Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  time: Fix accumulation bug triggered by long delay.
  posix-cpu-timers: Reset expire cache when no timer is running
  timer stats: Fix del_timer_sync() and try_to_del_timer_sync()
  clockevents: Sanitize min_delta_ns adjustment and prevent overflows
This commit is contained in:
Linus Torvalds 2010-03-26 15:10:38 -07:00
commit 054319b5e2
6 changed files with 54 additions and 17 deletions

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@ -73,6 +73,7 @@ enum clock_event_nofitiers {
* @list: list head for the management code
* @mode: operating mode assigned by the management code
* @next_event: local storage for the next event in oneshot mode
* @retries: number of forced programming retries
*/
struct clock_event_device {
const char *name;
@ -93,6 +94,7 @@ struct clock_event_device {
struct list_head list;
enum clock_event_mode mode;
ktime_t next_event;
unsigned long retries;
};
/*

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@ -1061,9 +1061,9 @@ static void check_thread_timers(struct task_struct *tsk,
}
}
static void stop_process_timers(struct task_struct *tsk)
static void stop_process_timers(struct signal_struct *sig)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
struct thread_group_cputimer *cputimer = &sig->cputimer;
unsigned long flags;
if (!cputimer->running)
@ -1072,6 +1072,10 @@ static void stop_process_timers(struct task_struct *tsk)
spin_lock_irqsave(&cputimer->lock, flags);
cputimer->running = 0;
spin_unlock_irqrestore(&cputimer->lock, flags);
sig->cputime_expires.prof_exp = cputime_zero;
sig->cputime_expires.virt_exp = cputime_zero;
sig->cputime_expires.sched_exp = 0;
}
static u32 onecputick;
@ -1133,7 +1137,7 @@ static void check_process_timers(struct task_struct *tsk,
list_empty(&timers[CPUCLOCK_VIRT]) &&
cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
list_empty(&timers[CPUCLOCK_SCHED])) {
stop_process_timers(tsk);
stop_process_timers(sig);
return;
}

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@ -22,6 +22,29 @@
#include "tick-internal.h"
/* Limit min_delta to a jiffie */
#define MIN_DELTA_LIMIT (NSEC_PER_SEC / HZ)
static int tick_increase_min_delta(struct clock_event_device *dev)
{
/* Nothing to do if we already reached the limit */
if (dev->min_delta_ns >= MIN_DELTA_LIMIT)
return -ETIME;
if (dev->min_delta_ns < 5000)
dev->min_delta_ns = 5000;
else
dev->min_delta_ns += dev->min_delta_ns >> 1;
if (dev->min_delta_ns > MIN_DELTA_LIMIT)
dev->min_delta_ns = MIN_DELTA_LIMIT;
printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n",
dev->name ? dev->name : "?",
(unsigned long long) dev->min_delta_ns);
return 0;
}
/**
* tick_program_event internal worker function
*/
@ -37,23 +60,28 @@ int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires,
if (!ret || !force)
return ret;
dev->retries++;
/*
* We tried 2 times to program the device with the given
* min_delta_ns. If that's not working then we double it
* We tried 3 times to program the device with the given
* min_delta_ns. If that's not working then we increase it
* and emit a warning.
*/
if (++i > 2) {
/* Increase the min. delta and try again */
if (!dev->min_delta_ns)
dev->min_delta_ns = 5000;
else
dev->min_delta_ns += dev->min_delta_ns >> 1;
printk(KERN_WARNING
"CE: %s increasing min_delta_ns to %llu nsec\n",
dev->name ? dev->name : "?",
(unsigned long long) dev->min_delta_ns << 1);
if (tick_increase_min_delta(dev)) {
/*
* Get out of the loop if min_delta_ns
* hit the limit already. That's
* better than staying here forever.
*
* We clear next_event so we have a
* chance that the box survives.
*/
printk(KERN_WARNING
"CE: Reprogramming failure. Giving up\n");
dev->next_event.tv64 = KTIME_MAX;
return -ETIME;
}
i = 0;
}

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@ -818,7 +818,8 @@ void update_wall_time(void)
shift = min(shift, maxshift);
while (offset >= timekeeper.cycle_interval) {
offset = logarithmic_accumulation(offset, shift);
shift--;
if(offset < timekeeper.cycle_interval<<shift)
shift--;
}
/* correct the clock when NTP error is too big */

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@ -228,6 +228,7 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
SEQ_printf(m, " event_handler: ");
print_name_offset(m, dev->event_handler);
SEQ_printf(m, "\n");
SEQ_printf(m, " retries: %lu\n", dev->retries);
}
static void timer_list_show_tickdevices(struct seq_file *m)
@ -257,7 +258,7 @@ static int timer_list_show(struct seq_file *m, void *v)
u64 now = ktime_to_ns(ktime_get());
int cpu;
SEQ_printf(m, "Timer List Version: v0.5\n");
SEQ_printf(m, "Timer List Version: v0.6\n");
SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);

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@ -880,6 +880,7 @@ int try_to_del_timer_sync(struct timer_list *timer)
if (base->running_timer == timer)
goto out;
timer_stats_timer_clear_start_info(timer);
ret = 0;
if (timer_pending(timer)) {
detach_timer(timer, 1);