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
..
irq
tracing, genirq: add irq enter and exit trace events
2009-02-26 18:43:50 +01:00
power
PM: Split up sysdev_[suspend|resume] from device_power_[down|up]
2009-02-22 10:33:44 -08:00
time
hrtimers: allow the hot-unplugging of all cpus
2009-01-30 22:35:29 +01:00
trace
tracing: new format for specialized trace points
2009-03-10 00:35:07 -04:00
.gitignore
acct.c
[CVE-2009-0029] System call wrappers part 04
2009-01-14 14:15:19 +01:00
async.c
async: use list_move_tail
2009-02-08 10:00:26 -08:00
audit.c
[PATCH] fix broken timestamps in AVC generated by kernel threads
2008-12-09 02:27:41 -05:00
audit.h
fixing audit rule ordering mess, part 1
2009-01-04 15:14:41 -05:00
audit_tree.c
audit: validate comparison operations, store them in sane form
2009-01-04 15:14:42 -05:00
auditfilter.c
audit: validate comparison operations, store them in sane form
2009-01-04 15:14:42 -05:00
auditsc.c
make sure that filterkey of task,always rules is reported
2009-01-04 15:14:42 -05:00
backtracetest.c
bounds.c
capability.c
[CVE-2009-0029] System call wrappers part 04
2009-01-14 14:15:19 +01:00
cgroup.c
cgroups: fix possible use after free
2009-02-18 15:37:54 -08:00
cgroup_debug.c
cgroups: fix probable race with put_css_set[_taskexit] and find_css_set
2008-10-20 08:52:38 -07:00
cgroup_freezer.c
freezer_cg: disable writing freezer.state of root cgroup
2008-11-12 17:17:16 -08:00
compat.c
Allow times and time system calls to return small negative values
2009-01-06 15:59:13 -08:00
configs.c
kernel/configs.c: remove useless comments
2008-10-20 08:52:34 -07:00
cpu.c
stop_machine/cpu hotplug: fix disable_nonboot_cpus
2009-01-07 11:36:14 -08:00
cpuset.c
cpuset: fix possible deadlock in async_rebuild_sched_domains
2009-01-19 02:44:00 +01:00
cred-internals.h
CRED: Inaugurate COW credentials
2008-11-14 10:39:23 +11:00
cred.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
2009-01-09 13:59:25 -08:00
delayacct.c
schedstat: consolidate per-task cpu runtime stats
2008-12-18 13:54:01 +01:00
dma-coherent.c
dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy.
2009-01-21 18:51:53 +09:00
dma.c
kernel/dma.c: remove a CVS keyword
2008-10-16 11:21:30 -07:00
exec_domain.c
[CVE-2009-0029] System call wrappers part 04
2009-01-14 14:15:19 +01:00
exit.c
signal: re-add dead task accumulation stats.
2009-02-05 13:04:33 +01:00
extable.c
tracing/function-graph-tracer: drop the kernel_text_address check
2009-02-09 10:51:38 +01:00
fork.c
Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2009-02-11 08:24:32 -08:00
freezer.c
freezer_cg: use thaw_process() in unfreeze_cgroup()
2008-10-30 11:38:45 -07:00
futex.c
futex: fix reference leak
2009-02-11 18:24:08 +01:00
futex_compat.c
CRED: Use RCU to access another task's creds and to release a task's own creds
2008-11-14 10:39:19 +11:00
hrtimer.c
hrtimer: prevent negative expiry value after clock_was_set()
2009-01-30 22:35:34 +01:00
itimer.c
timers: split process wide cpu clocks/timers
2009-02-05 13:04:33 +01:00
kallsyms.c
Revert "kbuild: strip generated symbols from *.ko"
2009-01-14 21:38:20 +01:00
Kconfig.freezer
container freezer: implement freezer cgroup subsystem
2008-10-20 08:52:34 -07:00
Kconfig.hz
Kconfig.preempt
rcu: provide RCU options on non-preempt architectures too
2008-12-25 09:31:28 +01:00
kexec.c
PM: Split up sysdev_[suspend|resume] from device_power_[down|up]
2009-02-22 10:33:44 -08:00
kfifo.c
kgdb.c
kgdb: call touch_softlockup_watchdog on resume
2008-10-06 13:50:59 -05:00
kmod.c
kmod: fix varargs kernel-doc
2009-01-06 15:59:27 -08:00
kprobes.c
kprobes: check CONFIG_FREEZER instead of CONFIG_PM
2009-01-16 14:32:17 -05:00
ksysfs.c
kernel/ksysfs.c:fix dependence on CONFIG_NET
2009-01-06 10:44:31 -08:00
kthread.c
tracepoints: add DECLARE_TRACE() and DEFINE_TRACE()
2008-11-16 09:01:36 +01:00
latencytop.c
KSYM_SYMBOL_LEN fixes
2008-12-10 08:01:54 -08:00
lockdep.c
tracing: add lockdep tracepoints for lock acquire/release
2009-03-04 18:49:58 +01:00
lockdep_internals.h
lockdep: get_user_chars() redo
2009-02-14 23:28:22 +01:00
lockdep_proc.c
lockstat: warn about disabled lock debugging
2009-02-14 23:28:28 +01:00
lockdep_states.h
lockdep: move state bit definitions around
2009-02-14 23:27:59 +01:00
Makefile
PM: fix build for CONFIG_PM unset
2009-02-21 14:17:17 -08:00
marker.c
markers/tracpoints: fix non-modular build
2008-11-16 09:52:03 +01:00
module.c
tracing: trace_bprintk() cleanups
2009-03-06 17:59:12 +01:00
mutex-debug.c
mutex: implement adaptive spinning
2009-01-14 18:09:02 +01:00
mutex-debug.h
mutex: implement adaptive spinning
2009-01-14 18:09:02 +01:00
mutex.c
mutex: adaptive spinnning, performance tweaks
2009-01-14 19:03:54 +01:00
mutex.h
mutex: implement adaptive spinning
2009-01-14 18:09:02 +01:00
notifier.c
Merge commit 'v2.6.28-rc6' into core/debug
2008-11-26 08:22:50 +01:00
ns_cgroup.c
ns_cgroup: remove unused spinlock
2009-01-08 08:31:02 -08:00
nsproxy.c
User namespaces: set of cleanups (v2)
2008-11-24 18:57:41 -05:00
panic.c
oops: increment the oops UUID every time we oops
2009-01-06 15:59:12 -08:00
params.c
Fix compile warning in kernel/params.c
2008-10-23 12:09:00 -07:00
pid.c
pid: generalize task_active_pid_ns
2009-01-08 08:31:12 -08:00
pid_namespace.c
pm_qos_params.c
posix-cpu-timers.c
timers: more consistently use clock vs timer
2009-02-13 13:04:05 +01:00
posix-timers.c
[CVE-2009-0029] System call wrappers part 05
2009-01-14 14:15:20 +01:00
printk.c
PM: Fix suspend_console and resume_console to use only one semaphore
2009-02-21 14:17:18 -08:00
profile.c
profiling: fix broken profiling regression
2009-02-10 00:50:37 +01:00
ptrace.c
[CVE-2009-0029] System call wrappers part 27
2009-01-14 14:15:29 +01:00
rcuclassic.c
rcu: Teach RCU that idle task is not quiscent state at boot
2009-02-26 04:08:14 +01:00
rcupdate.c
rcu: Teach RCU that idle task is not quiscent state at boot
2009-02-26 04:08:14 +01:00
rcupreempt.c
rcu: Teach RCU that idle task is not quiscent state at boot
2009-02-26 04:08:14 +01:00
rcupreempt_trace.c
"Tree RCU": scalable classic RCU implementation
2008-12-18 21:56:04 +01:00
rcutorture.c
rcu: fix bug in rcutorture system-shutdown code
2009-01-07 23:36:25 +01:00
rcutree.c
rcu: Teach RCU that idle task is not quiscent state at boot
2009-02-26 04:08:14 +01:00
rcutree_trace.c
"Tree RCU": scalable classic RCU implementation
2008-12-18 21:56:04 +01:00
relay.c
Merge branches 'tracing/ftrace', 'tracing/kmemtrace' and 'linus' into tracing/core
2009-02-03 06:25:38 +01:00
res_counter.c
memcg: memory cgroup resource counters for hierarchy
2009-01-08 08:31:05 -08:00
resource.c
resources: fix parameter name and kernel-doc
2009-01-15 16:39:38 -08:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c
Merge branch 'core/locking' into tracing/ftrace
2009-03-04 18:49:19 +01:00
sched_clock.c
Merge branch 'sched/clock' into tracing/ftrace
2009-02-27 08:35:19 +01:00
sched_cpupri.c
sched: fix section mismatch
2009-01-06 11:07:15 +01:00
sched_cpupri.h
sched: convert struct cpupri_vec cpumask_var_t.
2008-11-24 17:52:22 +01:00
sched_debug.c
sched: partly revert "sched debug: remove NULL checking in print_cfs_rt_rq()"
2009-01-11 02:40:32 +01:00
sched_fair.c
sched: revert recent sync wakeup changes
2009-02-11 14:43:35 +01:00
sched_features.h
mutex: implement adaptive spinning
2009-01-14 18:09:02 +01:00
sched_idletask.c
sched: add CONFIG_SMP consistency
2008-10-22 10:01:52 +02:00
sched_rt.c
sched_rt: don't use first_cpu on cpumask created with cpumask_and
2009-02-01 10:49:52 +01:00
sched_stats.h
timers: split process wide cpu clocks/timers
2009-02-05 13:04:33 +01:00
seccomp.c
x86-64: seccomp: fix 32/64 syscall hole
2009-03-02 15:41:30 -08:00
semaphore.c
signal.c
signal: re-add dead task accumulation stats.
2009-02-05 13:04:33 +01:00
smp.c
generic-ipi: use per cpu data for single cpu ipi calls
2009-01-30 18:31:08 +01:00
softirq.c
trace, lockdep: manual preempt count adding for local_bh_disable
2009-01-23 11:10:57 +01:00
softlockup.c
softlock: fix false panic which can occur if softlockup_thresh is reduced
2009-01-14 11:48:07 +01:00
spinlock.c
srcu.c
stacktrace.c
stacktrace: provide save_stack_trace_tsk() weak alias
2008-12-25 11:44:43 +01:00
stop_machine.c
stop_machine: introduce stop_machine_create/destroy.
2009-01-05 08:40:14 +10:30
sys.c
sched: don't allow setuid to succeed if the user does not have rt bandwidth
2009-02-27 11:11:53 +01:00
sys_ni.c
[CVE-2009-0029] Make sys_syslog a conditional system call
2009-01-14 14:15:16 +01:00
sysctl.c
mm: fix dirty_bytes/dirty_background_bytes sysctls on 64bit arches
2009-02-11 14:25:35 -08:00
sysctl_check.c
[XFS] remove restricted chown parameter from xfs linux
2008-10-30 18:30:09 +11:00
taskstats.c
cpumask: convert rest of files in kernel/
2009-01-01 10:12:28 +10:30
test_kprobes.c
kprobes: add tests for register_kprobes
2009-01-06 15:59:20 -08:00
time.c
[CVE-2009-0029] System call wrappers part 01
2009-01-14 14:15:18 +01:00
timeconst.pl
timer.c
timer: implement lockdep deadlock detection
2009-02-14 23:25:52 +01:00
tracepoint.c
markers/tracpoints: fix non-modular build
2008-11-16 09:52:03 +01:00
tsacct.c
mm: introduce get_mm_hiwater_xxx(), fix taskstats->hiwater_xxx accounting
2009-01-06 15:59:09 -08:00
uid16.c
[CVE-2009-0029] System call wrappers part 19
2009-01-14 14:15:26 +01:00
up.c
smp_call_function_single(): be slightly less stupid, fix #2
2009-01-12 16:04:37 +01:00
user.c
sched: don't allow setuid to succeed if the user does not have rt bandwidth
2009-02-27 11:11:53 +01:00
user_namespace.c
Fix recursive lock in free_uid()/free_user_ns()
2009-02-27 16:26:21 -08:00
utsname.c
utsname_sysctl.c
sysctl: simplify ->strategy
2008-10-16 11:21:47 -07:00
wait.c
wait: prevent exclusive waiter starvation
2009-02-05 12:56:48 -08:00
workqueue.c
Merge branches 'tracing/ftrace', 'tracing/kmemtrace' and 'linus' into tracing/core
2009-02-03 06:25:38 +01:00