diff options
author | Frederic Weisbecker <fweisbec@gmail.com> | 2010-04-30 19:11:13 +0200 |
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committer | Frederic Weisbecker <fweisbec@gmail.com> | 2010-04-30 19:12:47 +0200 |
commit | 868c522b1b75fd3fd3e6a636b4c344ac08edf13a (patch) | |
tree | d85b984d9818abc3ccc0237eb53b710d9e96c39e /kernel/time/tick-oneshot.c | |
parent | bd6d29c25bb1a24a4c160ec5de43e0004e01f72b (diff) | |
parent | 66f41d4c5c8a5deed66fdcc84509376c9a0bf9d8 (diff) |
Merge commit 'v2.6.34-rc6' into core/locking
Merge reason: Further lockdep patches depend on per cpu updates
made in -rc1.
Diffstat (limited to 'kernel/time/tick-oneshot.c')
-rw-r--r-- | kernel/time/tick-oneshot.c | 52 |
1 files changed, 40 insertions, 12 deletions
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c index 0a8a213016f..aada0e52680 100644 --- a/kernel/time/tick-oneshot.c +++ b/kernel/time/tick-oneshot.c @@ -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; } |