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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2008-03-09 10:06:49 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-03-09 10:06:49 -0700
commitbf5a25e1fff88a1066e20cc7263329405e4939f6 (patch)
tree95822dc50801e21cf1ad1e6aa7b58af898156517
parent83f7a2c118833d3738b4d162ea3c17d0bd8ffa94 (diff)
parent10a398d04c4a1fc395840f4d040493375f562302 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt
* git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt: time: remove obsolete CLOCK_TICK_ADJUST time: don't touch an offlined CPU's ts->tick_stopped in tick_cancel_sched_timer() time: prevent the loop in timespec_add_ns() from being optimised away ntp: use unsigned input for do_div()
-rw-r--r--include/linux/time.h4
-rw-r--r--include/linux/timex.h9
-rw-r--r--kernel/time/ntp.c23
-rw-r--r--kernel/time/tick-sched.c2
-rw-r--r--kernel/time/timekeeping.c6
5 files changed, 25 insertions, 19 deletions
diff --git a/include/linux/time.h b/include/linux/time.h
index 2091a19f165..d32ef0ad4c0 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -174,6 +174,10 @@ static inline void timespec_add_ns(struct timespec *a, u64 ns)
{
ns += a->tv_nsec;
while(unlikely(ns >= NSEC_PER_SEC)) {
+ /* The following asm() prevents the compiler from
+ * optimising this loop into a modulo operation. */
+ asm("" : "+r"(ns));
+
ns -= NSEC_PER_SEC;
a->tv_sec++;
}
diff --git a/include/linux/timex.h b/include/linux/timex.h
index c3f374786a4..8ea3e71ba7f 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -232,14 +232,7 @@ static inline int ntp_synced(void)
#else
#define NTP_INTERVAL_FREQ (HZ)
#endif
-
-#define CLOCK_TICK_OVERFLOW (LATCH * HZ - CLOCK_TICK_RATE)
-#define CLOCK_TICK_ADJUST (((s64)CLOCK_TICK_OVERFLOW * NSEC_PER_SEC) / \
- (s64)CLOCK_TICK_RATE)
-
-/* Because using NSEC_PER_SEC would be too easy */
-#define NTP_INTERVAL_LENGTH ((((s64)TICK_USEC * NSEC_PER_USEC * USER_HZ) + \
- CLOCK_TICK_ADJUST) / NTP_INTERVAL_FREQ)
+#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
/* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */
extern u64 current_tick_length(void);
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index c88b5910e7a..5fd9b946977 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -42,12 +42,13 @@ long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
long time_freq; /* frequency offset (scaled ppm)*/
static long time_reftime; /* time at last adjustment (s) */
long time_adjust;
+static long ntp_tick_adj;
static void ntp_update_frequency(void)
{
u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
<< TICK_LENGTH_SHIFT;
- second_length += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
+ second_length += (s64)ntp_tick_adj << TICK_LENGTH_SHIFT;
second_length += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC);
tick_length_base = second_length;
@@ -342,14 +343,16 @@ int do_adjtimex(struct timex *txc)
freq_adj = shift_right(freq_adj, time_constant * 2 +
(SHIFT_PLL + 2) * 2 - SHIFT_NSEC);
if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
+ u64 utemp64;
temp64 = time_offset << (SHIFT_NSEC - SHIFT_FLL);
if (time_offset < 0) {
- temp64 = -temp64;
- do_div(temp64, mtemp);
- freq_adj -= temp64;
+ utemp64 = -temp64;
+ do_div(utemp64, mtemp);
+ freq_adj -= utemp64;
} else {
- do_div(temp64, mtemp);
- freq_adj += temp64;
+ utemp64 = temp64;
+ do_div(utemp64, mtemp);
+ freq_adj += utemp64;
}
}
freq_adj += time_freq;
@@ -400,3 +403,11 @@ leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
notify_cmos_timer();
return(result);
}
+
+static int __init ntp_tick_adj_setup(char *str)
+{
+ ntp_tick_adj = simple_strtol(str, NULL, 0);
+ return 1;
+}
+
+__setup("ntp_tick_adj=", ntp_tick_adj_setup);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 2968298f8f3..686da821d37 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -640,7 +640,7 @@ void tick_cancel_sched_timer(int cpu)
if (ts->sched_timer.base)
hrtimer_cancel(&ts->sched_timer);
- ts->tick_stopped = 0;
+
ts->nohz_mode = NOHZ_MODE_INACTIVE;
}
#endif /* HIGH_RES_TIMERS */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 1af9fb050fe..671af612b76 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -187,8 +187,7 @@ static void change_clocksource(void)
clock->error = 0;
clock->xtime_nsec = 0;
- clocksource_calculate_interval(clock,
- (unsigned long)(current_tick_length()>>TICK_LENGTH_SHIFT));
+ clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
tick_clock_notify();
@@ -245,8 +244,7 @@ void __init timekeeping_init(void)
ntp_clear();
clock = clocksource_get_next();
- clocksource_calculate_interval(clock,
- (unsigned long)(current_tick_length()>>TICK_LENGTH_SHIFT));
+ clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
clock->cycle_last = clocksource_read(clock);
xtime.tv_sec = sec;