X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;ds=sidebyside;f=kernel%2Ftimer.c;h=1d7dd6267c2de52206bb2f09ca981ff81db4b1a1;hb=6e936d3e9a45a4307e7f4a29ee9829e7a0464af1;hp=2a87430a58d4046d10000fcd6bd4e56308a9a4bc;hpb=826adfe49a508f15943ce9140a3fc7f6c7661509;p=powerpc.git diff --git a/kernel/timer.c b/kernel/timer.c index 2a87430a58..1d7dd6267c 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -84,7 +84,7 @@ typedef struct tvec_t_base_s tvec_base_t; tvec_base_t boot_tvec_bases; EXPORT_SYMBOL(boot_tvec_bases); -static DEFINE_PER_CPU(tvec_base_t *, tvec_bases) = { &boot_tvec_bases }; +static DEFINE_PER_CPU(tvec_base_t *, tvec_bases) = &boot_tvec_bases; static inline void set_running_timer(tvec_base_t *base, struct timer_list *timer) @@ -374,6 +374,7 @@ int del_timer_sync(struct timer_list *timer) int ret = try_to_del_timer_sync(timer); if (ret >= 0) return ret; + cpu_relax(); } } @@ -407,7 +408,7 @@ static int cascade(tvec_base_t *base, tvec_t *tv, int index) * This function cascades all vectors and executes all expired timer * vectors. */ -#define INDEX(N) (base->timer_jiffies >> (TVR_BITS + N * TVN_BITS)) & TVN_MASK +#define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK) static inline void __run_timers(tvec_base_t *base) { @@ -968,6 +969,7 @@ void __init timekeeping_init(void) } +static int timekeeping_suspended; /* * timekeeping_resume - Resumes the generic timekeeping subsystem. * @dev: unused @@ -983,6 +985,18 @@ static int timekeeping_resume(struct sys_device *dev) write_seqlock_irqsave(&xtime_lock, flags); /* restart the last cycle value */ clock->cycle_last = clocksource_read(clock); + clock->error = 0; + timekeeping_suspended = 0; + write_sequnlock_irqrestore(&xtime_lock, flags); + return 0; +} + +static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) +{ + unsigned long flags; + + write_seqlock_irqsave(&xtime_lock, flags); + timekeeping_suspended = 1; write_sequnlock_irqrestore(&xtime_lock, flags); return 0; } @@ -990,6 +1004,7 @@ static int timekeeping_resume(struct sys_device *dev) /* sysfs resume/suspend bits for timekeeping */ static struct sysdev_class timekeeping_sysclass = { .resume = timekeeping_resume, + .suspend = timekeeping_suspend, set_kset_name("timekeeping"), }; @@ -1100,13 +1115,16 @@ static void update_wall_time(void) { cycle_t offset; - clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift; + /* Make sure we're fully resumed: */ + if (unlikely(timekeeping_suspended)) + return; #ifdef CONFIG_GENERIC_TIME offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask; #else offset = clock->cycle_interval; #endif + clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift; /* normally this loop will run just once, however in the * case of lost or late ticks, it will accumulate correctly. @@ -1306,46 +1324,19 @@ asmlinkage long sys_getpid(void) } /* - * Accessing ->group_leader->real_parent is not SMP-safe, it could - * change from under us. However, rather than getting any lock - * we can use an optimistic algorithm: get the parent - * pid, and go back and check that the parent is still - * the same. If it has changed (which is extremely unlikely - * indeed), we just try again.. - * - * NOTE! This depends on the fact that even if we _do_ - * get an old value of "parent", we can happily dereference - * the pointer (it was and remains a dereferencable kernel pointer - * no matter what): we just can't necessarily trust the result - * until we know that the parent pointer is valid. - * - * NOTE2: ->group_leader never changes from under us. + * Accessing ->real_parent is not SMP-safe, it could + * change from under us. However, we can use a stale + * value of ->real_parent under rcu_read_lock(), see + * release_task()->call_rcu(delayed_put_task_struct). */ asmlinkage long sys_getppid(void) { int pid; - struct task_struct *me = current; - struct task_struct *parent; - parent = me->group_leader->real_parent; - for (;;) { - pid = parent->tgid; -#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) -{ - struct task_struct *old = parent; + rcu_read_lock(); + pid = rcu_dereference(current->real_parent)->tgid; + rcu_read_unlock(); - /* - * Make sure we read the pid before re-reading the - * parent pointer: - */ - smp_rmb(); - parent = me->group_leader->real_parent; - if (old != parent) - continue; -} -#endif - break; - } return pid; } @@ -1670,7 +1661,7 @@ static void __devinit migrate_timers(int cpu) } #endif /* CONFIG_HOTPLUG_CPU */ -static int __devinit timer_cpu_notify(struct notifier_block *self, +static int __cpuinit timer_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { long cpu = (long)hcpu; @@ -1690,7 +1681,7 @@ static int __devinit timer_cpu_notify(struct notifier_block *self, return NOTIFY_OK; } -static struct notifier_block __devinitdata timers_nb = { +static struct notifier_block __cpuinitdata timers_nb = { .notifier_call = timer_cpu_notify, };