define SEQ_PUT_FIELD_RET(s, x)				\
+do {							\
+	if (!trace_seq_putmem(s, &(x), sizeof(x)))	\
+		return 0;				\
+} while (0)
+
+#define SEQ_PUT_HEX_FIELD_RET(s, x)			\
+do {							\
+	BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES);	\
+	if (!trace_seq_putmem_hex(s, &(x), sizeof(x)))	\
+		return 0;				\
+} while (0)
+
 #endif
 
-- 
1.5.6.5

-- 

Re: [PATCH 0/3] ftrace: updates for tip

[Frederic Weisbecker]

Steven Rostedt wrote:
> This series restructures the output functions of trace.c.
> 
> Events are now registered and maintaining an event output is
> simplified by keeping the output close together.
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: tip/devel
> 
> 
> Steven Rostedt (3):
>       ftrace: remove obsolete print continue functionality
>       ftrace: set up trace event hash infrastructure
>       ftrace: change trace.c to use registered events
> 

Which does mean that a tracer will now be able to build as a module?
That's all good news!

I'm testing a bit these patches...

Re: [PATCH 0/3] ftrace: updates for tip

[Frederic Weisbecker]

Steven Rostedt wrote:
> This series restructures the output functions of trace.c.
> 
> Events are now registered and maintaining an event output is
> simplified by keeping the output close together.
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: tip/devel

BTW it seems to be more likely on devel than tip/devel ...

Re: [PATCH 0/3] ftrace: updates for tip

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> This series restructures the output functions of trace.c.
> 
> Events are now registered and maintaining an event output is
> simplified by keeping the output close together.
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: tip/devel
> 
> 
> Steven Rostedt (3):
>       ftrace: remove obsolete print continue functionality
>       ftrace: set up trace event hash infrastructure
>       ftrace: change trace.c to use registered events

pulled, thanks Steve!

	Ingo

[PATCH 0/3] ftrace: updates for tip

[Steven Rostedt]

Ingo,

The first patch here is to disable the branch tracer on ALPHA.
There has been several reports that the branch tracer breaks the
compile on ALPHA. Alpha uses ifs extern inlines, and the injecting
of static elements breaks the build.

The next patch fixes the selecting of a tracer for bootup.
Now you can select the default tracer from the kernel command line.

i.e.

  ftrace=function

Will start the function tracer as soon as it is registered.

Now that we have the kernel command line tracer selection working
we can use it for he boot "initcall" tracer. Instead of having the
initcall tracer disable selftests, it now needs to be selected
in the kernel command line as the default tracer to be implemented.
This means we can keep both selftest and boot initcall tracer configured
at the same time.

  ftrace=initcall

Will now enable the boot initcall tracer. No need to recompile.

-- Steve


The following patches are in:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git

    branch: tip/devel


Steven Rostedt (3):
      trace: disable branch tracer on alpha
      trace: fix default boot up tracer
      trace: let boot trace be chosen by command line

----
 kernel/trace/Kconfig      |    9 +++---
 kernel/trace/trace.c      |   65 ++++++++++++++++++++++++++++++++++++++-------
 kernel/trace/trace_boot.c |   11 +++++---
 3 files changed, 67 insertions(+), 18 deletions(-)
-- 

[PATCH 0/3] ftrace: updates for tip

[Steven Rostedt]

Ingo,

Arnaldo was nice enough to do something that was on my todo list
for quite some time.

I also included the change you asked for.

The following patches are in:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git

    branch: tip/devel


Arnaldo Carvalho de Melo (2):
      trace_branch: Remove unused function
      trace: Remove unused trace_array_cpu parameter

Steven Rostedt (1):
      trace: code style clean up

----
 block/blktrace.c                  |    2 +-
 kernel/trace/trace.c              |   76 ++++++++++++++++---------------------
 kernel/trace/trace.h              |    4 --
 kernel/trace/trace_branch.c       |   17 --------
 kernel/trace/trace_functions.c    |    8 ++--
 kernel/trace/trace_irqsoff.c      |   10 ++--
 kernel/trace/trace_sched_switch.c |    4 +-
 kernel/trace/trace_sched_wakeup.c |   12 ++---
 8 files changed, 50 insertions(+), 83 deletions(-)
-- 

Re: [PATCH 0/3] ftrace: updates for tip

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> Ingo,
> 
> Arnaldo was nice enough to do something that was on my todo list
> for quite some time.
> 
> I also included the change you asked for.
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: tip/devel
> 
> 
> Arnaldo Carvalho de Melo (2):
>       trace_branch: Remove unused function
>       trace: Remove unused trace_array_cpu parameter
> 
> Steven Rostedt (1):
>       trace: code style clean up
> 
> ----
>  block/blktrace.c                  |    2 +-
>  kernel/trace/trace.c              |   76 ++++++++++++++++---------------------
>  kernel/trace/trace.h              |    4 --
>  kernel/trace/trace_branch.c       |   17 --------
>  kernel/trace/trace_functions.c    |    8 ++--
>  kernel/trace/trace_irqsoff.c      |   10 ++--
>  kernel/trace/trace_sched_switch.c |    4 +-
>  kernel/trace/trace_sched_wakeup.c |   12 ++---
>  8 files changed, 50 insertions(+), 83 deletions(-)

Applied to tip:tracing/ftrace, thanks guys!

	Ingo