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Li Zefan e870e9a124 tracing: Allow to disable cmdline recording 
We found that even enabling a single trace event that will rarely be
triggered can add big overhead to context switch.

(lmbench context switch test)
 -------------------------------------------------
 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
 ctxsw  ctxsw  ctxsw ctxsw  ctxsw   ctxsw   ctxsw
------ ------ ------ ------ ------ ------- -------
  2.19   2.3   2.21   2.56   2.13     2.54    2.07
  2.39   2.51  2.35   2.75   2.27     2.81    2.24

The overhead is 6% ~ 11%.

It's because when a trace event is enabled 3 tracepoints (sched_switch,
sched_wakeup, sched_wakeup_new) will be activated to map pid to cmdname.

We'd like to avoid this overhead, so add a trace option '(no)record-cmd'
to allow to disable cmdline recording.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4C2D57F4.2050204@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
 		2010-07-20 21:52:33 -04:00
..
debug module: fix kdb's illicit use of struct module_use. 2010-06-05 11:17:36 +09:30
gcov microblaze: Enable GCOV_PROFILE_ALL 2009-09-21 14:29:21 +02:00
irq genirq: Deal with desc->set_type() changing desc->chip 2010-06-09 17:05:08 +02:00
power suspend: Move NVS save/restore code to generic suspend functionality 2010-06-10 11:02:34 -04:00
time Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-07-02 09:52:58 -07:00
trace tracing: Allow to disable cmdline recording 2010-07-20 21:52:33 -04:00
.gitignore
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Kconfig.freezer
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Kconfig.hz
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Kconfig.locks mutex: Better control mutex adaptive spinning config 2009-12-03 11:50:11 +01:00
Kconfig.preempt
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Makefile Move kernel/kgdb.c to kernel/debug/debug_core.c 2010-05-20 21:04:18 -05:00
acct.c Merge branch 'next' into for-linus 2010-05-18 08:57:00 +10:00
async.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit.h Fix rule eviction order for AUDIT_DIR 2009-06-24 00:02:38 -04:00
audit_tree.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit_watch.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
auditfilter.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
auditsc.c audit: preface audit printk with audit 2010-04-05 13:19:45 -07:00
backtracetest.c
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bounds.c kbuild: move bounds.h to include/generated 2009-12-12 13:08:14 +01:00
capability.c sched: Remove remaining USER_SCHED code 2010-04-02 20:12:00 +02:00
cgroup.c cgroups: alloc_css_id() increments hierarchy depth 2010-06-04 15:21:45 -07:00
cgroup_freezer.c Freezer / cgroup freezer: Update stale locking comments 2010-05-10 23:18:47 +02:00
compat.c cpumask: fix compat getaffinity 2010-05-19 11:48:18 -07:00
configs.c
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cpu.c fix cpu_chain section mismatch... 2010-06-01 09:22:50 -07:00
cpuset.c cpusets: new round-robin rotor for SLAB allocations 2010-05-27 09:12:44 -07:00
cred.c umh: creds: kill subprocess_info->cred logic 2010-05-27 09:12:45 -07:00
delayacct.c headers: taskstats_kern.h trim 2009-09-18 09:48:52 -07:00
dma.c
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early_res.c x86: Do not free zero sized per cpu areas 2010-03-29 18:55:40 +02:00
elfcore.c elf coredump: add extended numbering support 2010-03-06 11:26:46 -08:00
exec_domain.c sys_personality: change sys_personality() to accept "unsigned int" instead of u_long 2010-06-04 15:21:45 -07:00
exit.c proc: turn signal_struct->count into "int nr_threads" 2010-05-27 09:12:47 -07:00
extable.c
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fork.c Revert "cpusets: randomize node rotor used in cpuset_mem_spread_node()" 2010-05-30 09:00:03 -07:00
freezer.c sched: fix nr_uninterruptible accounting of frozen tasks really 2009-07-18 14:19:53 +02:00
futex.c futex: futex_find_get_task remove credentails check 2010-06-30 15:43:44 -07:00
futex_compat.c futex: Protect pid lookup in compat code with RCU 2009-12-09 14:22:14 +01:00
groups.c security: remove dead hook task_setgroups 2010-04-12 12:19:18 +10:00
hrtimer.c hrtimer: Avoid double seqlock 2010-05-26 16:15:37 +02:00
hung_task.c softlockup: Fix hung_task_check_count sysctl 2009-11-27 06:21:57 +01:00
hw_breakpoint.c hw_breakpoints: Fix per task breakpoint tracking 2010-06-24 23:33:40 +02:00
itimer.c itimers: Fix racy writes to cpu_itimer fields 2009-11-18 16:32:12 +01:00
kallsyms.c kdb: core for kgdb back end (2 of 2) 2010-05-20 21:04:21 -05:00
kexec.c kexec: fix Oops in crash_shrink_memory() 2010-06-29 15:29:31 -07:00
kfifo.c kfifo: Don't use integer as NULL pointer 2010-02-16 15:11:08 -08:00
kmod.c call_usermodehelper: UMH_WAIT_EXEC ignores kernel_thread() failure 2010-05-27 09:12:45 -07:00
kprobes.c kprobes: Move enable/disable_kprobe() out from debugfs code 2010-05-08 18:08:30 +02:00
ksysfs.c sysfs: add struct file* to bin_attr callbacks 2010-05-21 09:37:31 -07:00
kthread.c cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node 2010-03-24 16:31:21 -07:00
latencytop.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
lockdep.c lockdep: Add novalidate class for dev->mutex conversion 2010-05-21 09:37:30 -07:00
lockdep_internals.h lockdep: No need to disable preemption in debug atomic ops 2010-05-04 05:38:16 +02:00
lockdep_proc.c lockstat: Make lockstat counting per cpu 2010-04-06 00:15:37 +02:00
lockdep_states.h
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module.c module: initialize module dynamic debug later 2010-07-04 20:17:22 -07:00
mutex-debug.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
mutex-debug.h locking: Implement new raw_spinlock 2009-12-14 23:55:32 +01:00
mutex.c mutex: Fix optimistic spinning vs. BKL 2010-05-19 08:18:44 +02:00
mutex.h
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notifier.c sched: Use lockdep-based checking on rcu_dereference() 2010-02-25 10:34:26 +01:00
ns_cgroup.c cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time 2009-09-24 07:20:58 -07:00
nsproxy.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
padata.c kernel/: convert cpu notifier to return encapsulate errno value 2010-05-27 09:12:48 -07:00
panic.c panic: call console_verbose() in panic 2010-05-27 09:12:53 -07:00
params.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-03-12 16:04:50 -08:00
perf_event.c Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core 2010-06-09 18:55:57 +02:00
pid.c pids: increase pid_max based on num_possible_cpus 2010-05-27 09:12:51 -07:00
pid_namespace.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
pm_qos_params.c PM: PM QOS update fix 2010-05-17 00:21:03 +02:00
posix-cpu-timers.c posix-cpu-timers: avoid "task->signal != NULL" checks 2010-05-27 09:12:46 -07:00
posix-timers.c posix_timer: Fix error path in timer_create 2010-05-27 22:38:15 +02:00
printk.c printk,kdb: capture printk() when in kdb shell 2010-05-20 21:04:27 -05:00
profile.c numa: in-kernel profiling: use cpu_to_mem() for per cpu allocations 2010-05-27 09:12:57 -07:00
ptrace.c ptrace: PTRACE_GETFDPIC: fix the unsafe usage of child->mm 2010-05-27 09:12:44 -07:00
range.c x86: Change range end to start+size 2010-02-10 17:47:17 -08:00
rcupdate.c rcu: slim down rcutiny by removing rcu_scheduler_active and friends 2010-05-10 11:08:34 -07:00
rcutiny.c rcu: remove all rcu head initializations, except on_stack initializations 2010-05-11 16:10:47 -07:00
rcutiny_plugin.h rcu: slim down rcutiny by removing rcu_scheduler_active and friends 2010-05-10 11:08:34 -07:00
rcutorture.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:27:54 -07:00
rcutree.c rcu: remove all rcu head initializations, except on_stack initializations 2010-05-11 16:10:47 -07:00
rcutree.h rcu: reduce the number of spurious RCU_SOFTIRQ invocations 2010-05-10 11:08:35 -07:00
rcutree_plugin.h rcu: remove all rcu head initializations, except on_stack initializations 2010-05-11 16:10:47 -07:00
rcutree_trace.c rcu: reduce the number of spurious RCU_SOFTIRQ invocations 2010-05-10 11:08:35 -07:00
relay.c kernel/: convert cpu notifier to return encapsulate errno value 2010-05-27 09:12:48 -07:00
res_counter.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
resource.c resource: shared I/O region support 2010-05-11 12:01:10 -07:00
rtmutex-debug.c sched: Convert pi_lock to raw_spinlock 2009-12-14 23:55:33 +01:00
rtmutex-debug.h
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rtmutex-tester.c
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rtmutex.c rtmutes: Convert rtmutex.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
rtmutex.h
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rtmutex_common.h
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rwsem.c
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sched.c Merge commit 'v2.6.35-rc4' into perf/core 2010-07-05 08:30:58 +02:00
sched_clock.c blkio: fix for modular blk-cgroup build 2010-04-15 08:54:59 +02:00
sched_cpupri.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sched_cpupri.h sched: Convert cpupri lock to raw_spinlock 2009-12-14 23:55:33 +01:00
sched_debug.c proc_sched_show_task(): use get_nr_threads() 2010-05-27 09:12:47 -07:00
sched_fair.c rcu: apply RCU protection to wake_affine() 2010-06-23 06:50:44 -07:00
sched_features.h sched: Remove ASYM_GRAN feature 2010-03-11 18:32:53 +01:00
sched_idletask.c sched: Cure load average vs NO_HZ woes 2010-04-23 11:02:02 +02:00
sched_rt.c sched: Add enqueue/dequeue flags 2010-04-02 20:12:05 +02:00
sched_stats.h
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seccomp.c
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semaphore.c
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signal.c exit: change zap_other_threads() to count sub-threads 2010-05-27 09:12:46 -07:00
slow-work-debugfs.c SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
slow-work.c slow-work: use get_ref wrapper instead of directly calling get_ref 2010-03-29 09:13:30 -07:00
slow-work.h SLOW_WORK: CONFIG_SLOW_WORK_PROC should be CONFIG_SLOW_WORK_DEBUG 2010-03-29 09:14:47 -07:00
smp.c kernel/: convert cpu notifier to return encapsulate errno value 2010-05-27 09:12:48 -07:00
softirq.c kernel/: fix BUG_ON checks for cpu notifier callbacks direct call 2010-06-04 15:21:45 -07:00
softlockup.c softlockup: Stop spurious softlockup messages due to overflow 2010-03-21 19:30:13 +01:00
spinlock.c locking: Cleanup the name space completely 2009-12-14 23:55:33 +01:00
srcu.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
stacktrace.c
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stop_machine.c sched: Make sure timers have migrated before killing the migration_thread 2010-05-31 08:37:44 +02:00
sys.c kmod: add init function to usermodehelper 2010-05-27 09:12:44 -07:00
sys_ni.c Add generic sys_ipc wrapper 2010-03-12 15:52:32 -08:00
sysctl.c pipe: change /proc/sys/fs/pipe-max-pages to byte sized interface 2010-06-03 14:54:39 +02:00
sysctl_binary.c sysctl: don't use own implementation of hex_to_bin() 2010-05-25 08:07:05 -07:00
sysctl_check.c ipv4 05/05: add sysctl to accept packets with local source addresses 2009-12-03 12:14:38 -08:00
taskstats.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
test_kprobes.c
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time.c timekeeping: Fix timezone update 2010-05-24 11:50:38 +02:00
timeconst.pl
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timer.c kernel/: fix BUG_ON checks for cpu notifier callbacks direct call 2010-06-04 15:21:45 -07:00
tracepoint.c tracing: Let tracepoints have data passed to tracepoint callbacks 2010-05-14 09:50:34 -04:00
tsacct.c mm: clean up mm_counter 2010-03-06 11:26:23 -08:00
uid16.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
up.c
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user-return-notifier.c core: Clean up user return notifers use of per_cpu 2009-12-02 10:22:59 +01:00
user.c sched: Remove a stale comment 2010-05-10 08:48:39 +02:00
user_namespace.c kref: remove kref_set 2010-05-21 09:37:29 -07:00
utsname.c utsns: extract creeate_uts_ns() 2009-06-18 13:03:55 -07:00
utsname_sysctl.c sysctl kernel: Remove binary sysctl logic 2009-11-12 02:04:55 -08:00
wait.c locking, sched: Give waitqueue spinlocks their own lockdep classes 2009-08-10 14:43:09 +02:00
workqueue.c kernel/: convert cpu notifier to return encapsulate errno value 2010-05-27 09:12:48 -07:00