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authorThomas Gleixner <tglx@linutronix.de>2008-12-22 17:05:28 -0500
committerIngo Molnar <mingo@elte.hu>2008-12-31 03:53:21 -0500
commit1c5745aa380efb6417b5681104b007c8612fb496 (patch)
tree263b81742f7973c0dd86efe414a79a324c0769e4
parent6a94cb73064c952255336cc57731904174b2c58f (diff)
sched_clock: prevent scd->clock from moving backwards, take #2
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. Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-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 ce321ac5c8f8..fbbd2a1c92ba 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -105,6 +105,7 @@ extern unsigned long read_persistent_clock(void);
105extern int update_persistent_clock(struct timespec now); 105extern int update_persistent_clock(struct timespec now);
106extern int no_sync_cmos_clock __read_mostly; 106extern int no_sync_cmos_clock __read_mostly;
107void timekeeping_init(void); 107void timekeeping_init(void);
108extern int timekeeping_suspended;
108 109
109unsigned long get_seconds(void); 110unsigned long get_seconds(void);
110struct timespec current_kernel_time(void); 111struct 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)
124 124
125 clock = scd->tick_gtod + delta; 125 clock = scd->tick_gtod + delta;
126 min_clock = wrap_max(scd->tick_gtod, scd->clock); 126 min_clock = wrap_max(scd->tick_gtod, scd->clock);
127 max_clock = scd->tick_gtod + TICK_NSEC; 127 max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
128 128
129 clock = wrap_max(clock, min_clock); 129 clock = wrap_max(clock, min_clock);
130 clock = wrap_min(clock, max_clock); 130 clock = wrap_min(clock, max_clock);
@@ -227,6 +227,9 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
227 */ 227 */
228void sched_clock_idle_wakeup_event(u64 delta_ns) 228void sched_clock_idle_wakeup_event(u64 delta_ns)
229{ 229{
230 if (timekeeping_suspended)
231 return;
232
230 sched_clock_tick(); 233 sched_clock_tick();
231 touch_softlockup_watchdog(); 234 touch_softlockup_watchdog();
232} 235}
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index fa05e88aa76f..900f1b6598d1 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -46,6 +46,9 @@ struct timespec xtime __attribute__ ((aligned (16)));
46struct timespec wall_to_monotonic __attribute__ ((aligned (16))); 46struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
47static unsigned long total_sleep_time; /* seconds */ 47static unsigned long total_sleep_time; /* seconds */
48 48
49/* flag for if timekeeping is suspended */
50int __read_mostly timekeeping_suspended;
51
49static struct timespec xtime_cache __attribute__ ((aligned (16))); 52static struct timespec xtime_cache __attribute__ ((aligned (16)));
50void update_xtime_cache(u64 nsec) 53void update_xtime_cache(u64 nsec)
51{ 54{
@@ -92,6 +95,8 @@ void getnstimeofday(struct timespec *ts)
92 unsigned long seq; 95 unsigned long seq;
93 s64 nsecs; 96 s64 nsecs;
94 97
98 WARN_ON(timekeeping_suspended);
99
95 do { 100 do {
96 seq = read_seqbegin(&xtime_lock); 101 seq = read_seqbegin(&xtime_lock);
97 102
@@ -299,8 +304,6 @@ void __init timekeeping_init(void)
299 write_sequnlock_irqrestore(&xtime_lock, flags); 304 write_sequnlock_irqrestore(&xtime_lock, flags);
300} 305}
301 306
302/* flag for if timekeeping is suspended */
303static int timekeeping_suspended;
304/* time in seconds when suspend began */ 307/* time in seconds when suspend began */
305static unsigned long timekeeping_suspend_time; 308static unsigned long timekeeping_suspend_time;
306 309