linux-toradex.git/include/linux/time.h, branch v2.6.27.50

sched_clock: prevent scd->clock from moving backwards, take #2

2009-01-18T18:35:28+00:00

commit 1c5745aa380efb6417b5681104b007c8612fb496 upstream.

Redo:

  5b7dba4: sched_clock: prevent scd->clock from moving backwards

which had to be reverted due to s2ram hangs:

  ca7e716: Revert "sched_clock: prevent scd->clock from moving backwards"

... this time with resume restoring GTOD later in the sequence
taken into account as well.

The "timekeeping_suspended" flag is not very nice but we cannot call into
GTOD before it has been properly resumed and the scheduler will run very
early in the resume sequence.

Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

always_inline timespec_add_ns

2008-06-12T08:48:00+00:00

timespec_add_ns is used from the x86-64 vdso, which cannot call out to
other kernel code.  Make sure that timespec_add_ns is always inlined
(and only uses always_inlined functions) to make sure there are no
unexpected calls.

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar

common implementation of iterative div/mod

2008-06-12T08:47:56+00:00

We have a few instances of the open-coded iterative div/mod loop, used
when we don't expcet the dividend to be much bigger than the divisor.
Unfortunately modern gcc's have the tendency to strength "reduce" this
into a full mod operation, which isn't necessarily any faster, and
even if it were, doesn't exist if gcc implements it in libgcc.

The workaround is to put a dummy asm statement in the loop to prevent
gcc from performing the transformation.

This patch creates a single implementation of this loop, and uses it
to replace the open-coded versions I know about.

Signed-off-by: Jeremy Fitzhardinge 
Cc: Andrew Morton 
Cc: john stultz 
Cc: Segher Boessenkool 
Cc: Christian Kujau 
Cc: Robert Hancock 
Signed-off-by: Ingo Molnar

time: prevent the loop in timespec_add_ns() from being optimised away

2008-03-09T07:42:57+00:00

Since some architectures don't support __udivdi3().

Signed-off-by: Segher Boessenkool 
Cc: john stultz 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

timekeeping: rename timekeeping_is_continuous to timekeeping_valid_for_hres

2008-02-08T17:22:29+00:00

Function timekeeping_is_continuous() no longer checks flag
CLOCK_IS_CONTINUOUS, and it checks CLOCK_SOURCE_VALID_FOR_HRES now.  So rename
the function accordingly.

Signed-off-by: Li Zefan 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

timekeeping: update xtime_cache when time(zone) changes

2008-02-01T16:45:13+00:00

xtime_cache needs to be updated whenever xtime and or wall_to_monotic
are changed. Otherwise users of xtime_cache might see a stale (and in
the case of timezone changes utterly wrong) value until the next
update happens.

Fixup the obvious places, which miss this update.

Signed-off-by: Thomas Gleixner 
Acked-by: John Stultz 
Tested-by: Dhaval Giani 
Signed-off-by: Ingo Molnar

kernel/time/timekeeping.c: cleanups

2007-10-17T15:42:53+00:00

- remove the no longer required __attribute__((weak)) of xtime_lock
- remove the following no longer used EXPORT_SYMBOL's:
  - xtime
  - xtime_lock

Signed-off-by: Adrian Bunk 
Cc: Thomas Gleixner 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Cache xtime every call to update_wall_time

2007-07-25T17:17:44+00:00

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

Cleanup non-arch xtime uses, use get_seconds() or current_kernel_time().

2007-07-25T17:09:20+00:00

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

NTP: move the cmos update code into ntp.c

2007-07-22T00:49:15+00:00

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