Commit Graph

1248 Commits

Author SHA1 Message Date
Steven Rostedt f42c85e74f tracing/events: move the ftrace event tracing code to core
This patch moves the ftrace creation into include/trace/ftrace.h and
simplifies the work of developers in adding new tracepoints.
Just the act of creating the trace points in include/trace and including
define_trace.h will create the events in the debugfs/tracing/events
directory.

This patch removes the need of include/trace/trace_events.h

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:57:59 -04:00
Steven Rostedt a8d154b009 tracing: create automated trace defines
This patch lowers the number of places a developer must modify to add
new tracepoints. The current method to add a new tracepoint
into an existing system is to write the trace point macro in the
trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or
DECLARE_TRACE, then they must add the same named item into the C file
with the macro DEFINE_TRACE(name) and then add the trace point.

This change cuts out the needing to add the DEFINE_TRACE(name).
Every file that uses the tracepoint must still include the trace/<type>.h
file, but the one C file must also add a define before the including
of that file.

 #define CREATE_TRACE_POINTS
 #include <trace/mytrace.h>

This will cause the trace/mytrace.h file to also produce the C code
necessary to implement the trace point.

Note, if more than one trace/<type>.h is used to create the C code
it is best to list them all together.

 #define CREATE_TRACE_POINTS
 #include <trace/foo.h>
 #include <trace/bar.h>
 #include <trace/fido.h>

Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with
the cleaner solution of the define above the includes over my first
design to have the C code include a "special" header.

This patch converts sched, irq and lockdep and skb to use this new
method.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 12:57:28 -04:00
Steven Rostedt ea20d9293c tracing: consolidate trace and trace_event headers
Impact: clean up

Neil Horman (et. al.) criticized the way the trace events were broken up
into two files. The reason for that was that ftrace needed to separate out
the declarations from where the #include <linux/tracepoint.h> was used.
It then dawned on me that the tracepoint.h header only needs to define the
TRACE_EVENT macro if it is not already defined.

The solution is simply to test if TRACE_EVENT is defined, and if it is not
then the linux/tracepoint.h header can define it. This change consolidates
all the <traces>.h and <traces>_event_types.h into the <traces>.h file.

Reported-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Theodore Tso <tytso@mit.edu>
Reported-by: Jiaying Zhang <jiayingz@google.com>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 09:43:40 -04:00
Zhaolei fc182a4330 tracing, kmemtrace: Make kmem tracepoints use TRACE_EVENT macro
TRACE_EVENT is a more generic way to define tracepoints.
Doing so adds these new capabilities to this tracepoint:

  - zero-copy and per-cpu splice() tracing
  - binary tracing without printf overhead
  - structured logging records exposed under /debug/tracing/events
  - trace events embedded in function tracer output and other plugins
  - user-defined, per tracepoint filter expressions

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49DEE6DA.80600@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-12 15:22:56 +02:00
Zhaolei 02af61bb50 tracing, kmemtrace: Separate include/trace/kmemtrace.h to kmemtrace part and tracepoint part
Impact: refactor code for future changes

Current kmemtrace.h is used both as header file of kmemtrace and kmem's
tracepoints definition.

Tracepoints' definition file may be used by other code, and should only have
definition of tracepoint.

We can separate include/trace/kmemtrace.h into 2 files:

  include/linux/kmemtrace.h: header file for kmemtrace
  include/trace/kmem.h:      definition of kmem tracepoints

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49DEE68A.5040902@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-12 15:22:55 +02:00
Zhaolei 5cb3d1d9d3 tracing, net, skb tracepoint: make skb tracepoint use the TRACE_EVENT() macro
TRACE_EVENT is a more generic way to define a tracepoint.
Doing so adds these new capabilities to this tracepoint:

  - zero-copy and per-cpu splice() tracing
  - binary tracing without printf overhead
  - structured logging records exposed under /debug/tracing/events
  - trace events embedded in function tracer output and other plugins
  - user-defined, per tracepoint filter expressions

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "Steven Rostedt ;" <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49DD90D2.5020604@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-10 12:57:55 +02:00
Frederic Weisbecker 2062501ae6 tracing/lockdep: report the time waited for a lock
While trying to optimize the new lock on reiserfs to replace
the bkl, I find the lock tracing very useful though it lacks
something important for performance (and latency) instrumentation:
the time a task waits for a lock.

That's what this patch implements:

  bash-4816  [000]   202.652815: lock_contended: lock_contended: &sb->s_type->i_mutex_key
  bash-4816  [000]   202.652819: lock_acquired: &rq->lock (0.000 us)
 <...>-4787  [000]   202.652825: lock_acquired: &rq->lock (0.000 us)
 <...>-4787  [000]   202.652829: lock_acquired: &rq->lock (0.000 us)
  bash-4816  [000]   202.652833: lock_acquired: &sb->s_type->i_mutex_key (16.005 us)

As shown above, the "lock acquired" field is followed by the time
it has been waiting for the lock. Usually, a lock contended entry
is followed by a near lock_acquired entry with a non-zero time waited.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1238975373-15739-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-10 12:50:56 +02:00
Frederic Weisbecker 47788c58e6 tracing/syscalls: use a dedicated file header
Impact: fix build warnings and possibe compat misbehavior on IA64

Building a kernel on ia64 might trigger these ugly build warnings:

CC      arch/ia64/ia32/sys_ia32.o
In file included from arch/ia64/ia32/sys_ia32.c:55:
arch/ia64/ia32/ia32priv.h:290:1: warning: "elf_check_arch" redefined
In file included from include/linux/elf.h:7,
                 from include/linux/module.h:14,
                 from include/linux/ftrace.h:8,
                 from include/linux/syscalls.h:68,
                 from arch/ia64/ia32/sys_ia32.c:18:
arch/ia64/include/asm/elf.h:19:1: warning: this is the location of the previous definition
[...]

sys_ia32.c includes linux/syscalls.h which in turn includes linux/ftrace.h
to import the syscalls tracing prototypes.

But including ftrace.h can pull too much things for a low level file,
especially on ia64 where the ia32 private headers conflict with higher
level headers.

Now we isolate the syscall tracing headers in their own lightweight file.

Reported-by: Tony Luck <tony.luck@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Baron <jbaron@redhat.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Michael Rubin <mrubin@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Michael Davidson <md@google.com>
LKML-Reference: <20090408184058.GB6017@nowhere>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-09 05:43:32 +02:00
Eduard - Gabriel Munteanu ca2b84cb3c kmemtrace: use tracepoints
kmemtrace now uses tracepoints instead of markers. We no longer need to
use format specifiers to pass arguments.

Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
[ folded: Use the new TP_PROTO and TP_ARGS to fix the build.     ]
[ folded: fix build when CONFIG_KMEMTRACE is disabled.           ]
[ folded: define tracepoints when CONFIG_TRACEPOINTS is enabled. ]
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <ae61c0f37156db8ec8dc0d5778018edde60a92e3.1237813499.git.eduard.munteanu@linux360.ro>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-03 12:23:06 +02:00
Stephen Rothwell 645dae969c tracing, net: fix net tree and tracing tree merge interaction
Today's linux-next build (powerpc ppc64_defconfig) failed like this:

 In file included from net/core/skbuff.c:69:
 include/trace/skb.h:4: error: expected ')' before '(' token
 include/trace/skb.h:4: error: expected ')' before '(' token
 [...]

Caused by commit 2939b0469d ("tracing:
replace TP<var> with TP_<var>") from the tracing tree interacting with
commit 4893d39e86 ("Network Drop Monitor:
Add trace declaration for skb frees") from the net tree.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-02 00:50:30 +02:00
Ingo Molnar 8302294f43 Merge branch 'tracing/core-v2' into tracing-for-linus
Conflicts:
	include/linux/slub_def.h
	lib/Kconfig.debug
	mm/slob.c
	mm/slub.c
2009-04-02 00:49:02 +02:00
Josh Stone 5393f3162d net: Add dependent headers to trace/skb.h
The tracing header needs to include definitions for the macros used and
the types referenced.  This lets automated tracing tools like SystemTap
make use of the tracepoint without any specific knowledge of its
meaning (leaving that to the user).

Signed-off-by: Josh Stone <jistone@redhat.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-24 14:24:10 -07:00
Neil Horman 4893d39e86 Network Drop Monitor: Add trace declaration for skb frees
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>

 include/trace/skb.h   |    8 ++++++++
 net/core/Makefile     |    2 ++
 net/core/net-traces.c |   29 +++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+)
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-13 12:09:27 -07:00
Jason Baron 39842323ce tracing: tracepoints for softirq entry/exit - tracepoints
Introduce softirq entry/exit tracepoints. These are useful for
augmenting existing tracers, and to figure out softirq frequencies and
timings.

[
  s/irq_softirq_/softirq_/ for trace point names and
  Fixed printf format in TRACE_FORMAT macro
   - Steven Rostedt
]

LKML-Reference: <20090312183603.GC3352@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-12 21:20:58 -04:00
Steven Rostedt 30a8fecc2d tracing: flip the TP_printk and TP_fast_assign in the TRACE_EVENT macro
Impact: clean up

In trying to stay consistant with the C style format in the TRACE_EVENT
macro, it makes more sense to do the printk after the assigning of
the variables.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 12:41:38 -04:00
Steven Rostedt 157587d7ac tracing: remove obsolete TRACE_EVENT_FORMAT macro
Impact: clean up

The TRACE_EVENT_FORMAT macro is no longer used by trace points
and only the DECLARE_TRACE, TRACE_FORMAT or TRACE_EVENT macros should
be used by them. Although the TRACE_EVENT_FORMAT macro is still used
by the internal tracing utility, it should not be used in core
kernel code.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:12 -04:00
Steven Rostedt d6e2ca4c05 tracing: convert irq trace points to new macros
Impact: enhancement

Converted the two irq trace point macros. The entry macro copies
the name of the irq handler, thus it is better to simply use the
TRACE_FORMAT macro which uses the trace_printk.

The return of the handler does not need to record the name, thus
the faster C style handler is more approriate.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:11 -04:00
Steven Rostedt 12b5fdb8bb tracing: convert the sched trace points to the TRACE_EVENT macros
Impact: enhancement

This patch converts the rest of the sched trace points to use the new
more powerful TRACE_EVENT macro.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:09 -04:00
Steven Rostedt da4d03020c tracing: new format for specialized trace points
Impact: clean up and enhancement

The TRACE_EVENT_FORMAT macro looks quite ugly and is limited in its
ability to save data as well as to print the record out. Working with
Ingo Molnar, we came up with a new format that is much more pleasing to
the eye of C developers. This new macro is more C style than the old
macro, and is more obvious to what it does.

Here's the example. The only updated macro in this patch is the
sched_switch trace point.

The old method looked like this:

 TRACE_EVENT_FORMAT(sched_switch,
        TP_PROTO(struct rq *rq, struct task_struct *prev,
                struct task_struct *next),
        TP_ARGS(rq, prev, next),
        TP_FMT("task %s:%d ==> %s:%d",
              prev->comm, prev->pid, next->comm, next->pid),
        TRACE_STRUCT(
                TRACE_FIELD(pid_t, prev_pid, prev->pid)
                TRACE_FIELD(int, prev_prio, prev->prio)
                TRACE_FIELD_SPECIAL(char next_comm[TASK_COMM_LEN],
                                    next_comm,
                                    TP_CMD(memcpy(TRACE_ENTRY->next_comm,
                                                 next->comm,
                                                 TASK_COMM_LEN)))
                TRACE_FIELD(pid_t, next_pid, next->pid)
                TRACE_FIELD(int, next_prio, next->prio)
        ),
        TP_RAW_FMT("prev %d:%d ==> next %s:%d:%d")
        );

The above method is hard to read and requires two format fields.

The new method:

 /*
  * Tracepoint for task switches, performed by the scheduler:
  *
  * (NOTE: the 'rq' argument is not used by generic trace events,
  *        but used by the latency tracer plugin. )
  */
 TRACE_EVENT(sched_switch,

	TP_PROTO(struct rq *rq, struct task_struct *prev,
		 struct task_struct *next),

	TP_ARGS(rq, prev, next),

	TP_STRUCT__entry(
		__array(	char,	prev_comm,	TASK_COMM_LEN	)
		__field(	pid_t,	prev_pid			)
		__field(	int,	prev_prio			)
		__array(	char,	next_comm,	TASK_COMM_LEN	)
		__field(	pid_t,	next_pid			)
		__field(	int,	next_prio			)
	),

	TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
		__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
		__entry->next_comm, __entry->next_pid, __entry->next_prio),

	TP_fast_assign(
		memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
		__entry->prev_pid	= prev->pid;
		__entry->prev_prio	= prev->prio;
		memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
		__entry->next_pid	= next->pid;
		__entry->next_prio	= next->prio;
	)
 );

This macro is called TRACE_EVENT, it is broken up into 5 parts:

 TP_PROTO:        the proto type of the trace point
 TP_ARGS:         the arguments of the trace point
 TP_STRUCT_entry: the structure layout of the entry in the ring buffer
 TP_printk:       the printk format
 TP_fast_assign:  the method used to write the entry into the ring buffer

The structure is the definition of how the event will be saved in the
ring buffer. The printk is used by the internal tracing in case of
an oops, and the kernel needs to print out the format of the record
to the console. This the TP_printk gives a means to show the records
in a human readable format. It is also used to print out the data
from the trace file.

The TP_fast_assign is executed directly. It is basically like a C function,
where the __entry is the handle to the record.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:07 -04:00
Steven Rostedt 2939b0469d tracing: replace TP<var> with TP_<var>
Impact: clean up

The macros TPPROTO, TPARGS, TPFMT, TPRAWFMT, and TPCMD all look a bit
ugly. This patch adds an underscore to their names.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:04 -04:00
Ingo Molnar af438c0f11 tracing, power-trace: make it build even if the power-tracer is turned off
Impact: build fix

The 'struct power_trace' definition is needed (for the event tracer) even if
the power-tracer plugin is turned off in the .config.

Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <20090306104106.GF31042@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 12:47:08 +01:00
Peter Zijlstra efed792d67 tracing: add lockdep tracepoints for lock acquire/release
Augment the traces with lock names when lockdep is available:

 1)               |  down_read_trylock() {
 1)               |    _spin_lock_irqsave() {
 1)               |      /* lock_acquire: &sem->wait_lock */
 1)   4.201 us    |    }
 1)               |    _spin_unlock_irqrestore() {
 1)               |      /* lock_release: &sem->wait_lock */
 1)   3.523 us    |    }
 1)               |  /* lock_acquire: try read &mm->mmap_sem */
 1) + 13.386 us   |  }
 1)   1.635 us    |  find_vma();
 1)               |  handle_mm_fault() {
 1)               |    __do_fault() {
 1)               |      filemap_fault() {
 1)               |        find_lock_page() {
 1)               |          find_get_page() {
 1)               |            /* lock_acquire: read rcu_read_lock */
 1)               |            /* lock_release: rcu_read_lock */
 1)   5.697 us    |          }
 1)   8.158 us    |        }
 1) + 11.079 us   |      }
 1)               |      _spin_lock() {
 1)               |        /* lock_acquire: __pte_lockptr(page) */
 1)   3.949 us    |      }
 1)   1.460 us    |      page_add_file_rmap();
 1)               |      _spin_unlock() {
 1)               |        /* lock_release: __pte_lockptr(page) */
 1)   3.115 us    |      }
 1)               |      unlock_page() {
 1)   1.421 us    |        page_waitqueue();
 1)   1.220 us    |        __wake_up_bit();
 1)   6.519 us    |      }
 1) + 34.328 us   |    }
 1) + 37.452 us   |  }
 1)               |  up_read() {
 1)               |  /* lock_release: &mm->mmap_sem */
 1)               |    _spin_lock_irqsave() {
 1)               |      /* lock_acquire: &sem->wait_lock */
 1)   3.865 us    |    }
 1)               |    _spin_unlock_irqrestore() {
 1)               |      /* lock_release: &sem->wait_lock */
 1)   8.562 us    |    }
 1) + 17.370 us   |  }

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: =?ISO-8859-1?Q?T=F6r=F6k?= Edwin <edwintorok@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1236166375.5330.7209.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04 18:49:58 +01:00
Steven Rostedt d20e3b0384 tracing: add TRACE_FIELD_SPECIAL to record complex entries
Tom Zanussi pointed out that the simple TRACE_FIELD was not enough to
record trace data that required memcpy. This patch addresses this issue
by adding a TRACE_FIELD_SPECIAL. The format is similar to TRACE_FIELD
but looks like so:

  TRACE_FIELD_SPECIAL(type_item, item, cmd)

What TRACE_FIELD gave was:

  TRACE_FIELD(type, item, assign)

The TRACE_FIELD would be used in declaring a structure:

  struct {
	type	item;
  };

And later assign it via:

  entry->item = assign;

What TRACE_FIELD_SPECIAL gives us is:

In the declaration of the structure:

  struct {
	type_item;
  };

And the assignment:

  cmd;

This change log will explain the one example used in the patch:

 TRACE_EVENT_FORMAT(sched_switch,
	TPPROTO(struct rq *rq, struct task_struct *prev,
		struct task_struct *next),
	TPARGS(rq, prev, next),
	TPFMT("task %s:%d ==> %s:%d",
	      prev->comm, prev->pid, next->comm, next->pid),
	TRACE_STRUCT(
		TRACE_FIELD(pid_t, prev_pid, prev->pid)
		TRACE_FIELD(int, prev_prio, prev->prio)
		TRACE_FIELD_SPECIAL(char next_comm[TASK_COMM_LEN],
				    next_comm,
				    TPCMD(memcpy(TRACE_ENTRY->next_comm,
						 next->comm,
						 TASK_COMM_LEN)))
		TRACE_FIELD(pid_t, next_pid, next->pid)
		TRACE_FIELD(int, next_prio, next->prio)
	),
	TPRAWFMT("prev %d:%d ==> next %s:%d:%d")
	);

 The struct will be create as:

  struct {
	pid_t		prev_pid;
	int		prev_prio;
	char next_comm[TASK_COMM_LEN];
	pid_t		next_pid;
	int		next_prio;
  };

Note the TRACE_ENTRY in the cmd part of TRACE_SPECIAL. TRACE_ENTRY will
be set by the tracer to point to the structure inside the trace buffer.

  entry->prev_pid	= prev->pid;
  entry->prev_prio	= prev->prio;
  memcpy(entry->next_comm, next->comm, TASK_COMM_LEN);
  entry->next_pid	= next->pid;
  entry->next_prio	= next->prio

Reported-by: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-02 10:53:15 -05:00
Steven Rostedt f2034f1e1a tracing: create the C style tracing for the irq subsystem
This patch utilizes the TRACE_EVENT_FORMAT macro to enable the C style
faster tracing for the irq subsystem trace points.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-28 04:04:14 -05:00
Steven Rostedt 629928041c tracing: create the C style tracing for the sched subsystem
This patch utilizes the TRACE_EVENT_FORMAT macro to enable the C style
faster tracing for the sched subsystem trace points.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-28 04:04:13 -05:00
Steven Rostedt 3d7ba938da tracing: add subsystem sched for sched events
Add the TRACE_SYSTEM sched for the sched events.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-28 03:06:31 -05:00
Steven Rostedt 0ec2ef1505 tracing: add subsystem irq for irq events
Add the TRACE_SYSTEM irq for the irq events.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-28 03:06:13 -05:00
Steven Rostedt eb594e45f6 tracing: move trace point formats to files in include/trace directory
Impact: clean up

To further facilitate the ease of adding trace points for developers, this
patch creates include/trace/trace_events.h and
include/trace/trace_event_types.h.

The former file will hold the trace/<type>.h files and the latter will hold
the trace/<type>_event_types.h files.

To create new tracepoints and to have them automatically
appear in the event tracer, a developer makes the trace/<type>.h file
which includes <linux/tracepoint.h> and the trace/<type>_event_types.h file.

The trace/<type>_event_types.h file will hold the TRACE_FORMAT
macros.

Then add the trace/<type>.h file to trace/trace_events.h,
and add the trace/<type>_event_types.h to the trace_event_types.h file.

No need to modify files elsewhere.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-28 02:58:50 -05:00
Jason Baron af39241b90 tracing, genirq: add irq enter and exit trace events
Impact: add new tracepoints

Add them to the generic IRQ code, that way every architecture
gets these new tracepoints, not just x86.

Using Steve's new 'TRACE_FORMAT', I can get function graph
trace as follows using the original two IRQ tracepoints:

 3)               |    handle_IRQ_event() {
 3)               |    /* (irq_handler_entry) irq=28 handler=eth0 */
 3)               |    e1000_intr_msi() {
 3)   2.460 us    |      __napi_schedule();
 3)   9.416 us    |    }
 3)               |    /* (irq_handler_exit) irq=28 handler=eth0 return=handled */
 3) + 22.935 us   |  }

Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-26 18:43:50 +01:00
Steven Rostedt eef62a6826 tracing: rename DEFINE_TRACE_FMT to just TRACE_FORMAT
There's been a bit confusion to whether DEFINE/DECLARE_TRACE_FMT should
be a DEFINE or a DECLARE. Ingo Molnar suggested simply calling it
TRACE_FORMAT.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-25 21:44:22 -05:00
Steven Rostedt f3fe8e4a38 tracing: add schedule events to event trace
This patch changes the trace/sched.h to use the DECLARE_TRACE_FMT
such that they are automatically registered with the event tracer.

And it also adds the tracing sched headers to kernel/trace/events.c

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-24 21:54:07 -05:00
Jason Baron b5f9fd0f8a tracing: convert c/p state power tracer to use tracepoints
Convert the c/p state "power" tracer to use tracepoints. Avoids a
function call when the tracer is disabled.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-13 09:06:18 -05:00
Frederic Weisbecker 1292211058 tracing/power: move the power trace headers to a dedicated file
Impact: cleanup

Move the power tracer headers to trace/power.h to keep ftrace.h and power bits
more easy to maintain as separated topics.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09 10:51:38 +01:00
Frederic Weisbecker e1d8aa9f1d tracing: add a new workqueue tracer
Impact: new tracer

The workqueue tracer provides some statistical informations
about each cpu workqueue thread such as the number of the
works inserted and executed since their creation. It can help
to evaluate the amount of work each of them have to perform.
For example it can help a developer to decide whether he should
choose a per cpu workqueue instead of a singlethreaded one.

It only traces statistical informations for now but it will probably later
provide event tracing too.

Such a tracer could help too, and be improved, to help rt priority sorted
workqueue development.

To have a snapshot of the workqueues state at any time, just do

cat /debugfs/tracing/trace_stat/workqueues

Ie:

  1    125        125       reiserfs/1
  1      0          0       scsi_tgtd/1
  1      0          0       aio/1
  1      0          0       ata/1
  1    114        114       kblockd/1
  1      0          0       kintegrityd/1
  1   2147       2147       events/1

  0      0          0       kpsmoused
  0    105        105       reiserfs/0
  0      0          0       scsi_tgtd/0
  0      0          0       aio/0
  0      0          0       ata_aux
  0      0          0       ata/0
  0      0          0       cqueue
  0      0          0       kacpi_notify
  0      0          0       kacpid
  0    149        149       kblockd/0
  0      0          0       kintegrityd/0
  0   1000       1000       khelper
  0   2270       2270       events/0

Changes in V2:

_ Drop the static array based on NR_CPU and dynamically allocate the stat array
  with num_possible_cpus() and other cpu mask facilities....
_ Trace workqueue insertion at a bit lower level (insert_work instead of queue_work) to handle
  even the workqueue barriers.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14 12:11:43 +01:00
Frederic Weisbecker 36994e58a4 tracing/kmemtrace: normalize the raw tracer event to the unified tracing API
Impact: new tracer plugin

This patch adapts kmemtrace raw events tracing to the unified tracing API.

To enable and use this tracer, just do the following:

 echo kmemtrace > /debugfs/tracing/current_tracer
 cat /debugfs/tracing/trace

You will have the following output:

 # tracer: kmemtrace
 #
 #
 # ALLOC  TYPE  REQ   GIVEN  FLAGS           POINTER         NODE    CALLER
 # FREE   |      |     |       |              |   |            |        |
 # |

type_id 1 call_site 18446744071565527833 ptr 18446612134395152256
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345164672 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345164912 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345165152 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 0 call_site 18446744071566144042 ptr 18446612134346191680 bytes_req 1304 bytes_alloc 1312 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584

That was to stay backward compatible with the format output produced in
inux/tracepoint.h.

This is the default ouput, but note that I tried something else.

If you change an option:

echo kmem_minimalistic > /debugfs/trace_options

and then cat /debugfs/trace, you will have the following output:

 # tracer: kmemtrace
 #
 #
 # ALLOC  TYPE  REQ   GIVEN  FLAGS           POINTER         NODE    CALLER
 # FREE   |      |     |       |              |   |            |        |
 # |

   -      C                            0xffff88007c088780          file_free_rcu
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   -      C                            0xffff88007cad6000          putname
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   +      K    240    240   000000d0   0xffff8800790dc780     -1   d_alloc
   -      C                            0xffff88007cad6000          putname
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   +      K    240    240   000000d0   0xffff8800790dc870     -1   d_alloc
   -      C                            0xffff88007cad6000          putname
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   +      K    240    240   000000d0   0xffff8800790dc960     -1   d_alloc
   +      K   1304   1312   000000d0   0xffff8800791d7340     -1   reiserfs_alloc_inode
   -      C                            0xffff88007cad6000          putname
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   -      C                            0xffff88007cad6000          putname
   +      K    992   1000   000000d0   0xffff880079045b58     -1   alloc_inode
   +      K    768   1024   000080d0   0xffff88007c096400     -1   alloc_pipe_info
   +      K    240    240   000000d0   0xffff8800790dca50     -1   d_alloc
   +      K    272    320   000080d0   0xffff88007c088780     -1   get_empty_filp
   +      K    272    320   000080d0   0xffff88007c088000     -1   get_empty_filp

Yeah I shall confess kmem_minimalistic should be: kmem_alternative.

Whatever, I find it more readable but this a personal opinion of course.
We can drop it if you want.

On the ALLOC/FREE column, + means an allocation and - a free.

On the type column, you have K = kmalloc, C = cache, P = page

I would like the flags to be GFP_* strings but that would not be easy to not
break the column with strings....

About the node...it seems to always be -1. I don't know why but that shouldn't
be difficult to find.

I moved linux/tracepoint.h to trace/tracepoint.h as well. I think that would
be more easy to find the tracer headers if they are all in their common
directory.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-30 09:36:13 +01:00
Peter Zijlstra 468a15bb4c sched, trace: update trace_sched_wakeup()
Impact: extend the wakeup tracepoint with the info whether the wakeup was real

Add the information needed to distinguish 'real' wakeups from 'false'
wakeups.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-25 13:10:21 +01:00
Ingo Molnar c71dd42db2 tracing: fix warnings in kernel/trace/trace_sched_switch.c
these warnings:

  kernel/trace/trace_sched_switch.c: In function ‘tracing_sched_register’:
  kernel/trace/trace_sched_switch.c:96: warning: passing argument 1 of ‘register_trace_sched_wakeup_new’ from incompatible pointer type
  kernel/trace/trace_sched_switch.c:112: warning: passing argument 1 of ‘unregister_trace_sched_wakeup_new’ from incompatible pointer type
  kernel/trace/trace_sched_switch.c: In function ‘tracing_sched_unregister’:
  kernel/trace/trace_sched_switch.c:121: warning: passing argument 1 of ‘unregister_trace_sched_wakeup_new’ from incompatible pointer type

Trigger because sched_wakeup_new tracepoints need the same trace
signature as sched_wakeup - which was changed recently.

Fix it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 01:05:38 +01:00
Ingo Molnar 9dfc3bc7d2 Merge branches 'tracing/fastboot', 'tracing/ftrace', 'tracing/function-graph-tracer' and 'tracing/hw-branch-tracing' into tracing/core 2008-12-16 12:03:38 +01:00
Peter Zijlstra cbc34ed1ac sched: fix tracepoints in scheduler
The trace point only caught one of many places where a task changes cpu,
put it in the right place to we get all of them.

Change the signature while we're at it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-12 12:08:26 +01:00
Frederic Weisbecker da485e0cb1 tracing/fastboot: include missing headers
For now include/trace/boot.h doesn't need to include necessary headers
for its functions and structures because the files that include it already
do it.

But boot.h could be needed as well for further uses on other files.
So, this patch adds the necessary headers for future purposes...

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-12 09:26:13 +01:00
Stephen Rothwell 8001530d5a tracing/fastboot: fix len of func buffer
Impact: fix possible stack overrun

This is a port of a patch included in the mainline (KSYM_SYMBOL_LEN fixes).
The current func len is not large enough to contain the max symbol len, the
right size must be KSYM_SYMBOL_LEN.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-12 09:26:12 +01:00
Ingo Molnar 0bfc24559d blktrace: port to tracepoints, update
Port to the new tracepoints API: split DEFINE_TRACE() and DECLARE_TRACE()
sites. Spread them out to the usage sites, as suggested by
Mathieu Desnoyers.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
2008-11-26 13:04:35 +01:00
Arnaldo Carvalho de Melo 5f3ea37c77 blktrace: port to tracepoints
This was a forward port of work done by Mathieu Desnoyers, I changed it to
encode the 'what' parameter on the tracepoint name, so that one can register
interest in specific events and not on classes of events to then check the
'what' parameter.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-26 12:13:34 +01:00
Mathieu Desnoyers 7e066fb870 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE()
Impact: API *CHANGE*. Must update all tracepoint users.

Add DEFINE_TRACE() to tracepoints to let them declare the tracepoint
structure in a single spot for all the kernel. It helps reducing memory
consumption, especially when declaring a lot of tracepoints, e.g. for
kmalloc tracing.

*API CHANGE WARNING*: now, DECLARE_TRACE() must be used in headers for
tracepoint declarations rather than DEFINE_TRACE(). This is the sane way
to do it. The name previously used was misleading.

Updates scheduler instrumentation to follow this API change.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-16 09:01:36 +01:00
Frederic Weisbecker 7423907283 tracing/fastboot: Use the ring-buffer timestamp for initcall entries
Impact: Split the boot tracer entries in two parts: call and return

Now that we are using the sched tracer from the boot tracer, we want
to use the same timestamp than the ring-buffer to have consistent time
captures between sched events and initcall events.

So we get rid of the old time capture by the boot tracer and split the
initcall events in two parts: call and return. This way we have the
ring buffer timestamp of both.

An example trace:

[   27.904149584] calling  net_ns_init+0x0/0x1c0 @ 1
[   27.904429624] initcall net_ns_init+0x0/0x1c0 returned 0 after 0 msecs
[   27.904575926] calling  reboot_init+0x0/0x20 @ 1
[   27.904655399] initcall reboot_init+0x0/0x20 returned 0 after 0 msecs
[   27.904800228] calling  sysctl_init+0x0/0x30 @ 1
[   27.905142914] initcall sysctl_init+0x0/0x30 returned 0 after 0 msecs
[   27.905287211] calling  ksysfs_init+0x0/0xb0 @ 1
 ##### CPU 0 buffer started ####
            init-1     [000]    27.905395:      1:120:R   + [001]    11:115:S
 ##### CPU 1 buffer started ####
          <idle>-0     [001]    27.905425:      0:140:R ==> [001]    11:115:R
            init-1     [000]    27.905426:      1:120:D ==> [000]     0:140:R
          <idle>-0     [000]    27.905431:      0:140:R   + [000]     4:115:S
          <idle>-0     [000]    27.905451:      0:140:R ==> [000]     4:115:R
     ksoftirqd/0-4     [000]    27.905456:      4:115:S ==> [000]     0:140:R
           udevd-11    [001]    27.905458:     11:115:R   + [001]    14:115:R
          <idle>-0     [000]    27.905459:      0:140:R   + [000]     4:115:S
          <idle>-0     [000]    27.905462:      0:140:R ==> [000]     4:115:R
           udevd-11    [001]    27.905462:     11:115:R ==> [001]    14:115:R
     ksoftirqd/0-4     [000]    27.905467:      4:115:S ==> [000]     0:140:R
          <idle>-0     [000]    27.905470:      0:140:R   + [000]     4:115:S
          <idle>-0     [000]    27.905473:      0:140:R ==> [000]     4:115:R
     ksoftirqd/0-4     [000]    27.905476:      4:115:S ==> [000]     0:140:R
          <idle>-0     [000]    27.905479:      0:140:R   + [000]     4:115:S
          <idle>-0     [000]    27.905482:      0:140:R ==> [000]     4:115:R
     ksoftirqd/0-4     [000]    27.905486:      4:115:S ==> [000]     0:140:R
           udevd-14    [001]    27.905499:     14:120:X ==> [001]    11:115:R
           udevd-11    [001]    27.905506:     11:115:R   + [000]     1:120:D
          <idle>-0     [000]    27.905515:      0:140:R ==> [000]     1:120:R
           udevd-11    [001]    27.905517:     11:115:S ==> [001]     0:140:R
[   27.905557107] initcall ksysfs_init+0x0/0xb0 returned 0 after 3906 msecs
[   27.905705736] calling  init_jiffies_clocksource+0x0/0x10 @ 1
[   27.905779239] initcall init_jiffies_clocksource+0x0/0x10 returned 0 after 0 msecs
[   27.906769814] calling  pm_init+0x0/0x30 @ 1
[   27.906853627] initcall pm_init+0x0/0x30 returned 0 after 0 msecs
[   27.906997803] calling  pm_disk_init+0x0/0x20 @ 1
[   27.907076946] initcall pm_disk_init+0x0/0x20 returned 0 after 0 msecs
[   27.907222556] calling  swsusp_header_init+0x0/0x30 @ 1
[   27.907294325] initcall swsusp_header_init+0x0/0x30 returned 0 after 0 msecs
[   27.907439620] calling  stop_machine_init+0x0/0x50 @ 1
            init-1     [000]    27.907485:      1:120:R   + [000]     2:115:S
            init-1     [000]    27.907490:      1:120:D ==> [000]     2:115:R
        kthreadd-2     [000]    27.907507:      2:115:R   + [001]    15:115:R
          <idle>-0     [001]    27.907517:      0:140:R ==> [001]    15:115:R
        kthreadd-2     [000]    27.907517:      2:115:D ==> [000]     0:140:R
          <idle>-0     [000]    27.907521:      0:140:R   + [000]     4:115:S
          <idle>-0     [000]    27.907524:      0:140:R ==> [000]     4:115:R
           udevd-15    [001]    27.907527:     15:115:D   + [000]     2:115:D
     ksoftirqd/0-4     [000]    27.907537:      4:115:S ==> [000]     2:115:R
           udevd-15    [001]    27.907537:     15:115:D ==> [001]     0:140:R
        kthreadd-2     [000]    27.907546:      2:115:R   + [000]     1:120:D
        kthreadd-2     [000]    27.907550:      2:115:S ==> [000]     1:120:R
            init-1     [000]    27.907584:      1:120:R   + [000]    15:  0:D
            init-1     [000]    27.907589:      1:120:R   + [000]     2:115:S
            init-1     [000]    27.907593:      1:120:D ==> [000]    15:  0:R
           udevd-15    [000]    27.907601:     15:  0:S ==> [000]     2:115:R
 ##### CPU 0 buffer started ####
        kthreadd-2     [000]    27.907616:      2:115:R   + [001]    16:115:R
 ##### CPU 1 buffer started ####
          <idle>-0     [001]    27.907620:      0:140:R ==> [001]    16:115:R
        kthreadd-2     [000]    27.907621:      2:115:D ==> [000]     0:140:R
           udevd-16    [001]    27.907625:     16:115:D   + [000]     2:115:D
          <idle>-0     [000]    27.907628:      0:140:R   + [000]     4:115:S
           udevd-16    [001]    27.907629:     16:115:D ==> [001]     0:140:R
          <idle>-0     [000]    27.907631:      0:140:R ==> [000]     4:115:R
     ksoftirqd/0-4     [000]    27.907636:      4:115:S ==> [000]     2:115:R
        kthreadd-2     [000]    27.907644:      2:115:R   + [000]     1:120:D
        kthreadd-2     [000]    27.907647:      2:115:S ==> [000]     1:120:R
            init-1     [000]    27.907657:      1:120:R   + [001]    16:  0:D
          <idle>-0     [001]    27.907666:      0:140:R ==> [001]    16:  0:R
[   27.907703862] initcall stop_machine_init+0x0/0x50 returned 0 after 0 msecs
[   27.907850704] calling  filelock_init+0x0/0x30 @ 1
[   27.907926573] initcall filelock_init+0x0/0x30 returned 0 after 0 msecs
[   27.908071327] calling  init_script_binfmt+0x0/0x10 @ 1
[   27.908165195] initcall init_script_binfmt+0x0/0x10 returned 0 after 0 msecs
[   27.908309461] calling  init_elf_binfmt+0x0/0x10 @ 1

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12 10:17:19 +01:00
Frederic Weisbecker 3f5ec13696 tracing/fastboot: move boot tracer structs and funcs into their own header.
Impact: Cleanups on the boot tracer and ftrace

This patch bring some cleanups about the boot tracer headers. The
functions and structures of this tracer have nothing related to ftrace
and should have so their own header file.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12 10:17:18 +01:00
Ingo Molnar cf569a9322 sched: clean up tracepoints
make it a bit more structured hence more readable.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:33:14 +02:00
Mathieu Desnoyers 0a16b60758 tracing, sched: LTTng instrumentation - scheduler
Instrument the scheduler activity (sched_switch, migration, wakeups,
wait for a task, signal delivery) and process/thread
creation/destruction (fork, exit, kthread stop). Actually, kthread
creation is not instrumented in this patch because it is architecture
dependent. It allows to connect tracers such as ftrace which detects
scheduling latencies, good/bad scheduler decisions. Tools like LTTng can
export this scheduler information along with instrumentation of the rest
of the kernel activity to perform post-mortem analysis on the scheduler
activity.

About the performance impact of tracepoints (which is comparable to
markers), even without immediate values optimizations, tests done by
Hideo Aoki on ia64 show no regression. His test case was using hackbench
on a kernel where scheduler instrumentation (about 5 events in code
scheduler code) was added. See the "Tracepoints" patch header for
performance result detail.

Changelog :

- Change instrumentation location and parameter to match ftrace
  instrumentation, previously done with kernel markers.

[ mingo@elte.hu: conflict resolutions ]
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: 'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:30:52 +02:00