From 8357929e6ae3661d5a3a7378a717f29873ea18c6 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 14 Nov 2011 13:06:21 -0800 Subject: ntp: Cleanup timex.h Move ntp_sycned to ntp.c and mark time_status as static. Also yank function declaration for non-existant function. CC: Thomas Gleixner CC: Eric Dumazet CC: Richard Cochran Signed-off-by: John Stultz --- kernel/time/ntp.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'kernel/time/ntp.c') diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index f6117a4c7cb8..ae7e13607d91 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -49,7 +49,7 @@ static struct hrtimer leap_timer; static int time_state = TIME_OK; /* clock status bits: */ -int time_status = STA_UNSYNC; +static int time_status = STA_UNSYNC; /* TAI offset (secs): */ static long time_tai; @@ -233,6 +233,17 @@ static inline void pps_fill_timex(struct timex *txc) #endif /* CONFIG_NTP_PPS */ + +/** + * ntp_synced - Returns 1 if the NTP status is not UNSYNC + * + */ +static inline int ntp_synced(void) +{ + return !(time_status & STA_UNSYNC); +} + + /* * NTP methods: */ -- cgit v1.2.3-59-g8ed1b From ea7cf49a7633c2b70125f59b4e3553d9181cb15d Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 14 Nov 2011 13:18:07 -0800 Subject: ntp: Access tick_length variable via ntp_tick_length() Currently the NTP managed tick_length value is accessed globally, in preparations for locking cleanups, make sure it is accessed via a function and mark it as static. CC: Thomas Gleixner CC: Eric Dumazet CC: Richard Cochran Signed-off-by: John Stultz --- include/linux/timex.h | 2 +- kernel/time/ntp.c | 9 ++++++++- kernel/time/timekeeping.c | 6 +++--- 3 files changed, 12 insertions(+), 5 deletions(-) (limited to 'kernel/time/ntp.c') diff --git a/include/linux/timex.h b/include/linux/timex.h index 92e01fc31ca6..b75e1864ed19 100644 --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -250,7 +250,7 @@ extern void ntp_clear(void); #define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ) /* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */ -extern u64 tick_length; +extern u64 ntp_tick_length(void); extern void second_overflow(void); extern int do_adjtimex(struct timex *); diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index ae7e13607d91..f131ba62da62 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -28,7 +28,7 @@ unsigned long tick_usec = TICK_USEC; /* ACTHZ period (nsecs): */ unsigned long tick_nsec; -u64 tick_length; +static u64 tick_length; static u64 tick_length_base; static struct hrtimer leap_timer; @@ -360,6 +360,13 @@ void ntp_clear(void) pps_clear(); } + +u64 ntp_tick_length(void) +{ + return tick_length; +} + + /* * Leap second processing. If in leap-insert state at the end of the * day, the system clock is set back one second; if in leap-delete diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index f5d4d226defb..cdae24655c8d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -811,7 +811,7 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, * Now calculate the error in (1 << look_ahead) ticks, but first * remove the single look ahead already included in the error. */ - tick_error = tick_length >> (timekeeper.ntp_error_shift + 1); + tick_error = ntp_tick_length() >> (timekeeper.ntp_error_shift + 1); tick_error -= timekeeper.xtime_interval >> 1; error = ((error - tick_error) >> look_ahead) + tick_error; @@ -994,7 +994,7 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) timekeeper.raw_time.tv_nsec = raw_nsecs; /* Accumulate error between NTP and clock interval */ - timekeeper.ntp_error += tick_length << shift; + timekeeper.ntp_error += ntp_tick_length() << shift; timekeeper.ntp_error -= (timekeeper.xtime_interval + timekeeper.xtime_remainder) << (timekeeper.ntp_error_shift + shift); @@ -1042,7 +1042,7 @@ static void update_wall_time(void) shift = ilog2(offset) - ilog2(timekeeper.cycle_interval); shift = max(0, shift); /* Bound shift to one less then what overflows tick_length */ - maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1; + maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; shift = min(shift, maxshift); while (offset >= timekeeper.cycle_interval) { offset = logarithmic_accumulation(offset, shift); -- cgit v1.2.3-59-g8ed1b From bd3312681f69207a40431981c1bce1afdc9b7975 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 14 Nov 2011 13:48:36 -0800 Subject: ntp: Add ntp_lock to replace xtime_locking Use a ntp_lock spin lock to replace xtime_lock locking in ntp.c CC: Thomas Gleixner CC: Eric Dumazet CC: Richard Cochran Signed-off-by: John Stultz --- kernel/time/ntp.c | 63 ++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 44 insertions(+), 19 deletions(-) (limited to 'kernel/time/ntp.c') diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index f131ba62da62..17fb1b9807d0 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -22,6 +22,9 @@ * NTP timekeeping variables: */ +DEFINE_SPINLOCK(ntp_lock); + + /* USER_HZ period (usecs): */ unsigned long tick_usec = TICK_USEC; @@ -133,7 +136,7 @@ static inline void pps_reset_freq_interval(void) /** * pps_clear - Clears the PPS state variables * - * Must be called while holding a write on the xtime_lock + * Must be called while holding a write on the ntp_lock */ static inline void pps_clear(void) { @@ -149,7 +152,7 @@ static inline void pps_clear(void) * the last PPS signal. When it reaches 0, indicate that PPS signal is * missing. * - * Must be called while holding a write on the xtime_lock + * Must be called while holding a write on the ntp_lock */ static inline void pps_dec_valid(void) { @@ -341,11 +344,13 @@ static void ntp_update_offset(long offset) /** * ntp_clear - Clears the NTP state variables - * - * Must be called while holding a write on the xtime_lock */ void ntp_clear(void) { + unsigned long flags; + + spin_lock_irqsave(&ntp_lock, flags); + time_adjust = 0; /* stop active adjtime() */ time_status |= STA_UNSYNC; time_maxerror = NTP_PHASE_LIMIT; @@ -358,12 +363,20 @@ void ntp_clear(void) /* Clear PPS state variables */ pps_clear(); + spin_unlock_irqrestore(&ntp_lock, flags); + } u64 ntp_tick_length(void) { - return tick_length; + unsigned long flags; + s64 ret; + + spin_lock_irqsave(&ntp_lock, flags); + ret = tick_length; + spin_unlock_irqrestore(&ntp_lock, flags); + return ret; } @@ -375,14 +388,15 @@ u64 ntp_tick_length(void) static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) { enum hrtimer_restart res = HRTIMER_NORESTART; + unsigned long flags; + int leap = 0; - write_seqlock(&xtime_lock); - + spin_lock_irqsave(&ntp_lock, flags); switch (time_state) { case TIME_OK: break; case TIME_INS: - timekeeping_leap_insert(-1); + leap = -1; time_state = TIME_OOP; printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n"); @@ -390,7 +404,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) res = HRTIMER_RESTART; break; case TIME_DEL: - timekeeping_leap_insert(1); + leap = 1; time_tai--; time_state = TIME_WAIT; printk(KERN_NOTICE @@ -405,8 +419,14 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) time_state = TIME_OK; break; } + spin_unlock_irqrestore(&ntp_lock, flags); - write_sequnlock(&xtime_lock); + /* + * We have to call this outside of the ntp_lock to keep + * the proper locking hierarchy + */ + if (leap) + timekeeping_leap_insert(leap); return res; } @@ -422,6 +442,9 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) void second_overflow(void) { s64 delta; + unsigned long flags; + + spin_lock_irqsave(&ntp_lock, flags); /* Bump the maxerror field */ time_maxerror += MAXFREQ / NSEC_PER_USEC; @@ -441,23 +464,25 @@ void second_overflow(void) pps_dec_valid(); if (!time_adjust) - return; + goto out; if (time_adjust > MAX_TICKADJ) { time_adjust -= MAX_TICKADJ; tick_length += MAX_TICKADJ_SCALED; - return; + goto out; } if (time_adjust < -MAX_TICKADJ) { time_adjust += MAX_TICKADJ; tick_length -= MAX_TICKADJ_SCALED; - return; + goto out; } tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ) << NTP_SCALE_SHIFT; time_adjust = 0; +out: + spin_unlock_irqrestore(&ntp_lock, flags); } #ifdef CONFIG_GENERIC_CMOS_UPDATE @@ -681,7 +706,7 @@ int do_adjtimex(struct timex *txc) getnstimeofday(&ts); - write_seqlock_irq(&xtime_lock); + spin_lock_irq(&ntp_lock); if (txc->modes & ADJ_ADJTIME) { long save_adjust = time_adjust; @@ -723,7 +748,7 @@ int do_adjtimex(struct timex *txc) /* fill PPS status fields */ pps_fill_timex(txc); - write_sequnlock_irq(&xtime_lock); + spin_unlock_irq(&ntp_lock); txc->time.tv_sec = ts.tv_sec; txc->time.tv_usec = ts.tv_nsec; @@ -921,7 +946,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) pts_norm = pps_normalize_ts(*phase_ts); - write_seqlock_irqsave(&xtime_lock, flags); + spin_lock_irqsave(&ntp_lock, flags); /* clear the error bits, they will be set again if needed */ time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR); @@ -934,7 +959,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) * just start the frequency interval */ if (unlikely(pps_fbase.tv_sec == 0)) { pps_fbase = *raw_ts; - write_sequnlock_irqrestore(&xtime_lock, flags); + spin_unlock_irqrestore(&ntp_lock, flags); return; } @@ -949,7 +974,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) time_status |= STA_PPSJITTER; /* restart the frequency calibration interval */ pps_fbase = *raw_ts; - write_sequnlock_irqrestore(&xtime_lock, flags); + spin_unlock_irqrestore(&ntp_lock, flags); pr_err("hardpps: PPSJITTER: bad pulse\n"); return; } @@ -966,7 +991,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) hardpps_update_phase(pts_norm.nsec); - write_sequnlock_irqrestore(&xtime_lock, flags); + spin_unlock_irqrestore(&ntp_lock, flags); } EXPORT_SYMBOL(hardpps); -- cgit v1.2.3-59-g8ed1b From a078c6d0e6288fad6d83fb6d5edd91ddb7b6ab33 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Thu, 15 Mar 2012 12:36:14 -0400 Subject: ntp: Fix integer overflow when setting time 'long secs' is passed as divisor to div_s64, which accepts a 32bit divisor. On 64bit machines that value is trimmed back from 8 bytes back to 4, causing a divide by zero when the number is bigger than (1 << 32) - 1 and all 32 lower bits are 0. Use div64_long() instead. Signed-off-by: Sasha Levin Cc: johnstul@us.ibm.com Link: http://lkml.kernel.org/r/1331829374-31543-2-git-send-email-levinsasha928@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner --- kernel/time/ntp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/time/ntp.c') diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 17fb1b9807d0..6e039b144daf 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -289,7 +289,7 @@ static inline s64 ntp_update_offset_fll(s64 offset64, long secs) time_status |= STA_MODE; - return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs); + return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs); } static void ntp_update_offset(long offset) -- cgit v1.2.3-59-g8ed1b From 6b43ae8a619d17c4935c3320d2ef9e92bdeed05d Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 15 Mar 2012 13:04:03 -0700 Subject: ntp: Fix leap-second hrtimer livelock Since commit 7dffa3c673fbcf835cd7be80bb4aec8ad3f51168 the ntp subsystem has used an hrtimer for triggering the leapsecond adjustment. However, this can cause a potential livelock. Thomas diagnosed this as the following pattern: CPU 0 CPU 1 do_adjtimex() spin_lock_irq(&ntp_lock); process_adjtimex_modes(); timer_interrupt() process_adj_status(); do_timer() ntp_start_leap_timer(); write_lock(&xtime_lock); hrtimer_start(); update_wall_time(); hrtimer_reprogram(); ntp_tick_length() tick_program_event() spin_lock(&ntp_lock); clockevents_program_event() ktime_get() seq = req_seqbegin(xtime_lock); This patch tries to avoid the problem by reverting back to not using an hrtimer to inject leapseconds, and instead we handle the leapsecond processing in the second_overflow() function. The downside to this change is that on systems that support highres timers, the leap second processing will occur on a HZ tick boundary, (ie: ~1-10ms, depending on HZ) after the leap second instead of possibly sooner (~34us in my tests w/ x86_64 lapic). This patch applies on top of tip/timers/core. CC: Sasha Levin CC: Thomas Gleixner Reported-by: Sasha Levin Diagnoised-by: Thomas Gleixner Tested-by: Sasha Levin Signed-off-by: John Stultz --- include/linux/timex.h | 2 +- kernel/time/ntp.c | 128 +++++++++++++++------------------------------- kernel/time/timekeeping.c | 20 +++----- 3 files changed, 48 insertions(+), 102 deletions(-) (limited to 'kernel/time/ntp.c') diff --git a/include/linux/timex.h b/include/linux/timex.h index b75e1864ed19..99bc88b1fc02 100644 --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -252,7 +252,7 @@ extern void ntp_clear(void); /* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */ extern u64 ntp_tick_length(void); -extern void second_overflow(void); +extern int second_overflow(unsigned long secs); extern int do_adjtimex(struct timex *); extern void hardpps(const struct timespec *, const struct timespec *); diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 6e039b144daf..3d17ebd47fa2 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -34,8 +34,6 @@ unsigned long tick_nsec; static u64 tick_length; static u64 tick_length_base; -static struct hrtimer leap_timer; - #define MAX_TICKADJ 500LL /* usecs */ #define MAX_TICKADJ_SCALED \ (((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ) @@ -381,70 +379,63 @@ u64 ntp_tick_length(void) /* - * Leap second processing. If in leap-insert state at the end of the - * day, the system clock is set back one second; if in leap-delete - * state, the system clock is set ahead one second. + * this routine handles the overflow of the microsecond field + * + * The tricky bits of code to handle the accurate clock support + * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame. + * They were originally developed for SUN and DEC kernels. + * All the kudos should go to Dave for this stuff. + * + * Also handles leap second processing, and returns leap offset */ -static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) +int second_overflow(unsigned long secs) { - enum hrtimer_restart res = HRTIMER_NORESTART; - unsigned long flags; + s64 delta; int leap = 0; + unsigned long flags; spin_lock_irqsave(&ntp_lock, flags); + + /* + * Leap second processing. If in leap-insert state at the end of the + * day, the system clock is set back one second; if in leap-delete + * state, the system clock is set ahead one second. + */ switch (time_state) { case TIME_OK: + if (time_status & STA_INS) + time_state = TIME_INS; + else if (time_status & STA_DEL) + time_state = TIME_DEL; break; case TIME_INS: - leap = -1; - time_state = TIME_OOP; - printk(KERN_NOTICE - "Clock: inserting leap second 23:59:60 UTC\n"); - hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC); - res = HRTIMER_RESTART; + if (secs % 86400 == 0) { + leap = -1; + time_state = TIME_OOP; + printk(KERN_NOTICE + "Clock: inserting leap second 23:59:60 UTC\n"); + } break; case TIME_DEL: - leap = 1; - time_tai--; - time_state = TIME_WAIT; - printk(KERN_NOTICE - "Clock: deleting leap second 23:59:59 UTC\n"); + if ((secs + 1) % 86400 == 0) { + leap = 1; + time_tai--; + time_state = TIME_WAIT; + printk(KERN_NOTICE + "Clock: deleting leap second 23:59:59 UTC\n"); + } break; case TIME_OOP: time_tai++; time_state = TIME_WAIT; - /* fall through */ + break; + case TIME_WAIT: if (!(time_status & (STA_INS | STA_DEL))) time_state = TIME_OK; break; } - spin_unlock_irqrestore(&ntp_lock, flags); - - /* - * We have to call this outside of the ntp_lock to keep - * the proper locking hierarchy - */ - if (leap) - timekeeping_leap_insert(leap); - - return res; -} - -/* - * this routine handles the overflow of the microsecond field - * - * The tricky bits of code to handle the accurate clock support - * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame. - * They were originally developed for SUN and DEC kernels. - * All the kudos should go to Dave for this stuff. - */ -void second_overflow(void) -{ - s64 delta; - unsigned long flags; - spin_lock_irqsave(&ntp_lock, flags); /* Bump the maxerror field */ time_maxerror += MAXFREQ / NSEC_PER_USEC; @@ -481,8 +472,13 @@ void second_overflow(void) tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ) << NTP_SCALE_SHIFT; time_adjust = 0; + + + out: spin_unlock_irqrestore(&ntp_lock, flags); + + return leap; } #ifdef CONFIG_GENERIC_CMOS_UPDATE @@ -544,27 +540,6 @@ static void notify_cmos_timer(void) static inline void notify_cmos_timer(void) { } #endif -/* - * Start the leap seconds timer: - */ -static inline void ntp_start_leap_timer(struct timespec *ts) -{ - long now = ts->tv_sec; - - if (time_status & STA_INS) { - time_state = TIME_INS; - now += 86400 - now % 86400; - hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS); - - return; - } - - if (time_status & STA_DEL) { - time_state = TIME_DEL; - now += 86400 - (now + 1) % 86400; - hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS); - } -} /* * Propagate a new txc->status value into the NTP state: @@ -589,22 +564,6 @@ static inline void process_adj_status(struct timex *txc, struct timespec *ts) time_status &= STA_RONLY; time_status |= txc->status & ~STA_RONLY; - switch (time_state) { - case TIME_OK: - ntp_start_leap_timer(ts); - break; - case TIME_INS: - case TIME_DEL: - time_state = TIME_OK; - ntp_start_leap_timer(ts); - case TIME_WAIT: - if (!(time_status & (STA_INS | STA_DEL))) - time_state = TIME_OK; - break; - case TIME_OOP: - hrtimer_restart(&leap_timer); - break; - } } /* * Called with the xtime lock held, so we can access and modify @@ -686,9 +645,6 @@ int do_adjtimex(struct timex *txc) (txc->tick < 900000/USER_HZ || txc->tick > 1100000/USER_HZ)) return -EINVAL; - - if (txc->modes & ADJ_STATUS && time_state != TIME_OK) - hrtimer_cancel(&leap_timer); } if (txc->modes & ADJ_SETOFFSET) { @@ -1010,6 +966,4 @@ __setup("ntp_tick_adj=", ntp_tick_adj_setup); void __init ntp_init(void) { ntp_clear(); - hrtimer_init(&leap_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS); - leap_timer.function = ntp_leap_second; } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index b53da5ecbea2..5d76e09ddd3d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -184,18 +184,6 @@ static void timekeeping_update(bool clearntp) } -void timekeeping_leap_insert(int leapsecond) -{ - unsigned long flags; - - write_seqlock_irqsave(&timekeeper.lock, flags); - timekeeper.xtime.tv_sec += leapsecond; - timekeeper.wall_to_monotonic.tv_sec -= leapsecond; - timekeeping_update(false); - write_sequnlock_irqrestore(&timekeeper.lock, flags); - -} - /** * timekeeping_forward_now - update clock to the current time * @@ -969,9 +957,11 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) timekeeper.xtime_nsec += timekeeper.xtime_interval << shift; while (timekeeper.xtime_nsec >= nsecps) { + int leap; timekeeper.xtime_nsec -= nsecps; timekeeper.xtime.tv_sec++; - second_overflow(); + leap = second_overflow(timekeeper.xtime.tv_sec); + timekeeper.xtime.tv_sec += leap; } /* Accumulate raw time */ @@ -1082,9 +1072,11 @@ static void update_wall_time(void) * xtime.tv_nsec isn't larger then NSEC_PER_SEC */ if (unlikely(timekeeper.xtime.tv_nsec >= NSEC_PER_SEC)) { + int leap; timekeeper.xtime.tv_nsec -= NSEC_PER_SEC; timekeeper.xtime.tv_sec++; - second_overflow(); + leap = second_overflow(timekeeper.xtime.tv_sec); + timekeeper.xtime.tv_sec += leap; } timekeeping_update(false); -- cgit v1.2.3-59-g8ed1b From 335dd85895abeca1957d5eaa3013dfe8dc60c7d7 Mon Sep 17 00:00:00 2001 From: Cesar Eduardo Barros Date: Sat, 11 Feb 2012 17:54:59 -0200 Subject: time: remove no_sync_cmos_clock Commit 9863c90f682fba34cdc26c3437e8c00da6c83fa4 (x86, vmware: Remove deprecated VMI kernel support) removed the only place which set no_sync_cmos_clock. Since that commit, this variable is never set. Signed-off-by: Cesar Eduardo Barros Signed-off-by: John Stultz --- include/linux/time.h | 1 - kernel/time/ntp.c | 6 +----- 2 files changed, 1 insertion(+), 6 deletions(-) (limited to 'kernel/time/ntp.c') diff --git a/include/linux/time.h b/include/linux/time.h index b3061782dec3..97734e9409c6 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -116,7 +116,6 @@ static inline struct timespec timespec_sub(struct timespec lhs, extern void read_persistent_clock(struct timespec *ts); extern void read_boot_clock(struct timespec *ts); extern int update_persistent_clock(struct timespec now); -extern int no_sync_cmos_clock __read_mostly; void timekeeping_init(void); extern int timekeeping_suspended; diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 3d17ebd47fa2..f03fd83b170b 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -483,9 +483,6 @@ out: #ifdef CONFIG_GENERIC_CMOS_UPDATE -/* Disable the cmos update - used by virtualization and embedded */ -int no_sync_cmos_clock __read_mostly; - static void sync_cmos_clock(struct work_struct *work); static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock); @@ -532,8 +529,7 @@ static void sync_cmos_clock(struct work_struct *work) static void notify_cmos_timer(void) { - if (!no_sync_cmos_clock) - schedule_delayed_work(&sync_cmos_work, 0); + schedule_delayed_work(&sync_cmos_work, 0); } #else -- cgit v1.2.3-59-g8ed1b