From b6ecfa9273e27b5c7ba04655eb44f78bf4db5b64 Mon Sep 17 00:00:00 2001 From: Jan Glauber Date: Tue, 14 Apr 2009 15:36:20 +0200 Subject: [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 Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/vtime.c | 57 ++++++++++++++++++++++++++++-------------------- 1 file changed, 33 insertions(+), 24 deletions(-) (limited to 'arch/s390/kernel/vtime.c') diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index ecf0304..694b443 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -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 */ @@ -484,9 +470,32 @@ 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 * * returns whether the deleted timer was pending (1) or not (0) -- cgit v1.1 From b86ccca49cd8f22086c1d135ab3051cf48fb1688 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 14 Apr 2009 15:36:26 +0200 Subject: [S390] fix idle time accounting The steal time is calculated by subtracting the time the virtual cpu has been running on a physical cpu from the wall clock time. To make that work all wall time needs to be added to the steal time field first before the virtual cpu time is subtracted. The time between the last clock update and the load of the enabled wait psw needs to be added to the steal_time field as well to make the sum over all cpu accounting numbers match the wall clock. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/vtime.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/s390/kernel/vtime.c') diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index 694b443..c0870a6 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -134,6 +134,8 @@ void vtime_start_cpu(void) /* Account time spent with enabled wait psw loaded as idle time. */ idle_time = S390_lowcore.int_clock - idle->idle_enter; account_idle_time(idle_time); + S390_lowcore.steal_timer += + idle->idle_enter - S390_lowcore.last_update_clock; S390_lowcore.last_update_clock = S390_lowcore.int_clock; /* Account system time spent going idle. */ -- cgit v1.1 From ab96e798cbd562a53edd802272e49a5100b29efb Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 14 Apr 2009 15:36:29 +0200 Subject: [S390] boot cputime accounting Start the cpu time accounting very early to catch the cpu time spent for the initial kernel setup. To make the output of /proc/uptime match the sum of all cpu accounting values of the boot cpu reset xtime and wall_to_monotonic to sane values based on the TOD clock. The values set by timekeeping_init are off by up to a second. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/vtime.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'arch/s390/kernel/vtime.c') diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index c0870a6..38ea92f 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -527,16 +527,8 @@ EXPORT_SYMBOL(del_virt_timer); */ void init_cpu_vtimer(void) { - struct thread_info *ti = current_thread_info(); struct vtimer_queue *vq; - S390_lowcore.user_timer = ti->user_timer; - S390_lowcore.system_timer = ti->system_timer; - - /* kick the virtual timer */ - asm volatile ("STCK %0" : "=m" (S390_lowcore.last_update_clock)); - asm volatile ("STPT %0" : "=m" (S390_lowcore.last_update_timer)); - /* initialize per cpu vtimer structure */ vq = &__get_cpu_var(virt_cpu_timer); INIT_LIST_HEAD(&vq->list); -- cgit v1.1 From e1c805309d19c69d4ebeac38724076fa86feacdf Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 23 Apr 2009 13:58:08 +0200 Subject: [S390] /proc/stat idle field for idle cpus The cpu idle field in the output of /proc/stat is too small for cpus that have been idle for more than a tick. Add the architecture hook arch_idle_time that allows to add the not accounted idle time of a sleeping cpu without waking the cpu. The s390 implementation of arch_idle_time uses the already existing s390_idle_data per_cpu variable to find the sleep time of a neighboring idle cpu. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/vtime.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'arch/s390/kernel/vtime.c') diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index 38ea92f..c87f59b 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -240,6 +240,22 @@ void vtime_stop_cpu(void) } } +cputime64_t s390_get_idle_time(int cpu) +{ + struct s390_idle_data *idle; + unsigned long long now, idle_time, idle_enter; + + idle = &per_cpu(s390_idle, cpu); + spin_lock(&idle->lock); + now = get_clock(); + idle_time = 0; + idle_enter = idle->idle_enter; + if (idle_enter != 0ULL && idle_enter < now) + idle_time = now - idle_enter; + spin_unlock(&idle->lock); + return idle_time; +} + /* * Sorted add to a list. List is linear searched until first bigger * element is found. -- cgit v1.1