Cleanup non-arch xtime uses, use get_seconds() or current_kernel_time().
john stultz [Wed, 25 Jul 2007 00:47:43 +0000 (17:47 -0700)]
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 <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

13 files changed:
drivers/rtc/class.c
drivers/s390/net/ctcmain.c
drivers/s390/net/netiucv.c
include/linux/time.h
kernel/acct.c
kernel/hrtimer.c
kernel/time.c
kernel/time/timekeeping.c
kernel/tsacct.c
net/rxrpc/af_rxrpc.c
net/rxrpc/ar-connection.c
net/rxrpc/ar-transport.c
net/rxrpc/rxkad.c

index 8b3cd31..10ab3b7 100644 (file)
@@ -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;
 }
index b20fd06..92e8a37 100644 (file)
@@ -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);
index 3d28e1a..2688894 100644 (file)
@@ -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;
index e6aea51..71181df 100644 (file)
@@ -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);
index 70d0d88..24f0f8b 100644 (file)
@@ -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;
index eb1ddeb..a7bb05e 100644 (file)
@@ -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));
index 5b81da0..2289a8d 100644 (file)
@@ -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.
index 88c8102..07a3f14 100644 (file)
@@ -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);
index 658f638..c122131 100644 (file)
@@ -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)
index 16a68df..c58fa0d 100644 (file)
@@ -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(
index 482750e..372b244 100644 (file)
@@ -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);
index d43d78f..bb282a6 100644 (file)
@@ -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 */
index 5ec7051..ac3cabd 100644 (file)
@@ -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 */