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

..

irq

Merge branches 'core-fixes-for-linus', 'irq-fixes-for-linus' and 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-09 10:35:30 -07:00

power

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2009-04-03 15:24:35 -07:00

time

Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-03-26 16:05:42 -07:00

trace

Merge branch 'tracing/urgent' into tracing/core

2009-04-10 12:46:51 +02:00

.gitignore

Update kernel/.gitignore with new auto-generated files

2008-02-09 23:27:01 -08:00

acct.c

[CVE-2009-0029] System call wrappers part 04

2009-01-14 14:15:19 +01:00

async.c

async: remove the temporary (2.6.29) "async is off by default" code

2009-03-28 13:05:30 -07:00

audit_tree.c

audit: incorrect ref counting in audit tree tag_chunk

2009-04-05 13:48:26 -04:00

audit.c

Audit: remove spaces from audit_log_d_path

2009-04-05 13:49:04 -04:00

audit.h

fixing audit rule ordering mess, part 1

2009-01-04 15:14:41 -05:00

auditfilter.c

make the e->rule.xxx shorter in kernel auditfilter.c

2009-04-05 13:40:33 -04:00

auditsc.c

Audit: remove spaces from audit_log_d_path

2009-04-05 13:49:04 -04:00

backtracetest.c

backtrace: replace timer with tasklet + completions

2008-06-27 18:09:16 +02:00

bounds.c

Add kbuild.h that contains common definitions for kbuild users

2008-04-29 08:06:29 -07:00

capability.c

[CVE-2009-0029] System call wrappers part 04

2009-01-14 14:15:19 +01:00

cgroup_debug.c

debug cgroup: remove unneeded cgroup_lock

2009-04-02 19:04:54 -07:00

cgroup_freezer.c

freezer_cg: disable writing freezer.state of root cgroup

2008-11-12 17:17:16 -08:00

cgroup.c

memcg: fix OOM killer under memcg

2009-04-02 19:04:55 -07:00

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

cpumask: use set_cpu_active in init/main.c

2009-03-30 22:05:12 +10:30

cpuset.c

cpusets: prevent PF_THREAD_BOUND tasks from attaching to non-root cpusets

2009-04-02 19:04:57 -07:00

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

Get rid of indirect include of fs_struct.h

2009-03-31 23:00:27 -04:00

exit.c

Merge branch 'irq/threaded' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-07 14:07:52 -07:00

extable.c

Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-05 11:04:19 -07:00

fork.c

Merge branches 'core-fixes-for-linus', 'irq-fixes-for-linus' and 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-09 10:35:30 -07:00

freezer.c

freezer_cg: use thaw_process() in unfreeze_cgroup()

2008-10-30 11:38:45 -07:00

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

futex.c

futex: comment requeue key reference semantics

2009-04-02 23:39:53 +02:00

hrtimer.c

hrtimer: fix rq->lock inversion (again)

2009-03-31 14:52:52 +02:00

hung_task.c

softlockup: ensure the task has been switched out once

2009-02-11 11:04:16 +01:00

itimer.c

timers: split process wide cpu clocks/timers

2009-02-05 13:04:33 +01:00

kallsyms.c

Ksplice: Add functions for walking kallsyms symbols

2009-03-31 13:05:32 +10:30

Kconfig.freezer

container freezer: implement freezer cgroup subsystem

2008-10-20 08:52:34 -07:00

Kconfig.hz

sched: fix SCHED_HRTICK dependency

2008-07-28 14:37:38 +02:00

Kconfig.preempt

rcu: provide RCU options on non-preempt architectures too

2008-12-25 09:31:28 +01:00

kexec.c

kexec: vmcoreinfo_data[] can become static

2009-04-02 19:05:04 -07:00

kfifo.c

…

kgdb.c

kgdb: call touch_softlockup_watchdog on resume

2008-10-06 13:50:59 -05:00

kmod.c

module: create a request_module_nowait()

2009-03-31 13:05:35 +10:30

kprobes.c

kprobes: support per-kprobe disabling

2009-04-07 08:31:08 -07:00

ksysfs.c

kernel/ksysfs.c:fix dependence on CONFIG_NET

2009-01-06 10:44:31 -08:00

kthread.c

kthread: move sched-realeted initialization from kthreadd context

2009-04-09 09:50:37 +09:30

latencytop.c

sched, latencytop: incorporate review feedback from Andrew Morton

2009-02-11 10:18:04 +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

lockdep.c

tracing/lockdep: report the time waited for a lock

2009-04-10 12:50:56 +02:00

Makefile

Merge branch 'linus' into core/softlockup

2009-04-07 11:15:40 +02:00

marker.c

markers/tracpoints: fix non-modular build

2008-11-16 09:52:03 +01:00

module.c

Revert "module: remove the SHF_ALLOC flag on the __versions section."

2009-04-07 17:12:43 +09:30

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

cgroups: relax ns_can_attach checks to allow attaching to grandchild cgroups

2009-04-02 19:04:53 -07:00

nsproxy.c

User namespaces: set of cleanups (v2)

2008-11-24 18:57:41 -05:00

panic.c

panic: clean up kernel/panic.c

2009-03-13 11:25:53 +01:00

params.c

param: fix charp parameters set via sysfs

2009-03-31 13:05:30 +10:30

pid_namespace.c

signals: zap_pid_ns_process() should use force_sig()

2009-04-02 19:04:58 -07:00

pid.c

pids: refactor vnr/nr_ns helpers to make them safe

2009-04-02 19:05:02 -07:00

pm_qos_params.c

pm_qos_requirement might sleep

2008-09-02 19:21:40 -07:00

posix-cpu-timers.c

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-09 10:37:28 -07:00

posix-timers.c

[CVE-2009-0029] System call wrappers part 05

2009-01-14 14:15:20 +01:00

printk.c

Merge branch 'printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-05 10:23:25 -07:00

profile.c

profiling: fix broken profiling regression

2009-02-10 00:50:37 +01:00

ptrace.c

ptrace: some checkpatch fixes

2009-04-08 10:21:44 -07:00

rcuclassic.c

kmemtrace, rcu: fix linux/rcutree.h and linux/rcuclassic.h dependencies

2009-04-03 12:23:02 +02:00

rcupdate.c

rcu: rcu_barrier VS cpu_hotplug: Ensure callbacks in dead cpu are migrated to online cpu

2009-03-31 00:09:37 +02:00

rcupreempt_trace.c

"Tree RCU": scalable classic RCU implementation

2008-12-18 21:56:04 +01:00

rcupreempt.c

kmemtrace, rcu: fix rcupreempt.c data structure dependencies

2009-04-03 12:23:04 +02:00

rcutorture.c

cpumask: convert rcutorture.c

2009-03-30 22:05:16 +10:30

rcutree_trace.c

kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies

2009-04-03 12:23:03 +02:00

rcutree.c

kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies

2009-04-03 12:23:03 +02:00

rcutree.h

kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies

2009-04-03 12:23:03 +02:00

relay.c

Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-05 11:04:19 -07:00

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_common.h

Don't operate with pid_t in rtmutex tester

2008-02-08 09:22:41 -08:00

rtmutex-debug.c

Don't operate with pid_t in rtmutex tester

2008-02-08 09:22:41 -08:00

rtmutex-debug.h

…

rtmutex-tester.c

sysdev: Pass the attribute to the low level sysdev show/store function

2008-07-21 21:55:02 -07:00

rtmutex.c

hrtimer: convert kernel/* to the new hrtimer apis

2008-09-05 21:35:13 -07:00

rtmutex.h

…

rwsem.c

…

sched_clock.c

Merge branch 'tracing/core-v2' into tracing-for-linus

2009-04-02 00:49:02 +02:00

sched_cpupri.c

sched_rt: don't allocate cpumask in fastpath

2009-04-01 13:24:51 +02:00

sched_cpupri.h

cpumask: remove cpumask_t from core

2009-03-30 22:05:17 +10:30

sched_debug.c

sched: remove unused fields from struct rq

2009-03-24 23:16:51 +01:00

sched_fair.c

Merge branch 'sched/urgent'; commit 'v2.6.29-rc5' into sched/core

2009-02-15 21:15:16 +01:00

sched_features.h

Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-03-30 17:17:35 -07:00

sched_idletask.c

sched: add CONFIG_SMP consistency

2008-10-22 10:01:52 +02:00

sched_rt.c

Merge commit 'v2.6.30-rc1' into sched/urgent

2009-04-08 17:26:00 +02:00

sched_stats.h

sched: remove unused fields from struct rq

2009-03-24 23:16:51 +01:00

sched.c

Merge commit 'v2.6.30-rc1' into sched/urgent

2009-04-08 17:26:00 +02:00

seccomp.c

x86-64: seccomp: fix 32/64 syscall hole

2009-03-02 15:41:30 -08:00

semaphore.c

semaphore: __down_common: use signal_pending_state()

2008-08-05 14:33:47 -07:00

signal.c

signals: SI_USER: Masquerade si_pid when crossing pid ns boundary

2009-04-02 19:04:58 -07:00

slow-work.c

Document the slow work thread pool

2009-04-03 16:42:35 +01:00

smp.c

generic-ipi: eliminate WARN_ON()s during oops/panic

2009-03-13 10:47:34 +01:00

softirq.c

Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-06 13:37:30 -07:00

softlockup.c

softlockup: decouple hung tasks check from softlockup detection

2009-01-16 14:06:04 +01:00

spinlock.c

Allow rwlocks to re-enable interrupts

2009-04-02 19:05:11 -07:00

srcu.c

make srcu_readers_active() static

2008-02-06 10:41:02 -08:00

stacktrace.c

stacktrace: provide save_stack_trace_tsk() weak alias

2008-12-25 11:44:43 +01:00

stop_machine.c

cpumask: remove cpumask_t from core

2009-03-30 22:05:17 +10:30

sys_ni.c

[CVE-2009-0029] Make sys_syslog a conditional system call

2009-01-14 14:15:16 +01:00

sys.c

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2009-04-02 21:09:10 -07:00

sysctl_check.c

net: add ARP notify option for devices

2009-02-01 01:04:33 -08:00

sysctl.c

Merge branch 'core/softlockup' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-07 14:11:07 -07:00

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

Make constants in kernel/timeconst.h fixed 64 bits

2008-05-02 16:18:42 -07:00

timer.c

Merge branches 'core-fixes-for-linus', 'irq-fixes-for-linus' and 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-04-09 10:35:30 -07:00

tracepoint.c

tracepoints: dont update zero-sized tracepoint sections

2009-03-18 19:55:00 +01:00

tsacct.c

Fix fixpoint divide exception in acct_update_integrals

2009-03-09 08:13:35 -07:00

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_namespace.c

Fix recursive lock in free_uid()/free_user_ns()

2009-02-27 16:26:21 -08:00

user.c

Merge branch 'master' into next

2009-03-24 10:52:46 +11:00

utsname_sysctl.c

proc_sysctl: use CONFIG_PROC_SYSCTL around ipc and utsname proc_handlers

2009-04-02 19:05:01 -07:00

utsname.c

removed unused #include <linux/version.h>'s

2008-08-23 12:14:12 -07:00

wait.c

wait: prevent exclusive waiter starvation

2009-02-05 12:56:48 -08:00

workqueue.c

work_on_cpu(): rewrite it to create a kernel thread on demand

2009-04-09 09:50:37 +09:30