mirror of https://gitee.com/openkylin/linux.git
[S390] extend virtual timer interface by mod_virt_timer_periodic
In case mod_virt_timer is used to add a non pending timer the timer is always added as a one-shot timer. If mod_virt_timer is used for periodic timers they may therfore be degraded to one-shot timers. Add mod_virt_timer_periodic to the interface to allow safe re-programming of the interval value. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
parent
0436230148
commit
b6ecfa9273
|
@ -41,6 +41,7 @@ extern void init_virt_timer(struct vtimer_list *timer);
|
|||
extern void add_virt_timer(void *new);
|
||||
extern void add_virt_timer_periodic(void *new);
|
||||
extern int mod_virt_timer(struct vtimer_list *timer, __u64 expires);
|
||||
extern int mod_virt_timer_periodic(struct vtimer_list *timer, __u64 expires);
|
||||
extern int del_virt_timer(struct vtimer_list *timer);
|
||||
|
||||
extern void init_cpu_vtimer(void);
|
||||
|
|
|
@ -425,17 +425,7 @@ void add_virt_timer_periodic(void *new)
|
|||
}
|
||||
EXPORT_SYMBOL(add_virt_timer_periodic);
|
||||
|
||||
/*
|
||||
* If we change a pending timer the function must be called on the CPU
|
||||
* where the timer is running on, e.g. by smp_call_function_single()
|
||||
*
|
||||
* The original mod_timer adds the timer if it is not pending. For
|
||||
* compatibility we do the same. The timer will be added on the current
|
||||
* CPU as a oneshot timer.
|
||||
*
|
||||
* returns whether it has modified a pending timer (1) or not (0)
|
||||
*/
|
||||
int mod_virt_timer(struct vtimer_list *timer, __u64 expires)
|
||||
int __mod_vtimer(struct vtimer_list *timer, __u64 expires, int periodic)
|
||||
{
|
||||
struct vtimer_queue *vq;
|
||||
unsigned long flags;
|
||||
|
@ -444,39 +434,35 @@ int mod_virt_timer(struct vtimer_list *timer, __u64 expires)
|
|||
BUG_ON(!timer->function);
|
||||
BUG_ON(!expires || expires > VTIMER_MAX_SLICE);
|
||||
|
||||
/*
|
||||
* This is a common optimization triggered by the
|
||||
* networking code - if the timer is re-modified
|
||||
* to be the same thing then just return:
|
||||
*/
|
||||
if (timer->expires == expires && vtimer_pending(timer))
|
||||
return 1;
|
||||
|
||||
cpu = get_cpu();
|
||||
vq = &per_cpu(virt_cpu_timer, cpu);
|
||||
|
||||
/* check if we run on the right CPU */
|
||||
BUG_ON(timer->cpu != cpu);
|
||||
|
||||
/* disable interrupts before test if timer is pending */
|
||||
spin_lock_irqsave(&vq->lock, flags);
|
||||
|
||||
/* if timer isn't pending add it on the current CPU */
|
||||
if (!vtimer_pending(timer)) {
|
||||
spin_unlock_irqrestore(&vq->lock, flags);
|
||||
/* we do not activate an interval timer with mod_virt_timer */
|
||||
timer->interval = 0;
|
||||
|
||||
if (periodic)
|
||||
timer->interval = expires;
|
||||
else
|
||||
timer->interval = 0;
|
||||
timer->expires = expires;
|
||||
timer->cpu = cpu;
|
||||
internal_add_vtimer(timer);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* check if we run on the right CPU */
|
||||
BUG_ON(timer->cpu != cpu);
|
||||
|
||||
list_del_init(&timer->entry);
|
||||
timer->expires = expires;
|
||||
|
||||
/* also change the interval if we have an interval timer */
|
||||
if (timer->interval)
|
||||
if (periodic)
|
||||
timer->interval = expires;
|
||||
|
||||
/* the timer can't expire anymore so we can release the lock */
|
||||
|
@ -484,8 +470,31 @@ int mod_virt_timer(struct vtimer_list *timer, __u64 expires)
|
|||
internal_add_vtimer(timer);
|
||||
return 1;
|
||||
}
|
||||
|
||||
/*
|
||||
* If we change a pending timer the function must be called on the CPU
|
||||
* where the timer is running on.
|
||||
*
|
||||
* returns whether it has modified a pending timer (1) or not (0)
|
||||
*/
|
||||
int mod_virt_timer(struct vtimer_list *timer, __u64 expires)
|
||||
{
|
||||
return __mod_vtimer(timer, expires, 0);
|
||||
}
|
||||
EXPORT_SYMBOL(mod_virt_timer);
|
||||
|
||||
/*
|
||||
* If we change a pending timer the function must be called on the CPU
|
||||
* where the timer is running on.
|
||||
*
|
||||
* returns whether it has modified a pending timer (1) or not (0)
|
||||
*/
|
||||
int mod_virt_timer_periodic(struct vtimer_list *timer, __u64 expires)
|
||||
{
|
||||
return __mod_vtimer(timer, expires, 1);
|
||||
}
|
||||
EXPORT_SYMBOL(mod_virt_timer_periodic);
|
||||
|
||||
/*
|
||||
* delete a virtual timer
|
||||
*
|
||||
|
|
Loading…
Reference in New Issue