Revert "time: Remove xtime_cache"

[sfrench/cifs-2.6.git] / kernel / time / timekeeping.c

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index af4135f058254b0607fc2594f2c52ae6355e76b1..7faaa32fbf4f37d1d2efdedf9a3087a98455f7b6 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -165,6 +165,13 @@ struct timespec raw_time;
 /* 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)
+{
+       xtime_cache = xtime;
+       timespec_add_ns(&xtime_cache, nsec);
+}
+
 /* must hold xtime_lock */
 void timekeeping_leap_insert(int leapsecond)
 {
@@ -325,6 +332,8 @@ int do_settimeofday(struct timespec *tv)
 
        xtime = *tv;
 
+       update_xtime_cache(0);
+
        timekeeper.ntp_error = 0;
        ntp_clear();
 
@@ -550,6 +559,7 @@ void __init timekeeping_init(void)
        }
        set_normalized_timespec(&wall_to_monotonic,
                                -boot.tv_sec, -boot.tv_nsec);
+       update_xtime_cache(0);
        total_sleep_time.tv_sec = 0;
        total_sleep_time.tv_nsec = 0;
        write_sequnlock_irqrestore(&xtime_lock, flags);
@@ -583,6 +593,7 @@ static int timekeeping_resume(struct sys_device *dev)
                wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
                total_sleep_time = timespec_add_safe(total_sleep_time, ts);
        }
+       update_xtime_cache(0);
        /* re-base the last cycle value */
        timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
        timekeeper.ntp_error = 0;
@@ -722,6 +733,7 @@ static void timekeeping_adjust(s64 offset)
                                timekeeper.ntp_error_shift;
 }
 
+
 /**
  * logarithmic_accumulation - shifted accumulation of cycles
  *
@@ -765,6 +777,7 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
        return offset;
 }
 
+
 /**
  * update_wall_time - Uses the current clocksource to increment the wall time
  *
@@ -774,6 +787,7 @@ void update_wall_time(void)
 {
        struct clocksource *clock;
        cycle_t offset;
+       u64 nsecs;
        int shift = 0, maxshift;
 
        /* Make sure we're fully resumed: */
@@ -839,6 +853,9 @@ void update_wall_time(void)
        timekeeper.ntp_error += timekeeper.xtime_nsec <<
                                timekeeper.ntp_error_shift;
 
+       nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift);
+       update_xtime_cache(nsecs);
+
        /* check to see if there is a new clocksource to use */
        update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
 }
@@ -875,13 +892,13 @@ void monotonic_to_bootbased(struct timespec *ts)
 
 unsigned long get_seconds(void)
 {
-       return xtime.tv_sec;
+       return xtime_cache.tv_sec;
 }
 EXPORT_SYMBOL(get_seconds);
 
 struct timespec __current_kernel_time(void)
 {
-       return xtime;
+       return xtime_cache;
 }
 
 struct timespec current_kernel_time(void)
@@ -891,7 +908,8 @@ struct timespec current_kernel_time(void)
 
        do {
                seq = read_seqbegin(&xtime_lock);
-               now = xtime;
+
+               now = xtime_cache;
        } while (read_seqretry(&xtime_lock, seq));
 
        return now;
@@ -905,7 +923,8 @@ struct timespec get_monotonic_coarse(void)
 
        do {
                seq = read_seqbegin(&xtime_lock);
-               now = xtime;
+
+               now = xtime_cache;
                mono = wall_to_monotonic;
        } while (read_seqretry(&xtime_lock, seq));