diff options
Diffstat (limited to 'kernel/timer.c')
| -rw-r--r-- | kernel/timer.c | 252 |
1 files changed, 126 insertions, 126 deletions
diff --git a/kernel/timer.c b/kernel/timer.c index 6b94adb45b03..cc18857601e2 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -632,77 +632,74 @@ long time_next_adjust; */ static void second_overflow(void) { - long ltemp; - - /* Bump the maxerror field */ - time_maxerror += time_tolerance >> SHIFT_USEC; - if ( time_maxerror > NTP_PHASE_LIMIT ) { - time_maxerror = NTP_PHASE_LIMIT; - time_status |= STA_UNSYNC; - } - - /* - * 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. The microtime() routine or - * external clock driver will insure that reported time - * is always monotonic. The ugly divides should be - * replaced. - */ - 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: - if (xtime.tv_sec % 86400 == 0) { - xtime.tv_sec--; - wall_to_monotonic.tv_sec++; - /* The timer interpolator will make time change gradually instead - * of an immediate jump by one second. - */ - time_interpolator_update(-NSEC_PER_SEC); - time_state = TIME_OOP; - clock_was_set(); - printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n"); + long ltemp; + + /* Bump the maxerror field */ + time_maxerror += time_tolerance >> SHIFT_USEC; + if (time_maxerror > NTP_PHASE_LIMIT) { + time_maxerror = NTP_PHASE_LIMIT; + time_status |= STA_UNSYNC; } - break; - - case TIME_DEL: - if ((xtime.tv_sec + 1) % 86400 == 0) { - xtime.tv_sec++; - wall_to_monotonic.tv_sec--; - /* Use of time interpolator for a gradual change of time */ - time_interpolator_update(NSEC_PER_SEC); - time_state = TIME_WAIT; - clock_was_set(); - printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n"); + + /* + * 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. The microtime() + * routine or external clock driver will insure that reported time is + * always monotonic. The ugly divides should be replaced. + */ + 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: + if (xtime.tv_sec % 86400 == 0) { + xtime.tv_sec--; + wall_to_monotonic.tv_sec++; + /* + * The timer interpolator will make time change + * gradually instead of an immediate jump by one second + */ + time_interpolator_update(-NSEC_PER_SEC); + time_state = TIME_OOP; + clock_was_set(); + printk(KERN_NOTICE "Clock: inserting leap second " + "23:59:60 UTC\n"); + } + break; + case TIME_DEL: + if ((xtime.tv_sec + 1) % 86400 == 0) { + xtime.tv_sec++; + wall_to_monotonic.tv_sec--; + /* + * Use of time interpolator for a gradual change of + * time + */ + time_interpolator_update(NSEC_PER_SEC); + time_state = TIME_WAIT; + clock_was_set(); + printk(KERN_NOTICE "Clock: deleting leap second " + "23:59:59 UTC\n"); + } + break; + case TIME_OOP: + time_state = TIME_WAIT; + break; + case TIME_WAIT: + if (!(time_status & (STA_INS | STA_DEL))) + time_state = TIME_OK; } - break; - - case TIME_OOP: - time_state = TIME_WAIT; - break; - - case TIME_WAIT: - if (!(time_status & (STA_INS | STA_DEL))) - time_state = TIME_OK; - } - - /* - * Compute the phase adjustment for the next second. In - * PLL mode, the offset is reduced by a fixed factor - * times the time constant. In FLL mode the offset is - * used directly. In either mode, the maximum phase - * adjustment for each second is clamped so as to spread - * the adjustment over not more than the number of - * seconds between updates. - */ + + /* + * Compute the phase adjustment for the next second. In PLL mode, the + * offset is reduced by a fixed factor times the time constant. In FLL + * mode the offset is used directly. In either mode, the maximum phase + * adjustment for each second is clamped so as to spread the adjustment + * over not more than the number of seconds between updates. + */ ltemp = time_offset; if (!(time_status & STA_FLL)) ltemp = shift_right(ltemp, SHIFT_KG + time_constant); @@ -711,40 +708,42 @@ static void second_overflow(void) time_offset -= ltemp; time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); - /* - * Compute the frequency estimate and additional phase - * adjustment due to frequency error for the next - * second. When the PPS signal is engaged, gnaw on the - * watchdog counter and update the frequency computed by - * the pll and the PPS signal. - */ - pps_valid++; - if (pps_valid == PPS_VALID) { /* PPS signal lost */ - pps_jitter = MAXTIME; - pps_stabil = MAXFREQ; - time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER | - STA_PPSWANDER | STA_PPSERROR); - } - ltemp = time_freq + pps_freq; - time_adj += shift_right(ltemp,(SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE)); + /* + * Compute the frequency estimate and additional phase adjustment due + * to frequency error for the next second. When the PPS signal is + * engaged, gnaw on the watchdog counter and update the frequency + * computed by the pll and the PPS signal. + */ + pps_valid++; + if (pps_valid == PPS_VALID) { /* PPS signal lost */ + pps_jitter = MAXTIME; + pps_stabil = MAXFREQ; + time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER | + STA_PPSWANDER | STA_PPSERROR); + } + ltemp = time_freq + pps_freq; + time_adj += shift_right(ltemp,(SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE)); #if HZ == 100 - /* Compensate for (HZ==100) != (1 << SHIFT_HZ). - * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14) - */ - time_adj += shift_right(time_adj, 2) + shift_right(time_adj, 5); + /* + * Compensate for (HZ==100) != (1 << SHIFT_HZ). Add 25% and 3.125% to + * get 128.125; => only 0.125% error (p. 14) + */ + time_adj += shift_right(time_adj, 2) + shift_right(time_adj, 5); #endif #if HZ == 250 - /* Compensate for (HZ==250) != (1 << SHIFT_HZ). - * Add 1.5625% and 0.78125% to get 255.85938; => only 0.05% error (p. 14) - */ - time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7); + /* + * Compensate for (HZ==250) != (1 << SHIFT_HZ). Add 1.5625% and + * 0.78125% to get 255.85938; => only 0.05% error (p. 14) + */ + time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7); #endif #if HZ == 1000 - /* Compensate for (HZ==1000) != (1 << SHIFT_HZ). - * Add 1.5625% and 0.78125% to get 1023.4375; => only 0.05% error (p. 14) - */ - time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7); + /* + * Compensate for (HZ==1000) != (1 << SHIFT_HZ). Add 1.5625% and + * 0.78125% to get 1023.4375; => only 0.05% error (p. 14) + */ + time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7); #endif } @@ -753,21 +752,20 @@ static void update_wall_time_one_tick(void) { long time_adjust_step, delta_nsec; - if ( (time_adjust_step = time_adjust) != 0 ) { - /* We are doing an adjtime thing. - * - * Prepare time_adjust_step to be within bounds. - * Note that a positive time_adjust means we want the clock - * to run faster. - * - * Limit the amount of the step to be in the range - * -tickadj .. +tickadj - */ - time_adjust_step = min(time_adjust_step, (long)tickadj); - time_adjust_step = max(time_adjust_step, (long)-tickadj); - - /* Reduce by this step the amount of time left */ - time_adjust -= time_adjust_step; + if ((time_adjust_step = time_adjust) != 0 ) { + /* + * We are doing an adjtime thing. Prepare time_adjust_step to + * be within bounds. Note that a positive time_adjust means we + * want the clock to run faster. + * + * Limit the amount of the step to be in the range + * -tickadj .. +tickadj + */ + time_adjust_step = min(time_adjust_step, (long)tickadj); + time_adjust_step = max(time_adjust_step, (long)-tickadj); + + /* Reduce by this step the amount of time left */ + time_adjust -= time_adjust_step; } delta_nsec = tick_nsec + time_adjust_step * 1000; /* @@ -1106,8 +1104,8 @@ fastcall signed long __sched schedule_timeout(signed long timeout) if (timeout < 0) { printk(KERN_ERR "schedule_timeout: wrong timeout " - "value %lx from %p\n", timeout, - __builtin_return_address(0)); + "value %lx from %p\n", timeout, + __builtin_return_address(0)); current->state = TASK_RUNNING; goto out; } @@ -1133,15 +1131,15 @@ EXPORT_SYMBOL(schedule_timeout); */ signed long __sched schedule_timeout_interruptible(signed long timeout) { - __set_current_state(TASK_INTERRUPTIBLE); - return schedule_timeout(timeout); + __set_current_state(TASK_INTERRUPTIBLE); + return schedule_timeout(timeout); } EXPORT_SYMBOL(schedule_timeout_interruptible); signed long __sched schedule_timeout_uninterruptible(signed long timeout) { - __set_current_state(TASK_UNINTERRUPTIBLE); - return schedule_timeout(timeout); + __set_current_state(TASK_UNINTERRUPTIBLE); + return schedule_timeout(timeout); } EXPORT_SYMBOL(schedule_timeout_uninterruptible); @@ -1481,16 +1479,18 @@ static void time_interpolator_update(long delta_nsec) if (!time_interpolator) return; - /* The interpolator compensates for late ticks by accumulating - * the late time in time_interpolator->offset. A tick earlier than - * expected will lead to a reset of the offset and a corresponding - * jump of the clock forward. Again this only works if the - * interpolator clock is running slightly slower than the regular clock - * and the tuning logic insures that. - */ + /* + * The interpolator compensates for late ticks by accumulating the late + * time in time_interpolator->offset. A tick earlier than expected will + * lead to a reset of the offset and a corresponding jump of the clock + * forward. Again this only works if the interpolator clock is running + * slightly slower than the regular clock and the tuning logic insures + * that. + */ counter = time_interpolator_get_counter(1); - offset = time_interpolator->offset + GET_TI_NSECS(counter, time_interpolator); + offset = time_interpolator->offset + + GET_TI_NSECS(counter, time_interpolator); if (delta_nsec < 0 || (unsigned long) delta_nsec < offset) time_interpolator->offset = offset - delta_nsec; |