From 82644459c592a28a3eab682f9b88d81019ddfe8b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 21 Jul 2007 04:37:37 -0700 Subject: NTP: move the cmos update code into ntp.c i386 and sparc64 have the identical code to update the cmos clock. Move it into kernel/time/ntp.c as there are other architectures coming along with the same requirements. [akpm@linux-foundation.org: build fixes] Signed-off-by: Thomas Gleixner Cc: Chris Wright Cc: Ingo Molnar Cc: john stultz Cc: David Miller Cc: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/time.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/time.h') diff --git a/include/linux/time.h b/include/linux/time.h index ec3b0ced0afe..e6aea5146e5d 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -4,6 +4,7 @@ #include #ifdef __KERNEL__ +# include # include #endif @@ -94,6 +95,8 @@ extern struct timespec wall_to_monotonic; extern seqlock_t xtime_lock __attribute__((weak)); 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); static inline unsigned long get_seconds(void) -- cgit v1.3-14-g43fede From 2c6b47de17c75d553de3e2fb426d8298d2074585 Mon Sep 17 00:00:00 2001 From: john stultz Date: Tue, 24 Jul 2007 17:47:43 -0700 Subject: Cleanup non-arch xtime uses, use get_seconds() or current_kernel_time(). This avoids use of the kernel-internal "xtime" variable directly outside of the actual time-related functions. Instead, use the helper functions that we already have available to us. This doesn't actually change any behaviour, but this will allow us to fix the fact that "xtime" isn't updated very often with CONFIG_NO_HZ (because much of the realtime information is maintained as separate offsets to 'xtime'), which has caused interfaces that use xtime directly to get a time that is out of sync with the real-time clock by up to a third of a second or so. Signed-off-by: John Stultz Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Linus Torvalds --- drivers/rtc/class.c | 5 +++-- drivers/s390/net/ctcmain.c | 6 +++--- drivers/s390/net/netiucv.c | 4 ++-- include/linux/time.h | 2 +- kernel/acct.c | 2 +- kernel/hrtimer.c | 2 +- kernel/time.c | 16 ---------------- kernel/time/timekeeping.c | 16 ++++++++++++++++ kernel/tsacct.c | 2 +- net/rxrpc/af_rxrpc.c | 2 +- net/rxrpc/ar-connection.c | 4 ++-- net/rxrpc/ar-transport.c | 4 ++-- net/rxrpc/rxkad.c | 2 +- 13 files changed, 34 insertions(+), 33 deletions(-) (limited to 'include/linux/time.h') diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 8b3cd31d6a61..10ab3b71ffc6 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -46,6 +46,7 @@ static int rtc_suspend(struct device *dev, pm_message_t mesg) { struct rtc_device *rtc = to_rtc_device(dev); struct rtc_time tm; + struct timespec ts = current_kernel_time(); if (strncmp(rtc->dev.bus_id, CONFIG_RTC_HCTOSYS_DEVICE, @@ -57,8 +58,8 @@ static int rtc_suspend(struct device *dev, pm_message_t mesg) /* RTC precision is 1 second; adjust delta for avg 1/2 sec err */ set_normalized_timespec(&delta, - xtime.tv_sec - oldtime, - xtime.tv_nsec - (NSEC_PER_SEC >> 1)); + ts.tv_sec - oldtime, + ts.tv_nsec - (NSEC_PER_SEC >> 1)); return 0; } diff --git a/drivers/s390/net/ctcmain.c b/drivers/s390/net/ctcmain.c index b20fd0681733..92e8a37b5022 100644 --- a/drivers/s390/net/ctcmain.c +++ b/drivers/s390/net/ctcmain.c @@ -674,7 +674,7 @@ ch_action_txdone(fsm_instance * fi, int event, void *arg) int first = 1; int i; unsigned long duration; - struct timespec done_stamp = xtime; + struct timespec done_stamp = current_kernel_time(); DBF_TEXT(trace, 4, __FUNCTION__); @@ -730,7 +730,7 @@ ch_action_txdone(fsm_instance * fi, int event, void *arg) spin_unlock(&ch->collect_lock); ch->ccw[1].count = ch->trans_skb->len; fsm_addtimer(&ch->timer, CTC_TIMEOUT_5SEC, CH_EVENT_TIMER, ch); - ch->prof.send_stamp = xtime; + ch->prof.send_stamp = current_kernel_time(); rc = ccw_device_start(ch->cdev, &ch->ccw[0], (unsigned long) ch, 0xff, 0); ch->prof.doios_multi++; @@ -2281,7 +2281,7 @@ transmit_skb(struct channel *ch, struct sk_buff *skb) fsm_newstate(ch->fsm, CH_STATE_TX); fsm_addtimer(&ch->timer, CTC_TIMEOUT_5SEC, CH_EVENT_TIMER, ch); spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags); - ch->prof.send_stamp = xtime; + ch->prof.send_stamp = current_kernel_time(); rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx], (unsigned long) ch, 0xff, 0); spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags); diff --git a/drivers/s390/net/netiucv.c b/drivers/s390/net/netiucv.c index 3d28e1a5bf79..268889474339 100644 --- a/drivers/s390/net/netiucv.c +++ b/drivers/s390/net/netiucv.c @@ -753,7 +753,7 @@ static void conn_action_txdone(fsm_instance *fi, int event, void *arg) header.next = 0; memcpy(skb_put(conn->tx_buff, NETIUCV_HDRLEN), &header, NETIUCV_HDRLEN); - conn->prof.send_stamp = xtime; + conn->prof.send_stamp = current_kernel_time(); txmsg.class = 0; txmsg.tag = 0; rc = iucv_message_send(conn->path, &txmsg, 0, 0, @@ -1185,7 +1185,7 @@ static int netiucv_transmit_skb(struct iucv_connection *conn, memcpy(skb_put(nskb, NETIUCV_HDRLEN), &header, NETIUCV_HDRLEN); fsm_newstate(conn->fsm, CONN_STATE_TX); - conn->prof.send_stamp = xtime; + conn->prof.send_stamp = current_kernel_time(); msg.tag = 1; msg.class = 0; diff --git a/include/linux/time.h b/include/linux/time.h index e6aea5146e5d..71181df8b744 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -107,7 +107,7 @@ static inline unsigned long get_seconds(void) struct timespec current_kernel_time(void); #define CURRENT_TIME (current_kernel_time()) -#define CURRENT_TIME_SEC ((struct timespec) { xtime.tv_sec, 0 }) +#define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 }) extern void do_gettimeofday(struct timeval *tv); extern int do_settimeofday(struct timespec *tv); diff --git a/kernel/acct.c b/kernel/acct.c index 70d0d88e5554..24f0f8b2ba72 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -468,7 +468,7 @@ static void do_acct_process(struct file *file) } #endif do_div(elapsed, AHZ); - ac.ac_btime = xtime.tv_sec - elapsed; + ac.ac_btime = get_seconds() - elapsed; /* we really need to bite the bullet and change layout */ ac.ac_uid = current->uid; ac.ac_gid = current->gid; diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index eb1ddebd2c04..a7bb05e6cb63 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -144,7 +144,7 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) #ifdef CONFIG_NO_HZ getnstimeofday(&xts); #else - xts = xtime; + xts = current_kernel_time(); #endif tom = wall_to_monotonic; } while (read_seqretry(&xtime_lock, seq)); diff --git a/kernel/time.c b/kernel/time.c index 5b81da08bbdb..2289a8d68314 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -215,22 +215,6 @@ asmlinkage long sys_adjtimex(struct timex __user *txc_p) return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret; } -inline struct timespec current_kernel_time(void) -{ - struct timespec now; - unsigned long seq; - - do { - seq = read_seqbegin(&xtime_lock); - - now = xtime; - } while (read_seqretry(&xtime_lock, seq)); - - return now; -} - -EXPORT_SYMBOL(current_kernel_time); - /** * current_fs_time - Return FS time * @sb: Superblock. diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 88c81026e003..07a3f1420c27 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -509,3 +509,19 @@ void monotonic_to_bootbased(struct timespec *ts) { ts->tv_sec += total_sleep_time; } + +struct timespec current_kernel_time(void) +{ + struct timespec now; + unsigned long seq; + + do { + seq = read_seqbegin(&xtime_lock); + + now = xtime; + } while (read_seqretry(&xtime_lock, seq)); + + return now; +} + +EXPORT_SYMBOL(current_kernel_time); diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 658f638c402c..c122131a122f 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -39,7 +39,7 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) ac_etime = timespec_to_ns(&ts); do_div(ac_etime, NSEC_PER_USEC); stats->ac_etime = ac_etime; - stats->ac_btime = xtime.tv_sec - ts.tv_sec; + stats->ac_btime = get_seconds() - ts.tv_sec; if (thread_group_leader(tsk)) { stats->ac_exitcode = tsk->exit_code; if (tsk->flags & PF_FORKNOEXEC) diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 16a68df4e36b..c58fa0d1be26 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -787,7 +787,7 @@ static int __init af_rxrpc_init(void) BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > sizeof(dummy_skb->cb)); - rxrpc_epoch = htonl(xtime.tv_sec); + rxrpc_epoch = htonl(get_seconds()); ret = -ENOMEM; rxrpc_call_jar = kmem_cache_create( diff --git a/net/rxrpc/ar-connection.c b/net/rxrpc/ar-connection.c index 482750efc235..372b24466dc7 100644 --- a/net/rxrpc/ar-connection.c +++ b/net/rxrpc/ar-connection.c @@ -791,7 +791,7 @@ void rxrpc_put_connection(struct rxrpc_connection *conn) ASSERTCMP(atomic_read(&conn->usage), >, 0); - conn->put_time = xtime.tv_sec; + conn->put_time = get_seconds(); if (atomic_dec_and_test(&conn->usage)) { _debug("zombie"); rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0); @@ -835,7 +835,7 @@ void rxrpc_connection_reaper(struct work_struct *work) _enter(""); - now = xtime.tv_sec; + now = get_seconds(); earliest = ULONG_MAX; write_lock_bh(&rxrpc_connection_lock); diff --git a/net/rxrpc/ar-transport.c b/net/rxrpc/ar-transport.c index d43d78f19302..bb282a6a19f0 100644 --- a/net/rxrpc/ar-transport.c +++ b/net/rxrpc/ar-transport.c @@ -183,7 +183,7 @@ void rxrpc_put_transport(struct rxrpc_transport *trans) ASSERTCMP(atomic_read(&trans->usage), >, 0); - trans->put_time = xtime.tv_sec; + trans->put_time = get_seconds(); if (unlikely(atomic_dec_and_test(&trans->usage))) _debug("zombie"); /* let the reaper determine the timeout to avoid a race with @@ -219,7 +219,7 @@ static void rxrpc_transport_reaper(struct work_struct *work) _enter(""); - now = xtime.tv_sec; + now = get_seconds(); earliest = ULONG_MAX; /* extract all the transports that have been dead too long */ diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c index 5ec705144e10..ac3cabdca78c 100644 --- a/net/rxrpc/rxkad.c +++ b/net/rxrpc/rxkad.c @@ -916,7 +916,7 @@ static int rxkad_decrypt_ticket(struct rxrpc_connection *conn, issue = be32_to_cpu(stamp); } p += 4; - now = xtime.tv_sec; + now = get_seconds(); _debug("KIV ISSUE: %lx [%lx]", issue, now); /* check the ticket is in date */ -- cgit v1.3-14-g43fede From 17c38b7490b3f0300c7812aefdae2ddda7ab4112 Mon Sep 17 00:00:00 2001 From: john stultz Date: Tue, 24 Jul 2007 18:38:34 -0700 Subject: Cache xtime every call to update_wall_time This avoids xtime lag seen with dynticks, because while 'xtime' itself is still not updated often, we keep a 'xtime_cache' variable around that contains the approximate real-time that _is_ updated each time we do a 'update_wall_time()', and is thus never off by more than one tick. IOW, this restores the original semantics for 'xtime' users, as long as you use the proper abstraction functions (ie 'current_kernel_time()' or 'get_seconds()' depending on whether you want a timespec or just the seconds field). [ Updated Patch. As penance for my sins I've also yanked another #ifdef that was added to avoid the xtime lag w/ hrtimers. ] Signed-off-by: John Stultz Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Linus Torvalds --- include/linux/time.h | 6 +----- kernel/hrtimer.c | 4 ---- kernel/time/timekeeping.c | 26 +++++++++++++++++++++++--- 3 files changed, 24 insertions(+), 12 deletions(-) (limited to 'include/linux/time.h') diff --git a/include/linux/time.h b/include/linux/time.h index 71181df8b744..6a5f503b4f1d 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -99,11 +99,7 @@ extern int update_persistent_clock(struct timespec now); extern int no_sync_cmos_clock __read_mostly; void timekeeping_init(void); -static inline unsigned long get_seconds(void) -{ - return xtime.tv_sec; -} - +unsigned long get_seconds(void); struct timespec current_kernel_time(void); #define CURRENT_TIME (current_kernel_time()) diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index a7bb05e6cb63..c21ca6bfaa66 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -141,11 +141,7 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) do { seq = read_seqbegin(&xtime_lock); -#ifdef CONFIG_NO_HZ - getnstimeofday(&xts); -#else xts = current_kernel_time(); -#endif tom = wall_to_monotonic; } while (read_seqretry(&xtime_lock, seq)); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 07a3f1420c27..acc417b5a9b7 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -47,10 +47,22 @@ EXPORT_SYMBOL(xtime_lock); struct timespec xtime __attribute__ ((aligned (16))); struct timespec wall_to_monotonic __attribute__ ((aligned (16))); static unsigned long total_sleep_time; /* seconds */ - EXPORT_SYMBOL(xtime); +#ifdef CONFIG_NO_HZ +static struct timespec xtime_cache __attribute__ ((aligned (16))); +static inline void update_xtime_cache(u64 nsec) +{ + xtime_cache = xtime; + timespec_add_ns(&xtime_cache, nsec); +} +#else +#define xtime_cache xtime +/* We do *not* want to evaluate the argument for this case */ +#define update_xtime_cache(n) do { } while (0) +#endif + static struct clocksource *clock; /* pointer to current clocksource */ @@ -478,6 +490,8 @@ void update_wall_time(void) xtime.tv_nsec = (s64)clock->xtime_nsec >> clock->shift; clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift; + update_xtime_cache(cyc2ns(clock, offset)); + /* check to see if there is a new clocksource to use */ change_clocksource(); update_vsyscall(&xtime, clock); @@ -510,6 +524,13 @@ void monotonic_to_bootbased(struct timespec *ts) ts->tv_sec += total_sleep_time; } +unsigned long get_seconds(void) +{ + return xtime_cache.tv_sec; +} +EXPORT_SYMBOL(get_seconds); + + struct timespec current_kernel_time(void) { struct timespec now; @@ -518,10 +539,9 @@ 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; } - EXPORT_SYMBOL(current_kernel_time); -- cgit v1.3-14-g43fede