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| author | john stultz <johnstul@us.ibm.com> | 2007-02-16 01:27:26 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-16 08:13:56 -0800 |
| commit | f4304ab21513b834c8fe3403927c60c2b81a72d7 (patch) | |
| tree | 212c8fa327d9cf3f29cccf172f0707a3eb6524f8 /kernel/time | |
| parent | 771ee3b04eaac6184312825eb600b4c598f027a5 (diff) | |
| download | linux-f4304ab21513b834c8fe3403927c60c2b81a72d7.tar.gz linux-f4304ab21513b834c8fe3403927c60c2b81a72d7.tar.bz2 linux-f4304ab21513b834c8fe3403927c60c2b81a72d7.zip | |
[PATCH] HZ free ntp
Distangle the NTP update from HZ. This is necessary for dynamic tick enabled
kernels.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/ntp.c | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 3afeaa3a73f9..eb12509e00bd 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -24,7 +24,7 @@ static u64 tick_length, tick_length_base; #define MAX_TICKADJ 500 /* microsecs */ #define MAX_TICKADJ_SCALED (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \ - TICK_LENGTH_SHIFT) / HZ) + TICK_LENGTH_SHIFT) / NTP_INTERVAL_FREQ) /* * phase-lock loop variables @@ -46,13 +46,17 @@ long time_adjust; static void ntp_update_frequency(void) { - tick_length_base = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << TICK_LENGTH_SHIFT; - tick_length_base += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT; - tick_length_base += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC); + 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)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC); - do_div(tick_length_base, HZ); + tick_length_base = second_length; - tick_nsec = tick_length_base >> TICK_LENGTH_SHIFT; + do_div(second_length, HZ); + tick_nsec = second_length >> TICK_LENGTH_SHIFT; + + do_div(tick_length_base, NTP_INTERVAL_FREQ); } /** @@ -162,7 +166,7 @@ void second_overflow(void) tick_length -= MAX_TICKADJ_SCALED; } else { tick_length += (s64)(time_adjust * NSEC_PER_USEC / - HZ) << TICK_LENGTH_SHIFT; + NTP_INTERVAL_FREQ) << TICK_LENGTH_SHIFT; time_adjust = 0; } } @@ -239,7 +243,8 @@ int do_adjtimex(struct timex *txc) result = -EINVAL; goto leave; } - time_freq = ((s64)txc->freq * NSEC_PER_USEC) >> (SHIFT_USEC - SHIFT_NSEC); + time_freq = ((s64)txc->freq * NSEC_PER_USEC) + >> (SHIFT_USEC - SHIFT_NSEC); } if (txc->modes & ADJ_MAXERROR) { @@ -309,7 +314,8 @@ int do_adjtimex(struct timex *txc) freq_adj += time_freq; freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC); time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC); - time_offset = (time_offset / HZ) << SHIFT_UPDATE; + time_offset = (time_offset / NTP_INTERVAL_FREQ) + << SHIFT_UPDATE; } /* STA_PLL */ } /* txc->modes & ADJ_OFFSET */ if (txc->modes & ADJ_TICK) @@ -324,8 +330,10 @@ leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0) if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) txc->offset = save_adjust; else - txc->offset = shift_right(time_offset, SHIFT_UPDATE) * HZ / 1000; - txc->freq = (time_freq / NSEC_PER_USEC) << (SHIFT_USEC - SHIFT_NSEC); + txc->offset = shift_right(time_offset, SHIFT_UPDATE) + * NTP_INTERVAL_FREQ / 1000; + txc->freq = (time_freq / NSEC_PER_USEC) + << (SHIFT_USEC - SHIFT_NSEC); txc->maxerror = time_maxerror; txc->esterror = time_esterror; txc->status = time_status; |