kernel-ark/kernel
Thomas Gleixner 746976a301 NTP: remove clock_was_set() call to prevent deadlock
The clock_was_set() call in seconds_overflow() which happens only when
leap seconds are inserted / deleted is wrong in two aspects:

1. it results in a call to on_each_cpu() with interrupts disabled
2. it is potential deadlock source vs. call_lock in smp_call_function()

The only possible side effect of the removal might be, that an absolute
CLOCK_REALTIME timer fires 1 second too late, in the rare case of leap
second deletion and an absolute CLOCK_REALTIME timer which expires in
the affected time frame. It will never fire too early.

This was probably observed by the reporter of a June 30th -> July 1st
hang: http://lkml.org/lkml/2007/7/3/103

A similar problem was observed by Dave Jones, who provided a screen shot
with a lockdep back trace, which allowed to analyse the problem.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-03 13:54:27 -07:00
..
irq Fix crash with irqpoll due to the IRQF_IRQPOLL flag testing 2007-05-24 08:37:14 -07:00
power PM: introduce set_target method in pm_ops 2007-07-01 12:29:44 -07:00
time NTP: remove clock_was_set() call to prevent deadlock 2007-07-03 13:54:27 -07:00
.gitignore
acct.c
audit.c
audit.h
auditfilter.c audit: fix oops removing watch if audit disabled 2007-06-24 08:59:12 -07:00
auditsc.c
capability.c
compat.c
configs.c
cpu.c
cpuset.c cpuset: zero malloc - fix for old cpusets 2007-06-16 13:16:15 -07:00
delayacct.c
die_notifier.c
dma.c
exec_domain.c
exit.c pi-futex: fix exit races and locking problems 2007-06-08 17:23:34 -07:00
extable.c
fork.c freezer: fix vfork problem 2007-05-23 20:14:11 -07:00
futex_compat.c Revert "futex_requeue_pi optimization" 2007-06-18 09:48:41 -07:00
futex.c FUTEX: Restore the dropped ERSCH fix 2007-06-24 12:08:53 -07:00
hrtimer.c
itimer.c
kallsyms.c fix possible null ptr deref in kallsyms_lookup 2007-05-30 10:51:38 -07:00
Kconfig.hz
Kconfig.preempt
kexec.c
kfifo.c
kmod.c
kprobes.c
ksysfs.c
kthread.c freezer: fix kthread_create vs freezer theoretical race 2007-05-23 20:14:11 -07:00
latency.c
lockdep_internals.h
lockdep_proc.c
lockdep.c
Makefile
module.c
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
nsproxy.c fix refcounting of nsproxy object when unshared 2007-06-24 08:59:10 -07:00
panic.c
params.c
pid.c
posix-cpu-timers.c
posix-timers.c posix-timers: Prevent softirq starvation by small intervals and SIG_IGN 2007-06-21 15:57:04 -07:00
printk.c
profile.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
ptrace.c
rcupdate.c
rcutorture.c
relay.c relayfs: fix overwrites 2007-06-28 11:38:18 -07:00
resource.c
rtmutex_common.h Revert "futex_requeue_pi optimization" 2007-06-18 09:48:41 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c Revert "futex_requeue_pi optimization" 2007-06-18 09:48:41 -07:00
rtmutex.h
rwsem.c
sched.c sched: fix next_interval determination in idle_balance() 2007-06-24 08:59:11 -07:00
seccomp.c
signal.c Fix signalfd interaction with thread-private signals 2007-06-18 10:18:32 -07:00
softirq.c
softlockup.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c
sysctl.c
taskstats.c
time.c
timer.c NOHZ: prevent multiplication overflow - stop timer for huge timeouts 2007-05-29 18:11:10 -07:00
tsacct.c
uid16.c
user.c
utsname_sysctl.c
utsname.c
wait.c
workqueue.c simplify cleanup_workqueue_thread() 2007-05-23 20:14:13 -07:00