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-rw-r--r--kernel/time/clocksource.c36
-rw-r--r--kernel/time/ntp.c10
-rw-r--r--kernel/time/tick-oneshot.c52
-rw-r--r--kernel/time/timecompare.c1
-rw-r--r--kernel/time/timekeeping.c6
-rw-r--r--kernel/time/timer_list.c3
6 files changed, 85 insertions, 23 deletions
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index e85c234..1f5dde6 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -343,7 +343,19 @@ static void clocksource_resume_watchdog(void)
{
unsigned long flags;
- spin_lock_irqsave(&watchdog_lock, flags);
+ /*
+ * We use trylock here to avoid a potential dead lock when
+ * kgdb calls this code after the kernel has been stopped with
+ * watchdog_lock held. When watchdog_lock is held we just
+ * return and accept, that the watchdog might trigger and mark
+ * the monitored clock source (usually TSC) unstable.
+ *
+ * This does not affect the other caller clocksource_resume()
+ * because at this point the kernel is UP, interrupts are
+ * disabled and nothing can hold watchdog_lock.
+ */
+ if (!spin_trylock_irqsave(&watchdog_lock, flags))
+ return;
clocksource_reset_watchdog();
spin_unlock_irqrestore(&watchdog_lock, flags);
}
@@ -441,6 +453,18 @@ static inline int clocksource_watchdog_kthread(void *data) { return 0; }
#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */
/**
+ * clocksource_suspend - suspend the clocksource(s)
+ */
+void clocksource_suspend(void)
+{
+ struct clocksource *cs;
+
+ list_for_each_entry_reverse(cs, &clocksource_list, list)
+ if (cs->suspend)
+ cs->suspend(cs);
+}
+
+/**
* clocksource_resume - resume the clocksource(s)
*/
void clocksource_resume(void)
@@ -449,7 +473,7 @@ void clocksource_resume(void)
list_for_each_entry(cs, &clocksource_list, list)
if (cs->resume)
- cs->resume();
+ cs->resume(cs);
clocksource_resume_watchdog();
}
@@ -458,8 +482,8 @@ void clocksource_resume(void)
* clocksource_touch_watchdog - Update watchdog
*
* Update the watchdog after exception contexts such as kgdb so as not
- * to incorrectly trip the watchdog.
- *
+ * to incorrectly trip the watchdog. This might fail when the kernel
+ * was stopped in code which holds watchdog_lock.
*/
void clocksource_touch_watchdog(void)
{
@@ -568,6 +592,10 @@ static inline void clocksource_select(void) { }
*/
static int __init clocksource_done_booting(void)
{
+ mutex_lock(&clocksource_mutex);
+ curr_clocksource = clocksource_default_clock();
+ mutex_unlock(&clocksource_mutex);
+
finished_booting = 1;
/*
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 4800f93..7c0f180 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -58,10 +58,10 @@ static s64 time_offset;
static long time_constant = 2;
/* maximum error (usecs): */
-long time_maxerror = NTP_PHASE_LIMIT;
+static long time_maxerror = NTP_PHASE_LIMIT;
/* estimated error (usecs): */
-long time_esterror = NTP_PHASE_LIMIT;
+static long time_esterror = NTP_PHASE_LIMIT;
/* frequency offset (scaled nsecs/secs): */
static s64 time_freq;
@@ -142,11 +142,11 @@ static void ntp_update_offset(long offset)
* Select how the frequency is to be controlled
* and in which mode (PLL or FLL).
*/
- secs = xtime.tv_sec - time_reftime;
+ secs = get_seconds() - time_reftime;
if (unlikely(time_status & STA_FREQHOLD))
secs = 0;
- time_reftime = xtime.tv_sec;
+ time_reftime = get_seconds();
offset64 = offset;
freq_adj = (offset64 * secs) <<
@@ -368,7 +368,7 @@ static inline void process_adj_status(struct timex *txc, struct timespec *ts)
* reference time to current time.
*/
if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
- time_reftime = xtime.tv_sec;
+ time_reftime = get_seconds();
/* only set allowed bits */
time_status &= STA_RONLY;
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index 0a8a213..aada0e5 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;
}
diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c
index 12f5c55..ac38fbb 100644
--- a/kernel/time/timecompare.c
+++ b/kernel/time/timecompare.c
@@ -19,6 +19,7 @@
#include <linux/timecompare.h>
#include <linux/module.h>
+#include <linux/slab.h>
#include <linux/math64.h>
/*
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 7faaa32..39f6177 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -622,6 +622,7 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
write_sequnlock_irqrestore(&xtime_lock, flags);
clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
+ clocksource_suspend();
return 0;
}
@@ -817,7 +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 */
@@ -880,6 +882,7 @@ void getboottime(struct timespec *ts)
set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
}
+EXPORT_SYMBOL_GPL(getboottime);
/**
* monotonic_to_bootbased - Convert the monotonic time to boot based.
@@ -889,6 +892,7 @@ void monotonic_to_bootbased(struct timespec *ts)
{
*ts = timespec_add_safe(*ts, total_sleep_time);
}
+EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
unsigned long get_seconds(void)
{
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index bdfb8dd..1a4a7dd 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -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);
generated by cgit v1.1 at 2025-08-17 01:35:03 +0000