Commit graph

8411 commits

Author SHA1 Message Date
Steven Rostedt
a123c52b46 tracing: fix comments about trace buffer resizing
Impact: cleanup

Some of the comments about the trace buffer resizing is gobbledygook.
And I wonder why people question if I'm a native English speaker.

This patch makes the comments make a bit more sense.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-12 21:14:58 -04:00
Ingo Molnar
25d500067d Merge branch 'linus' into core/ipi 2009-03-13 02:14:25 +01:00
Steven Rostedt
51b643b404 Merge branch 'tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/ftrace-merge 2009-03-12 21:12:46 -04:00
Ingo Molnar
480c93df5b Merge branch 'core/locking' into tracing/ftrace 2009-03-13 01:33:21 +01:00
Ingo Molnar
d820ac4c2f locking: rename trace_softirq_[enter|exit] => lockdep_softirq_[enter|exit]
Impact: cleanup

The naming clashes with upcoming softirq tracepoints, so rename the
APIs to lockdep_*().

Requested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13 01:32:36 +01:00
Ingo Molnar
3c1f67d60e Merge branch 'linus' into core/locking 2009-03-13 01:29:17 +01:00
Darren Hart
f061d35150 futex: remove the pointer math from double_unlock_hb
Impact: simplify code

I mistakenly included the pointer value ordering in the
double_unlock_hb() in my previous patch. It's only necessary
in the double_lock_hb() function. This patch removes it.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090312221118.11146.68610.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13 01:15:46 +01:00
Magnus Damm
eb53b4e8fe irq: export remove_irq() and setup_irq() symbols
Export the setup_irq() and remove_irq() symbols.

I'd like to export these functions since I have timer
code that needs to use setup_irq() early on (too early
for request_irq()), and the same code can also be
compiled as a module.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
LKML-Reference: <20090312120559.2926.82371.sendpatchset@rx1.opensource.se>
[ changed to _GPL as these are special APIs deep inside the irq layer. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 13:16:33 +01:00
Magnus Damm
cbf94f0682 irq: match remove_irq() args with setup_irq()
Modify remove_irq() to match setup_irq().

Signed-off-by: Magnus Damm <damm@igel.co.jp>
LKML-Reference: <20090312120551.2926.43942.sendpatchset@rx1.opensource.se>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 13:16:33 +01:00
Magnus Damm
f21cfb258d irq: add remove_irq() for freeing of setup_irq() irqs
Impact: add new API

This patch adds a remove_irq() function for releasing
interrupts requested with setup_irq().

Without this patch we have no way of releasing such
interrupts since free_irq() today tries to kfree()
the irqaction passed with setup_irq().

Signed-off-by: Magnus Damm <damm@igel.co.jp>
LKML-Reference: <20090312120542.2926.56609.sendpatchset@rx1.opensource.se>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 13:16:32 +01:00
Ingo Molnar
f8cb22cbb8 Merge branch 'linus' into irq/genirq 2009-03-12 13:16:18 +01:00
Darren Hart
e4dc5b7a36 futex: clean up fault logic
Impact: cleanup

Older versions of the futex code held the mmap_sem which had to
be dropped in order to call get_user(), so a two-pronged fault
handling mechanism was employed to handle faults of the atomic
operations.  The mmap_sem is no longer held, so get_user()
should be adequate.  This patch greatly simplifies the logic and
improves legibility.

Build and boot tested on a 4 way Intel x86_64 workstation.
Passes basic pthread_mutex and PI tests out of
ltp/testcases/realtime.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090312075612.9856.48612.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 11:20:57 +01:00
Darren Hart
e8f6386c01 futex: unlock before returning -EFAULT
Impact: rt-mutex failure case fix

futex_lock_pi can potentially return -EFAULT with the rt_mutex
held.  This seems like the wrong thing to do as userspace should
assume -EFAULT means the lock was not taken.  Even if it could
figure this out, we'd be leaving the pi_state->owner in an
inconsistent state.  This patch unlocks the rt_mutex prior to
returning -EFAULT to userspace.

Build and boot tested on a 4 way Intel x86_64 workstation.
Passes basic pthread_mutex and PI tests out of
ltp/testcases/realtime.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090312075606.9856.88729.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 11:20:57 +01:00
Darren Hart
16f4993f4e futex: use current->time_slack_ns for rt tasks too
RT tasks should set their timer slack to 0 on their own.  This
patch removes the 'if (rt_task()) slack = 0;' block in
futex_wait.

Build and boot tested on a 4 way Intel x86_64 workstation.
Passes basic pthread_mutex and PI tests out of
ltp/testcases/realtime.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <20090312075559.9856.28822.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 11:20:57 +01:00
Darren Hart
5eb3dc62fc futex: add double_unlock_hb()
Impact: cleanup

The futex code uses double_lock_hb() which locks the hb->lock's
in pointer value order.  There is no parallel unlock routine,
and the code unlocks them in name order, ignoring pointer value.

This patch adds double_unlock_hb() to refactor the duplicated
code segments.

Build and boot tested on a 4 way Intel x86_64 workstation.
Passes basic pthread_mutex and PI tests out of
ltp/testcases/realtime.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090312075552.9856.48021.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 11:20:56 +01:00
Darren Hart
de87fcc124 futex: additional (get|put)_futex_key() fixes
Impact: fix races

futex_requeue and futex_lock_pi still had some bad
(get|put)_futex_key() usage. This patch adds the missing
put_futex_keys() and corrects a goto in futex_lock_pi() to avoid
a double get.

Build and boot tested on a 4 way Intel x86_64 workstation.
Passes basic pthread_mutex and PI tests out of
ltp/testcases/realtime.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090312075545.9856.75152.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 11:20:56 +01:00
Darren Hart
b2d0994b13 futex: update futex commentary
Impact: cleanup

The futex_hash_bucket can be a bit confusing when first looking
at the code as it is a shared queue (and futex_q isn't a queue
at all, but rather an element on the queue).

The mmap_sem is no longer held outside of the
futex_handle_fault() routine, yet numerous comments refer to it.
The fshared argument is no an integer.  I left some of these
comments along as they are simply removed in future patches.

Some of the commentary refering to futexes by virtual page
mappings was not very clear, and completely accurate (as for
shared futexes both the page and the offset are used to
determine the key).  For the purposes of the function
description, just referring to "the futex" seems sufficient.

With hashed futexes we now access the page after the hash-bucket
is locked, and not only after it is enqueued.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <20090312075537.9856.29954.stgit@Aeon>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12 11:20:55 +01:00
Steven Rostedt
554f786e28 ring-buffer: only allocate buffers for online cpus
Impact: save on memory

Currently, a ring buffer was allocated for each "possible_cpus". On
some systems, this is the same as NR_CPUS. Thus, if a system defined
NR_CPUS = 64 but it only had 1 CPU, we could have possibly 63 useless
ring buffers taking up space. With a default buffer of 3 megs, this
could be quite drastic.

This patch changes the ring buffer code to only allocate ring buffers
for online CPUs.  If a CPU goes off line, we do not free the buffer.
This is because the user may still have trace data in that buffer
that they would like to look at.

Perhaps in the future we could add code to delete a ring buffer if
the CPU is offline and the ring buffer becomes empty.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-11 22:15:27 -04:00
Steven Rostedt
9aba60fe6e tracing: fix trace_wait to know to wait on all cpus or just one
Impact: fix to task live locking on reading trace_pipe on one CPU

The same code is used for both trace_pipe (all CPUS) and the per_cpu
trace_pipe file. When there is no data to read, it will check for
signals and wait on the trace wait queue.

The problem happens with the per_cpu wait. The trace_wait code checks
all CPUs. Thus, if there's data in another CPU buffer, then it will
exit the wait, without checking for signals or waiting on the wait queue.

It would then try to read the empty buffer, and since that will just
return nothing, then it will try to wait again. Unfortunately, that will
again fail due to there still being data in the other buffers. This
ends up with a live lock for the task.

This patch fixes the trace_wait to be aware that the iterator may only
be waiting on a single buffer.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-11 22:15:25 -04:00
Steven Rostedt
1852fcce18 tracing: expand the ring buffers when an event is activated
To save memory, the tracer ring buffers are set to a minimum.
The activating of a trace expands the ring buffer size. This patch
adds this expanding, when an event is activated.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-11 22:15:24 -04:00
Steven Rostedt
73c5162aa3 tracing: keep ring buffer to minimum size till used
Impact: less memory impact on systems not using tracer

When the kernel boots up that has tracing configured, it allocates
the default size of the ring buffer. This currently happens to be
1.4Megs per possible CPU. This is quite a bit of wasted memory if
the system is never using the tracer.

The current solution is to keep the ring buffers to a minimum size
until the user uses them. Once a tracer is piped into the current_tracer
the ring buffer will be expanded to the default size. If the user
changes the size of the ring buffer, it will take the size given
by the user immediately.

If the user adds a "ftrace=" to the kernel command line, then the ring
buffers will be set to the default size on initialization.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-11 22:15:22 -04:00
Ingo Molnar
aecfcde920 Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace 2009-03-11 20:47:23 +01:00
Mike Galbraith
df1c99d416 sched: add avg_overlap decay
Impact: more precise avg_overlap metric - better load-balancing

avg_overlap is used to measure the runtime overlap of the waker and
wakee.

However, when a process changes behaviour, eg a pipe becomes
un-congested and we don't need to go to sleep after a wakeup
for a while, the avg_overlap value grows stale.

When running we use the avg runtime between preemption as a
measure for avg_overlap since the amount of runtime can be
correlated to cache footprint.

The longer we run, the less likely we'll be wanting to be
migrated to another CPU.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1236709131.25234.576.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-11 11:31:50 +01:00
Ingo Molnar
78b020d035 Merge branches 'x86/cleanups', 'x86/kexec', 'x86/mce2' and 'linus' into x86/core 2009-03-11 10:49:15 +01:00
Benjamin Herrenschmidt
e14eee56c2 Merge commit 'origin/master' into next 2009-03-11 17:10:07 +11:00
Dhaval Giani
be50b8342d kernel/user.c: fix a memory leak when freeing up non-init usernamespaces users
We were returning early in the sysfs directory cleanup function if the
user belonged to a non init usernamespace.  Due to this a lot of the
cleanup was not done and we were left with a leak.  Fix the leak.

Reported-by: Serge Hallyn <serue@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Tested-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-10 15:55:11 -07:00
Ingo Molnar
e2b8b28085 Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace 2009-03-10 22:55:31 +01:00
Ingo Molnar
4dd163a051 Merge branches 'tracing/ftrace', 'tracing/textedit' and 'linus' into tracing/core 2009-03-10 22:54:23 +01:00
Steven Rostedt
80370cb758 tracing: use raw spinlocks for trace_vprintk
Impact: prevent locking up by lockdep tracer

The lockdep tracer uses trace_vprintk and thus trace_vprintk can not
call back into lockdep without locking up.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 17:16:35 -04:00
Peter Zijlstra
6cc3c6e12b trace_clock: fix preemption bug
Using the function_graph tracer in recent kernels generates a spew of
preemption BUGs. Fix this by not requiring trace_clock_local() users
to disable preemption themselves.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 20:03:01 +01:00
Steven Rostedt
ef18012b24 tracing: remove funky whitespace in the trace code
Impact: clean up

There existed a lot of <space><tab>'s in the tracing code. This
patch removes them.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 14:13:14 -04:00
Steven Rostedt
0e3d0f0566 tracing: update comments to match event code macros
Impact: clean up / comments

The comments that described the ftrace macros to manipulate the
TRACE_EVENT and TRACE_FORMAT macros no longer match the code.
This patch updates them.

Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 13:12:58 -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
2314c4ae14 tracing: add back the available_events file
The event directory files type and available_types were no longer
needed with the new TRACE_EVENT_FORMAT macros, they were deleted.
But by accident the available_events file was also removed.
This patch brings it back.

Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 12:04:02 -04:00
Peter Zijlstra
57310a98a3 sched: optimize ttwu vs group scheduling
Impact: micro-optimization

We can avoid the sched domain walk on try_to_wake_up() when we know
there are no groups.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1236603381.8389.455.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 16:43:36 +01:00
Ingo Molnar
8c54436ae9 Merge branches 'sched/cleanups' and 'linus' into sched/core 2009-03-10 16:34:43 +01:00
Steven Rostedt
40e26815fa tracing: do not allow modifying the ftrace events via the event files
Impact: fix to prevent crash on calling NULL function pointer

The ftrace internal records have their format exported via the event
system under the ftrace subsystem. These are only for exporting the
format to allow binary readers to be able to parse them in a binary
output.

The ftrace subsystem events can only be enabled via the ftrace tracers
and do not have a registering function. The event files expect the
event record to have registering function and will call it directly.
Passing in a ftrace subsystem event will cause the kernel to crash
because it will execute a NULL pointer.

This patch prevents the ftrace subsystem from being viewable to the
event enabling files.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 11:32:40 -04:00
Steven Rostedt
ce8eb2bf05 tracing: fix printk format specifier
Impact: clean up

The offsetof and sizeof are of type size_t, and instead of typecasting
them to unsigned int for printk formatting, one could just use %zu.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 10:14:35 -04:00
Américo Wang
bbb76b552a ptrace: remove a useless goto
Impact: cleanup

Obviously, this goto is useless. Remove it.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Roland McGrath <roland@redhat.com>
LKML-Reference: <20090310093447.GC3179@hack>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 13:39:29 +01:00
KOSAKI Motohiro
bbcd306359 tracing: Don't assume possible cpu list have continuous numbers
"for (++cpu ; cpu < num_possible_cpus(); cpu++)" statement assumes
possible cpus have continuous number - but that's a wrong assumption.

Insted, cpumask_next() should be used.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090310104437.A480.A69D9226@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 10:20:30 +01:00
Ingo Molnar
8293dd6f86 Merge branch 'x86/core' into tracing/ftrace
Semantic merge:

  kernel/trace/trace_functions_graph.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 10:17:48 +01:00
Ingo Molnar
9a1043d19c Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace 2009-03-10 09:57:16 +01:00
Ingo Molnar
12e87e36e0 Merge branches 'tracing/doc', 'tracing/ftrace', 'tracing/printk' and 'linus' into tracing/core 2009-03-10 09:56:25 +01:00
Ingo Molnar
467c88fee5 Merge branches 'x86/apic', 'x86/asm', 'x86/fixmap', 'x86/memtest', 'x86/mm', 'x86/urgent', 'linus' and 'core/percpu' into x86/core 2009-03-10 09:26:38 +01:00
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
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
9cc26a261d tracing: use generic __stringify
Impact: clean up

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

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:35:05 -04:00
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
Steven Rostedt
156b5f172a tracing: typecast sizeof and offsetof to unsigned int
Impact: fix compiler warnings

On x86_64 sizeof and offsetof are treated as long, where as on x86_32
they are int. This patch typecasts them to unsigned int to avoid
one arch giving warnings while the other does not.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-10 00:34:03 -04:00
Oleg Nesterov
2d5516cbb9 copy_process: fix CLONE_PARENT && parent_exec_id interaction
CLONE_PARENT can fool the ->self_exec_id/parent_exec_id logic. If we
re-use the old parent, we must also re-use ->parent_exec_id to make
sure exit_notify() sees the right ->xxx_exec_id's when the CLONE_PARENT'ed
task exits.

Also, move down the "p->parent_exec_id = p->self_exec_id" thing, to place
two different cases together.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-09 13:23:25 -07:00