The time_status conditional was accidentally placed right after we clear
the checked time_status bits, which causes us to take the conditional
every time through. This fixes it by moving the conditional to before we
clear the time_status bits.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Clark Williams <williams@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
The 'time_adj' local variable is named in a very confusing
way because it almost shadows the 'time_adjust' global
variable - which is used in this same function.
Rename it to 'delta' - to make them stand apart more clearly.
kernel/time/ntp.o:
text data bss dec hex filename
2545 114 144 2803 af3 ntp.o.before
2545 114 144 2803 af3 ntp.o.after
md5:
1bf0b3be564512279ba7cee299d1d2be ntp.o.before.asm
1bf0b3be564512279ba7cee299d1d2be ntp.o.after.asm
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: micro-optimization
Convert the (internal) ntp_tick_adj value we store from unscaled
units to scaled units. This is a constant that we never modify,
so scaling it up once during bootup is enough - we dont have to
do it for every adjustment step.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
Further simplify do_adjtimex():
- introduce the ntp_start_leap_timer() helper function
- eliminate the goto adj_done complication
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
do_adjtimex() is currently a monster function with a maze of
branches. Refactor the txc->modes setting aspects of it into
two new helper functions:
process_adj_status()
process_adjtimex_modes()
kernel/time/ntp.o:
text data bss dec hex filename
2512 114 136 2762 aca ntp.o.before
2512 114 136 2762 aca ntp.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: change (fix) the way the NTP PLL seconds offset is initialized/tracked
Fix a bug and do a micro-optimization:
When PLL is enabled we do not reset time_reftime. If the PLL
was off for a long time (for example after bootup), this is
arguably the wrong thing to do.
We already had a hack for the common boot-time case in
ntp_update_offset(), in form of:
if (unlikely(time_status & STA_FREQHOLD || time_reftime == 0))
secs = 0;
But the update delta should be reset later on too - not just when
the PLL is enabled for the first time after bootup.
So do it on !STA_PLL -> STA_PLL transitions.
This changes behavior, as previously if ntpd was disabled for
a long time and we restarted it, we'd run from that last update,
with a very large delta.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
The time_reftime update in ntp_update_offset() to xtime.tv_sec
is a convoluted way of saying that we want to freeze the frequency
and want the 'secs' delta to be 0. Also make this branch unlikely.
This shaves off 8 bytes from the code size:
text data bss dec hex filename
2504 114 136 2754 ac2 ntp.o.before
2496 114 136 2746 aba ntp.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
Change ntp_update_offset_fll() to delta logic instead of
absolute value logic. This eliminates 'freq_adj' from the
function.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
Change ntp_update_frequency() from a hard to follow code
flow that uses global variables as temporaries, to a clean
input+output flow.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
There's an ugly u64 typecase in the MAX_TICKADJ_SCALED definition,
this can be eliminated by making the MAX_TICKADJ constant's type
64-bit (signed).
kernel/time/ntp.o:
text data bss dec hex filename
2504 114 136 2754 ac2 ntp.o.before
2504 114 136 2754 ac2 ntp.o.after
md5:
41f3009debc9b397d7394dd77d912f0a ntp.o.before.asm
41f3009debc9b397d7394dd77d912f0a ntp.o.after.asm
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
Instead of a hierarchy of conditions, transform them to clean
gradual conditions and return's.
This makes the flow easier to read and makes the purpose of
the function easier to understand.
kernel/time/ntp.o:
text data bss dec hex filename
2552 170 168 2890 b4a ntp.o.before
2552 170 168 2890 b4a ntp.o.after
md5:
eae1275df0b7d6290c13f6f6f8f05c8c ntp.o.before.asm
eae1275df0b7d6290c13f6f6f8f05c8c ntp.o.after.asm
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, no functionality changed
Make this file a bit more readable by applying a consistent coding style.
No code changed:
kernel/time/ntp.o:
text data bss dec hex filename
2552 170 168 2890 b4a ntp.o.before
2552 170 168 2890 b4a ntp.o.after
md5:
eae1275df0b7d6290c13f6f6f8f05c8c ntp.o.before.asm
eae1275df0b7d6290c13f6f6f8f05c8c ntp.o.after.asm
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since the GENERIC_TIME changes landed, the adjtimex behavior changed
for struct timex.tick and .freq changed. When the tick or freq value
is set, we adjust the tick_length_base in ntp_update_frequency().
However, this new value doesn't get applied to tick_length until the
next second (via second_overflow).
This means some applications that do quick time tweaking do not see the
requested change made as quickly as expected.
I've run a few tests with this change, and ntpd still functions fine.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, move all hrtimer processing into hardirq context
This is an attempt at removing some of the hrtimer complexity by
reducing the number of callback modes to 1.
This means that all hrtimer callback functions will be ran from HARD-irq
context.
I went through all the 30 odd hrtimer callback functions in the kernel
and saw only one that I'm not quite sure of, which is the one in
net/can/bcm.c - hence I'm CC-ing the folks responsible for that code.
Furthermore, the hrtimer core now calls callbacks directly with IRQs
disabled in case you try to enqueue an expired timer. If this timer is a
periodic timer (which should use hrtimer_forward() to advance its time)
then it might be possible to end up in an inf. recursive loop due to the
fact that hrtimer_forward() doesn't round up to the next timer
granularity, and therefore keeps on calling the callback - obviously
this needs a fix.
Aside from that, this seems to compile and actually boot on my dual core
test box - although I'm sure there are some bugs in, me not hitting any
makes me certain :-)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change PPM_SCALE_INV_SHIFT so that it doesn't throw away any input bits
(19 is the amount of the factor 2 in PPM_SCALE), the output frequency
can then be calculated back to its input value, as the inverse divide
produce a slightly larger value, which is then correctly rounded by the
final shift.
Reported-by: Martin Ziegler <ziegler@uni-freiburg.de>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This is a change that makes the 11-minute RTC update be run in the process
context. This is so that update_persistent_clock() can sleep, which may
be required for certain types of RTC hardware -- most notably I2C devices.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Brownell <david-b@pacbell.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
