5e41d0d60a
Taking a cpu offline removes the cpu from the online mask before the CPU_DEAD notification is done. The clock events layer does the cleanup of the dead CPU from the CPU_DEAD notifier chain. tick_do_timer_cpu is used to avoid xtime lock contention by assigning the task of jiffies xtime updates to one CPU. If a CPU is taken offline, then this assignment becomes stale. This went unnoticed because most of the time the offline CPU went dead before the online CPU reached __cpu_die(), where the CPU_DEAD state is checked. In the case that the offline CPU did not reach the DEAD state before we reach __cpu_die(), the code in there goes to sleep for 100ms. Due to the stale time update assignment, the system is stuck forever. Take the assignment away when a cpu is not longer in the cpu_online_mask. We do this in the last call to tick_nohz_stop_sched_tick() when the offline CPU is on the way to the final play_dead() idle entry. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
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.. | ||
irq | ||
power | ||
time | ||
.gitignore | ||
acct.c | ||
audit.c | ||
audit.h | ||
auditfilter.c | ||
auditsc.c | ||
capability.c | ||
compat.c | ||
configs.c | ||
cpu.c | ||
cpuset.c | ||
delayacct.c | ||
die_notifier.c | ||
dma.c | ||
exec_domain.c | ||
exit.c | ||
extable.c | ||
fork.c | ||
futex_compat.c | ||
futex.c | ||
hrtimer.c | ||
itimer.c | ||
kallsyms.c | ||
Kconfig.hz | ||
Kconfig.preempt | ||
kexec.c | ||
kfifo.c | ||
kmod.c | ||
kprobes.c | ||
ksysfs.c | ||
kthread.c | ||
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 | ||
panic.c | ||
params.c | ||
pid.c | ||
posix-cpu-timers.c | ||
posix-timers.c | ||
printk.c | ||
profile.c | ||
ptrace.c | ||
rcupdate.c | ||
rcutorture.c | ||
relay.c | ||
resource.c | ||
rtmutex_common.h | ||
rtmutex-debug.c | ||
rtmutex-debug.h | ||
rtmutex-tester.c | ||
rtmutex.c | ||
rtmutex.h | ||
rwsem.c | ||
sched_debug.c | ||
sched_fair.c | ||
sched_idletask.c | ||
sched_rt.c | ||
sched_stats.h | ||
sched.c | ||
seccomp.c | ||
signal.c | ||
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 | ||
tsacct.c | ||
uid16.c | ||
user_namespace.c | ||
user.c | ||
utsname_sysctl.c | ||
utsname.c | ||
wait.c | ||
workqueue.c |