linux-toradex.git/kernel/time/ntp.c, branch v2.6.23.12

ntp: fix typo that makes sync_cmos_clock erratic

2007-11-26T17:42:32+00:00

patch fa6a1a554b50cbb7763f6907e6fef927ead480d9 in mainline.

ntp: fix typo that makes sync_cmos_clock erratic

Fix a typo in ntp.c that has caused updating of the persistent (RTC)
clock when synced to NTP to behave erratically.

When debugging a freeze that arises on my AMD64 machines when I
run the ntpd service, I added a number of printk's to monitor the
sync_cmos_clock procedure.  I discovered that it was not syncing to
cmos RTC every 11 minutes as documented, but instead would keep trying
every second for hours at a time.  The reason turned out to be a typo
in sync_cmos_clock, where it attempts to ensure that
update_persistent_clock is called very close to 500 msec. after a 1
second boundary (required by the PC RTC's spec). That typo referred to
"xtime" in one spot, rather than "now", which is derived from "xtime"
but not equal to it.  This makes the test erratic, creating a
"coin-flip" that decides when update_persistent_clock is called - when
it is called, which is rarely, it may be at any time during the one
second period, rather than close to 500 msec, so the value written is
needlessly incorrect, too.

Signed-off-by: David P. Reed 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

Fix "no_sync_cmos_clock" logic inversion in kernel/time/ntp.c

2007-09-12T00:21:27+00:00

Seems to me that this timer will only get started on platforms that say
they don't want it?

Signed-off-by: Tony Breeds 
Cc: Paul Mackerras 
Cc: Gabriel Paubert 
Cc: Zachary Amsden 
Acked-by: Thomas Gleixner 
Cc: John Stultz 
Signed-off-by: Andrew Morton 
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

[IA64] remove time interpolator

2007-07-20T18:23:02+00:00

Remove time_interpolator code (This is generic code, but
only user was ia64.  It has been superseded by the
CONFIG_GENERIC_TIME code).

Signed-off-by: Bob Picco 
Signed-off-by: John Stultz 
Signed-off-by: Peter Keilty 
Signed-off-by: Tony Luck

Remove capability.h from mm.h

2007-07-16T16:05:45+00:00

I forgot to remove capability.h from mm.h while removing sched.h!  This
patch remedies that, because the only inline function which was using
CAP_something was made out of line.

Cross-compile tested without regressions on:

	all powerpc defconfigs
	all mips defconfigs
	all m68k defconfigs
	all arm defconfigs
	all ia64 defconfigs

	alpha alpha-allnoconfig alpha-defconfig alpha-up
	arm
	i386 i386-allnoconfig i386-defconfig i386-up
	ia64 ia64-allnoconfig ia64-defconfig ia64-up
	m68k
	mips
	parisc parisc-allnoconfig parisc-defconfig parisc-up
	powerpc powerpc-up
	s390 s390-allnoconfig s390-defconfig s390-up
	sparc sparc-allnoconfig sparc-defconfig sparc-up
	sparc64 sparc64-allnoconfig sparc64-defconfig sparc64-up
	um-x86_64
	x86_64 x86_64-allnoconfig x86_64-defconfig x86_64-up

as well as my two usual configs.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

NTP: remove clock_was_set() call to prevent deadlock

2007-07-03T20:54:27+00:00

The clock_was_set() call in seconds_overflow() which happens only when
leap seconds are inserted / deleted is wrong in two aspects:

1. it results in a call to on_each_cpu() with interrupts disabled
2. it is potential deadlock source vs. call_lock in smp_call_function()

The only possible side effect of the removal might be, that an absolute
CLOCK_REALTIME timer fires 1 second too late, in the rare case of leap
second deletion and an absolute CLOCK_REALTIME timer which expires in
the affected time frame. It will never fire too early.

This was probably observed by the reporter of a June 30th -> July 1st
hang: http://lkml.org/lkml/2007/7/3/103

A similar problem was observed by Dave Jones, who provided a screen shot
with a lockdep back trace, which allowed to analyse the problem.

Signed-off-by: Thomas Gleixner 
Acked-by: Ingo Molnar 
Signed-off-by: Linus Torvalds

Detach sched.h from mm.h

2007-05-21T16:18:19+00:00

First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

[PATCH] ntp: avoid time_offset overflows

2007-03-27T16:05:15+00:00

I've been seeing some odd NTP behavior recently on a few boxes and
finally narrowed it down to time_offset overflowing when converted to
SHIFT_UPDATE units (which was a side effect from my HZfreeNTP patch).

This patch converts time_offset from a long to a s64 which resolves the
issue.

[tglx@linutronix.de: signedness fixes]
Signed-off-by: John Stultz 
Cc: Roman Zippel 
Cc: john stultz 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] HZ free ntp

2007-02-16T16:13:56+00:00

Distangle the NTP update from HZ.  This is necessary for dynamic tick enabled
kernels.

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

[PATCH] time_adjust cleared before use

2006-10-28T18:30:55+00:00

I notice that the code which implements adjtime clears the time_adjust
value before using it.  The attached patch makes the obvious fix.

Acked-by: Roman Zippel 
Signed-off-by: Jim Houston 
Cc: John Stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds