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Eric B Munson 7f310a5d4e perf_event: Fix broken calc_timer_values() 
We detected a serious issue with PERF_SAMPLE_READ and
timing information when events were being multiplexing.

Samples would have time_running > time_enabled. That
was easy to reproduce with a libpfm4 example (ran 3
times to cause multiplexing on Core 2):

 $ syst_smpl -e uops_retired:freq=1 &
 $ syst_smpl -e uops_retired:freq=1 &
 $ syst_smpl -e uops_retired:freq=1 &
 IIP:0x0000000040062d ... PERIOD:2355332948 ENA=40144625315 RUN=60014875184
 syst_smpl: WARNING: time_running > time_enabled
	63277537998 uops_retired:freq=1 , scaled

The bug was not present in kernel up to (and including) 3.0. It turns
out the bug was introduced by the following commit:

commit c4794295917ebeda8013b6cb9c8d71ab4f74a1fa

    events: Move lockless timer calculation into helper function

The parameters of the function got reversed yet the call sites
were not updated to reflect the change. That lead to time_running
and time_enabled being swapped. That had no effect when there was
no multiplexing because in that case time_running = time_enabled
but it would show up in any other scenario.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110829124112.GA4828@quad
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-31 15:56:29 +02:00
..
debug
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
2011-08-01 13:39:40 -10:00
events
perf_event: Fix broken calc_timer_values()
2011-08-31 15:56:29 +02:00
gcov
gcov: disable CONSTRUCTORS for UML
2011-07-26 16:49:45 -07:00
irq
Revert "irq: Always set IRQF_ONESHOT if no primary handler is specified"
2011-08-23 10:36:51 -07:00
power
PM / Domains: Fix build for CONFIG_PM_RUNTIME unset
2011-08-14 13:34:31 +02:00
time
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-07-22 16:52:18 -07:00
trace
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
2011-08-19 10:47:07 -07:00
.gitignore
…
acct.c
pass a struct path to vfs_statfs
2010-08-09 16:48:42 -04:00
async.c
async: Fixed an include coding style issue
2011-06-14 22:48:46 -04:00
audit_tree.c
audit_tree,rcu: Convert call_rcu(__put_tree) to kfree_rcu()
2011-07-20 14:10:11 -07:00
audit_watch.c
kill path_lookup()
2011-03-14 09:15:23 -04:00
audit.c
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
audit.h
audit: make functions static
2010-10-30 01:42:19 -04:00
auditfilter.c
netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms
2011-03-03 10:55:40 -08:00
auditsc.c
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
backtracetest.c
…
bounds.c
memcg: remove direct page_cgroup-to-page pointer
2011-03-23 19:46:28 -07:00
capability.c
Merge branch 'master' into next
2011-05-19 18:51:57 +10:00
cgroup_freezer.c
cgroups: add per-thread subsystem callbacks
2011-05-26 17:12:34 -07:00
cgroup.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
2011-07-27 19:26:38 -07:00
compat.c
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6
2011-07-30 00:08:53 -07:00
configs.c
kernel/configs.c: include MODULE_*() when CONFIG_IKCONFIG_PROC=n
2011-07-25 20:57:15 -07:00
cpu.c
Fix common misspellings
2011-03-31 11:26:23 -03:00
cpuset.c
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
crash_dump.c
crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn
2011-03-23 19:47:19 -07:00
cred.c
move RLIMIT_NPROC check from set_user() to do_execve_common()
2011-08-11 11:24:42 -07:00
delayacct.c
KVM: Steal time implementation
2011-07-14 12:59:14 +03:00
dma.c
…
elfcore.c
elf coredump: add extended numbering support
2010-03-06 11:26:46 -08:00
exec_domain.c
sys_personality: remove the bogus checks in sys_personality()->__set_personality() path
2010-08-09 20:45:05 -07:00
exit.c
ipc: introduce shm_rmid_forced sysctl
2011-07-26 16:49:44 -07:00
extable.c
extable, core_kernel_data(): Make sure all archs define _sdata
2011-05-20 08:56:56 +02:00
fork.c
move RLIMIT_NPROC check from set_user() to do_execve_common()
2011-08-11 11:24:42 -07:00
freezer.c
Freezer: Use SMP barriers
2011-05-17 23:19:17 +02:00
futex_compat.c
userns: user namespaces: convert several capable() calls
2011-03-23 19:47:08 -07:00
futex.c
Merge branch 'linus' into core/urgent
2011-08-04 09:09:27 +02:00
groups.c
userns: user namespaces: convert several capable() calls
2011-03-23 19:47:08 -07:00
hrtimer.c
hrtimers: Fix typo causing erratic timers
2011-05-25 15:31:58 -07:00
hung_task.c
watchdog, hung_task_timeout: Add Kconfig configurable default
2011-04-28 09:13:17 +02:00
irq_work.c
irq_work: Use per cpu atomics instead of regular atomics
2010-12-18 15:54:48 +01:00
itimer.c
…
jump_label.c
jump_label: Fix jump_label update for modules
2011-06-29 09:59:17 -04:00
kallsyms.c
Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-03-25 17:52:22 -07:00
Kconfig.freezer
…
Kconfig.hz
…
Kconfig.locks
arch:Kconfig.locks Remove unused config option.
2011-04-10 17:01:05 +02:00
Kconfig.preempt
sched: Isolate preempt counting in its own config option
2011-06-10 15:15:40 +02:00
kexec.c
treewide: Convert uses of struct resource to resource_size(ptr)
2011-06-10 14:55:36 +02:00
kfifo.c
kfifo: fix scatterlist usage
2010-10-01 10:50:58 -07:00
kmod.c
Boot up with usermodehelper disabled
2011-08-03 22:03:29 -10:00
kprobes.c
kprobes: Return -ENOENT if probe point doesn't exist
2011-07-15 15:11:47 -04:00
ksysfs.c
kernel/ksysfs.c: expose file_caps_enabled in sysfs
2011-04-19 16:45:51 -07:00
kthread.c
cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed
2011-05-28 17:02:57 +02:00
latencytop.c
Fix common misspellings
2011-03-31 11:26:23 -03:00
lockdep_internals.h
lockdep: No need to disable preemption in debug atomic ops
2010-05-04 05:38:16 +02:00
lockdep_proc.c
lockdep: Remove unused 'factor' variable from lockdep_stats_show()
2011-03-23 13:54:47 +01:00
lockdep_states.h
…
lockdep.c
lockdep: Fix wrong assumption in match_held_lock
2011-08-09 11:57:35 +02:00
Makefile
jump label: Reduce the cycle count by changing the link order
2011-08-05 23:57:33 +02:00
module.c
module: add /sys/module/<name>/uevent files
2011-07-24 22:06:04 +09:30
mutex-debug.c
mutex: Use p->on_cpu for the adaptive spin
2011-04-14 08:52:33 +02:00
mutex-debug.h
mutex: Use p->on_cpu for the adaptive spin
2011-04-14 08:52:33 +02:00
mutex.c
lockdep, mutex: provide mutex_lock_nest_lock
2011-05-25 08:39:17 -07:00
mutex.h
mutex: Use p->on_cpu for the adaptive spin
2011-04-14 08:52:33 +02:00
notifier.c
notifiers: sys: move reboot notifiers into reboot.h
2011-07-25 20:57:14 -07:00
nsproxy.c
make sure that nsproxy_cache is initialized early enough
2011-07-20 01:44:07 -04:00
padata.c
Fix common misspellings
2011-03-31 11:26:23 -03:00
panic.c
panic: panic=-1 for immediate reboot
2011-07-26 16:49:45 -07:00
params.c
module: add /sys/module/<name>/uevent files
2011-07-24 22:06:04 +09:30
pid_namespace.c
pidns: call pid_ns_prepare_proc() from create_pid_namespace()
2011-03-23 19:46:58 -07:00
pid.c
rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
2011-07-08 22:21:58 +02:00
pm_qos_params.c
plist: Remove the need to supply locks to plist heads
2011-07-08 14:02:53 +02:00
posix-cpu-timers.c
hrtimers: Avoid touching inactive timer bases
2011-05-23 13:59:54 +02:00
posix-timers.c
posix-timers: RCU conversion
2011-05-24 12:10:51 +02:00
printk.c
kernel/printk: do not turn off bootconsole in printk_late_init() if keep_bootcon
2011-08-25 16:25:34 -07:00
profile.c
kernel/profile.c: remove some duplicate code from profile_hits()
2011-05-26 17:12:37 -07:00
ptrace.c
connector: add an event for monitoring process tracers
2011-07-18 21:38:33 +02:00
range.c
kernel/range.c: fix clean_sort_range() for the case of full array
2010-11-12 07:55:31 -08:00
rcupdate.c
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
rcutiny_plugin.h
rcu: Converge TINY_RCU expedited and normal boosting
2011-05-05 23:16:58 -07:00
rcutiny.c
sanitize <linux/prefetch.h> usage
2011-05-20 12:50:29 -07:00
rcutorture.c
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
rcutree_plugin.h
softirq,rcu: Inform RCU of irq_exit() activity
2011-07-20 10:50:12 -07:00
rcutree_trace.c
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
rcutree.c
rcu: Prevent RCU callbacks from executing before scheduler initialized
2011-07-13 08:17:56 -07:00
rcutree.h
rcu: Move RCU_BOOST #ifdefs to header file
2011-06-16 16:12:05 -07:00
relay.c
Clean up relay_alloc_page_array() slightly by using vzalloc rather than vmalloc and memset
2010-11-05 08:21:34 -07:00
res_counter.c
memcg: res_counter_read_u64(): fix potential races on 32-bit machines
2011-03-23 19:46:22 -07:00
resource.c
resources: Add lookup_resource()
2011-07-30 21:21:39 +02:00
rtmutex_common.h
rtmutex: Simplify PI algorithm and make highest prio task get lock
2011-01-27 21:13:51 -05:00
rtmutex-debug.c
rtmutex: Simplify PI algorithm and make highest prio task get lock
2011-01-27 21:13:51 -05:00
rtmutex-debug.h
…
rtmutex-tester.c
rtmutex: tester: Remove the remaining BKL leftovers
2011-02-22 22:07:22 +01:00
rtmutex.c
plist: Remove the need to supply locks to plist heads
2011-07-08 14:02:53 +02:00
rtmutex.h
…
rwsem.c
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
sched_autogroup.c
Fix common misspellings
2011-03-31 11:26:23 -03:00
sched_autogroup.h
sched: Skip autogroup when looking for all rt sched groups
2011-07-01 10:39:08 +02:00
sched_clock.c
sched: Add some clock info to sched_debug
2010-11-23 10:29:08 +01:00
sched_cpupri.c
sched: No need for bootmem special cases
2010-07-17 12:06:22 +02:00
sched_cpupri.h
sched: No need for bootmem special cases
2010-07-17 12:06:22 +02:00
sched_debug.c
sched: Get rid of lock_depth
2011-04-24 13:18:38 +02:00
sched_fair.c
sched: Cleanup duplicate local variable in [enqueue|dequeue]_task_fair
2011-07-22 12:47:22 +02:00
sched_features.h
Merge branch 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
2011-07-24 09:07:03 -07:00
sched_idletask.c
sched: Drop the rq argument to sched_class::select_task_rq()
2011-04-14 08:52:36 +02:00
sched_rt.c
sched: Skip autogroup when looking for all rt sched groups
2011-07-01 10:39:08 +02:00
sched_stats.h
sched: More sched_domain iterations fixes
2011-05-28 17:02:54 +02:00
sched_stoptask.c
sched: Drop the rq argument to sched_class::select_task_rq()
2011-04-14 08:52:36 +02:00
sched.c
perf events: Fix slow and broken cgroup context switch code
2011-08-29 12:28:33 +02:00
seccomp.c
…
semaphore.c
…
signal.c
signals: sys_ssetmask/sys_rt_sigsuspend should use set_current_blocked()
2011-07-27 12:53:36 -07:00
smp.c
generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts
2011-06-17 10:17:12 +02:00
softirq.c
softirq,rcu: Inform RCU of irq_exit() activity
2011-07-20 10:50:12 -07:00
spinlock.c
locking: Cleanup the name space completely
2009-12-14 23:55:33 +01:00
srcu.c
rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status
2011-01-14 04:56:49 -08:00
stacktrace.c
stack_trace: Add weak save_stack_trace_regs()
2011-06-14 22:48:52 -04:00
stop_machine.c
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
sys_ni.c
All Arch: remove linkage for sys_nfsservctl system call
2011-08-26 15:09:58 -07:00
sys.c
Add a personality to report 2.6.x version numbers
2011-08-25 10:17:28 -07:00
sysctl_binary.c
xfs: remove subdirectories
2011-08-12 16:21:35 -05:00
sysctl_check.c
xfs: remove subdirectories
2011-08-12 16:21:35 -05:00
sysctl.c
sysctl,rcu: Convert call_rcu(free_head) to kfree
2011-07-20 14:10:18 -07:00
taskstats.c
taskstats: add_del_listener() should ignore !valid listeners
2011-08-03 14:25:20 -10:00
test_kprobes.c
kprobes: Fix selftest to clear flags field for reusing probes
2010-10-14 08:55:27 +02:00
time.c
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-03-15 18:53:35 -07:00
timeconst.pl
…
timer.c
timers: Consider slack value in mod_timer()
2011-06-03 15:02:32 +02:00
tracepoint.c
jump label: Introduce static_branch() interface
2011-04-04 12:48:08 -04:00
tsacct.c
taskstats: use real microsecond granularity for CPU times
2010-10-27 18:03:17 -07:00
uid16.c
userns: user namespaces: convert several capable() calls
2011-03-23 19:47:08 -07:00
up.c
…
user_namespace.c
user_ns: improve the user_ns on-the-slab packaging
2011-01-13 08:03:18 -08:00
user-return-notifier.c
Fix common misspellings
2011-03-31 11:26:23 -03:00
user.c
userns: add a user_namespace as creator/owner of uts_namespace
2011-03-23 19:46:59 -07:00
utsname_sysctl.c
…
utsname.c
ns proc: Add support for the uts namespace
2011-05-10 14:35:35 -07:00
wait.c
Fix common misspellings
2011-03-31 11:26:23 -03:00
watchdog.c
perf, x86: P4 PMU - Introduce event alias feature
2011-07-14 17:25:04 -04:00
workqueue_sched.h
workqueue: implement concurrency managed dynamic worker pool
2010-06-29 10:07:14 +02:00
workqueue.c
Merge branch 'for-3.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2011-07-22 15:07:15 -07:00