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authorThomas Gleixner <tglx@linutronix.de>2008-12-22 23:05:28 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2009-01-18 10:35:28 -0800
commit7d75e838bb5a3b2ec427b4121d4404f6b5689aae (patch)
treedd214a68520cbc4f64b465bac67b75e8c684c6d8
parenta79fdfe90a3795eabf04430400ecb4711d939c5f (diff)
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sched_clock: prevent scd->clock from moving backwards, take #2
commit 1c5745aa380efb6417b5681104b007c8612fb496 upstream. Redo: 5b7dba4: sched_clock: prevent scd->clock from moving backwards which had to be reverted due to s2ram hangs: ca7e716: Revert "sched_clock: prevent scd->clock from moving backwards" ... this time with resume restoring GTOD later in the sequence taken into account as well. The "timekeeping_suspended" flag is not very nice but we cannot call into GTOD before it has been properly resumed and the scheduler will run very early in the resume sequence. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--include/linux/time.h1
-rw-r--r--kernel/sched_clock.c5
-rw-r--r--kernel/time/timekeeping.c7
3 files changed, 10 insertions, 3 deletions
diff --git a/include/linux/time.h b/include/linux/time.h
index e15206a7e82e..0095ad11d7e2 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -99,6 +99,7 @@ extern unsigned long read_persistent_clock(void);
extern int update_persistent_clock(struct timespec now);
extern int no_sync_cmos_clock __read_mostly;
void timekeeping_init(void);
+extern int timekeeping_suspended;
unsigned long get_seconds(void);
struct timespec current_kernel_time(void);
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index e8ab096ddfe3..a0b0852414cc 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -124,7 +124,7 @@ static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
clock = scd->tick_gtod + delta;
min_clock = wrap_max(scd->tick_gtod, scd->clock);
- max_clock = scd->tick_gtod + TICK_NSEC;
+ max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
clock = wrap_max(clock, min_clock);
clock = wrap_min(clock, max_clock);
@@ -227,6 +227,9 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
*/
void sched_clock_idle_wakeup_event(u64 delta_ns)
{
+ if (timekeeping_suspended)
+ return;
+
sched_clock_tick();
touch_softlockup_watchdog();
}
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e91c29f961c9..4220a2e1faab 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -46,6 +46,9 @@ struct timespec xtime __attribute__ ((aligned (16)));
struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
static unsigned long total_sleep_time; /* seconds */
+/* flag for if timekeeping is suspended */
+int __read_mostly timekeeping_suspended;
+
static struct timespec xtime_cache __attribute__ ((aligned (16)));
void update_xtime_cache(u64 nsec)
{
@@ -92,6 +95,8 @@ void getnstimeofday(struct timespec *ts)
unsigned long seq;
s64 nsecs;
+ WARN_ON(timekeeping_suspended);
+
do {
seq = read_seqbegin(&xtime_lock);
@@ -261,8 +266,6 @@ void __init timekeeping_init(void)
write_sequnlock_irqrestore(&xtime_lock, flags);
}
-/* flag for if timekeeping is suspended */
-static int timekeeping_suspended;
/* time in seconds when suspend began */
static unsigned long timekeeping_suspend_time;
/* xtime offset when we went into suspend */