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2008-05-01ntp: handle leap second via timerRoman Zippel
Remove the leap second handling from second_overflow(), which doesn't have to check for it every second anymore. With CONFIG_NO_HZ this also makes sure the leap second is handled close to the full second. Additionally this makes it possible to abort a leap second properly by resetting the STA_INS/STA_DEL status bits. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01ntp: remove current_tick_length()Roman Zippel
current_tick_length used to do a little more, but now it just returns tick_length, which we can also access directly at the few places, where it's needed. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01ntp: rename TICK_LENGTH_SHIFT to NTP_SCALE_SHIFTRoman Zippel
As TICK_LENGTH_SHIFT is used for more than just the tick length, the name isn't quite approriate anymore, so this renames it to NTP_SCALE_SHIFT. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01ntp: support for TAIRoman Zippel
This adds support for setting the TAI value (International Atomic Time). The value is reported back to userspace via timex (as we don't have a ntp_gettime() syscall). Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01ntp: increase time_offset resolutionRoman Zippel
time_offset is already a 64bit value but its resolution barely used, so this makes better use of it by replacing SHIFT_UPDATE with TICK_LENGTH_SHIFT. Side note: the SHIFT_HZ in SHIFT_UPDATE was incorrect for CONFIG_NO_HZ and the primary reason for changing time_offset to 64bit to avoid the overflow. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01ntp: increase time_freq resolutionRoman Zippel
This changes time_freq to a 64bit value and makes it static (the only outside user had no real need to modify it). Intermediate values were already 64bit, so the change isn't that big, but it saves a little in shifts by replacing SHIFT_NSEC with TICK_LENGTH_SHIFT. PPM_SCALE is then used to convert between user space and kernel space representation. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01ntp: NTP4 user space bits updateRoman Zippel
This adds a few more things from the ntp nanokernel related to user space. It's now possible to select the resolution used of some values via STA_NANO and the kernel reports in which mode it works (pll/fll). If some values for adjtimex() are outside the acceptable range, they are now simply normalized instead of letting the syscall fail. I removed MOD_CLKA/MOD_CLKB as the mapping didn't really makes any sense, the kernel doesn't support setting the clock. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01ntp: cleanup ntp.cRoman Zippel
This is mostly a style cleanup of ntp.c and extracts part of do_adjtimex as ntp_update_offset(). Otherwise the functionality is still the same as before. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01remove div_long_long_remRoman Zippel
x86 is the only arch right now, which provides an optimized for div_long_long_rem and it has the downside that one has to be very careful that the divide doesn't overflow. The API is a little akward, as the arguments for the unsigned divide are signed. The signed version also doesn't handle a negative divisor and produces worse code on 64bit archs. There is little incentive to keep this API alive, so this converts the few users to the new API. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01convert a few do_div usersRoman Zippel
This converts a few users of do_div to div_[su]64 and this demonstrates nicely how it can reduce some expressions to one-liners. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-09time: remove obsolete CLOCK_TICK_ADJUSTRoman Zippel
The first version of the ntp_interval/tick_length inconsistent usage patch was recently merged as bbe4d18ac2e058c56adb0cd71f49d9ed3216a405 http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bbe4d18ac2e058c56adb0cd71f49d9ed3216a405 While the fix did greatly improve the situation, it was correctly pointed out by Roman that it does have a small bug: If the users change clocksources after the system has been running and NTP has made corrections, the correctoins made against the old clocksource will be applied against the new clocksource, causing error. The second attempt, which corrects the issue in the NTP_INTERVAL_LENGTH definition has also made it up-stream as commit e13a2e61dd5152f5499d2003470acf9c838eab84 http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e13a2e61dd5152f5499d2003470acf9c838eab84 Roman has correctly pointed out that CLOCK_TICK_ADJUST is calculated based on the PIT's frequency, and isn't really relevant to non-PIT driven clocksources (that is, clocksources other then jiffies and pit). This patch reverts both of those changes, and simply removes CLOCK_TICK_ADJUST. This does remove the granularity error correction for users of PIT and Jiffies clocksource users, but the granularity error but for the majority of users, it should be within the 500ppm range NTP can accommodate for. For systems that have granularity errors greater then 500ppm, the "ntp_tick_adj=" boot option can be used to compensate. [johnstul@us.ibm.com: provided changelog] [mattilinnanvuori@yahoo.com: maek ntp_tick_adj static] Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Acked-by: john stultz <johnstul@us.ibm.com> Signed-off-by: Matti Linnanvuori <mattilinnanvuori@yahoo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: mingo@elte.hu Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-03-09ntp: use unsigned input for do_div()David Howells
The kernel NTP code shouldn't hand 64-bit *signed* values to do_div(). Make it instead hand 64-bit unsigned values. This gets rid of a couple of warnings. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-10ntp: correct inconsistent interval/tick_length usagejohn stultz
clocksource initialization and error accumulation. This corrects a 280ppm drift seen on some systems using acpi_pm, and affects other clocksources as well (likely to a lesser degree). Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-11-26time: add ADJ_OFFSET_SS_READJohn Stultz
Michael Kerrisk reported that a long standing bug in the adjtimex() system call causes glibc's adjtime(3) function to deliver the wrong results if 'delta' is NULL. add the ADJ_OFFSET_SS_READ API detail, which will be used by glibc to fix this API compatibility bug. Also see: http://bugzilla.kernel.org/show_bug.cgi?id=6761 [ mingo@elte.hu: added patch description and made it backwards compatible ] NOTE: the new flag is defined 0xa001 so that it returns -EINVAL on older kernels - this way glibc can use it safely. Suggested by Ulrich Drepper. Acked-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-11-17ntp: fix typo that makes sync_cmos_clock erraticDavid P. Reed
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 <tglx@linutronix.de>
2007-09-11Fix "no_sync_cmos_clock" logic inversion in kernel/time/ntp.cTony Breeds
Seems to me that this timer will only get started on platforms that say they don't want it? Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Gabriel Paubert <paubert@iram.es> Cc: Zachary Amsden <zach@vmware.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21NTP: move the cmos update code into ntp.cThomas Gleixner
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 <tglx@linutronix.de> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: David Miller <davem@davemloft.net> 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>
2007-07-20[IA64] remove time interpolatorBob Picco
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 <bob.picco@hp.com> Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Peter Keilty <peter.keilty@hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-07-16Remove capability.h from mm.hAlexey Dobriyan
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 <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-03NTP: remove clock_was_set() call to prevent deadlockThomas Gleixner
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 <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21Detach sched.h from mm.hAlexey Dobriyan
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 <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-27[PATCH] ntp: avoid time_offset overflowsjohn stultz
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 <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16[PATCH] HZ free ntpjohn stultz
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>
2006-10-28[PATCH] time_adjust cleared before useJim Houston
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 <zippel@linux-m68k.org> Signed-off-by: Jim Houston <jim.houston@ccur.com> Cc: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] kernel/time/ntp.c: possible cleanupsAdrian Bunk
This patch contains the following possible cleanups: - make the following needlessly global function static: - ntp_update_frequency() - make the following needlessly global variables static: - time_state - time_offset - time_constant - time_reftime - remove the following read-only global variable: - time_precision Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: convert to the NTP4 reference modelRoman Zippel
This converts the kernel ntp model into a model which matches the nanokernel reference implementations. The previous patches already increased the resolution and precision of the computations, so that this conversion becomes quite simple. <linux@horizon.com> explains: The original NTP kernel interface was defined in units of microseconds. That's what Linux implements. As computers have gotten faster and can now split microseconds easily, a new kernel interface using nanosecond units was defined ("the nanokernel", confusing as that name is to OS hackers), and there's an STA_NANO bit in the adjtimex() status field to tell the application which units it's using. The current ntpd supports both, but Linux loses some possible timing resolution because of quantization effects, and the ntpd hackers would really like to be able to drop the backwards compatibility code. Ulrich Windl has been maintaining a patch set to do the conversion for years, but it's hard to keep in sync. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: convert time_freq to nsec valueRoman Zippel
This converts time_freq to a scaled nsec value and adds around 6bit of extra resolution. This pushes the time_freq to its 32bit limits so the calculatons have to be done with 64bit. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: remove time_toleranceRoman Zippel
time_tolerance isn't changed at all in the kernel, so simply remove it, this simplifies the next patch, as it avoids a number of conversions. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: add time_adjust to tick lengthRoman Zippel
This folds update_ntp_one_tick() into second_overflow() and adds time_adjust to the tick length, this makes time_next_adjust unnecessary. This slightly changes the adjtime() behaviour, instead of applying it to the next tick, it's applied to the next second. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: prescale time_offsetRoman Zippel
This converts time_offset into a scaled per tick value. This avoids now completely the crude compensation in second_overflow(). Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: add time_freq to tick lengthRoman Zippel
This adds the frequency part to ntp_update_frequency(). Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: add time_adj to tick lengthRoman Zippel
This makes time_adj local to second_overflow() and integrates it into the tick length instead of adding it everytime. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: add ntp_update_frequencyRoman Zippel
This introduces ntp_update_frequency() and deinlines ntp_clear() (as it's not performance critical). ntp_update_frequency() calculates the base tick length using tick_usec and adds a base adjustment, in case the frequency doesn't divide evenly by HZ. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] NTP: Move all the NTP related code to ntp.cjohn stultz
Move all the NTP related code to ntp.c [akpm@osdl.org: cleanups, build fix] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>