linux/kernel/time/timekeeping.c, branch v2.6.38

Merge branches 'core-fixes-for-linus', 'x86-fixes-for-linus', 'timers-fixes-for-linus' and 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-01-15T20:45:00Z

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: avoid pointless blocked-task warnings rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status rtmutex: Fix comment about why new_owner can be NULL in wake_futex_pi() * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, olpc: Add missing Kconfig dependencies x86, mrst: Set correct APB timer IRQ affinity for secondary cpu x86: tsc: Fix calibration refinement conditionals to avoid divide by zero x86, ia64, acpi: Clean up x86-ism in drivers/acpi/numa.c * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timekeeping: Make local variables static time: Rename misnamed minsec argument of clocks_calc_mult_shift() * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: Remove syscall_exit_fields tracing: Only process module tracepoints once perf record: Add "nodelay" mode, disabled by default perf sched: Fix list of events, dropping unsupported ':r' modifier Revert "perf tools: Emit clearer message for sys_perf_event_open ENOENT return" perf top: Fix annotate segv perf evsel: Fix order of event list deletion

pps: capture MONOTONIC_RAW timestamps as well

2011-01-13T16:03:21Z

MONOTONIC_RAW clock timestamps are ideally suited for frequency calculation and also fit well into the original NTP hardpps design. Now phase and frequency can be adjusted separately: the former based on REALTIME clock and the latter based on MONOTONIC_RAW clock. A new function getnstime_raw_and_real is added to timekeeping subsystem to capture both timestamps at the same time and atomically. Signed-off-by: Alexander Gordeev Acked-by: John Stultz Cc: Rodolfo Giometti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

timekeeping: Make local variables static

2011-01-12T11:23:13Z

Signed-off-by: H Hartley Sweeten Cc: John Stultz LKML-Reference: <0D753D10438DA54287A00B027084269764CE0E54B7@AUSP01VMBX24.collaborationhost.net> Signed-off-by: Thomas Gleixner

time: Compensate for rounding on odd-frequency clocksources

2010-10-21T15:30:05Z

When the clocksource is not a multiple of HZ, the clock will be off. For acpi_pm, HZ=1000 the error is 127.111 ppm: The rounding of cycle_interval ends up generating a false error term in ntp_error accumulation since xtime_interval is not exactly 1/HZ. So, we subtract out the error caused by the rounding. This has been visible since 2.6.32-rc2 commit a092ff0f90cae22b2ac8028ecd2c6f6c1a9e4601 time: Implement logarithmic time accumulation That commit raised NTP_INTERVAL_FREQ and exposed the rounding error. testing tool: http://n1.taur.dk/permanent/testpmt.c Also tested with ntpd and a frequency counter. Signed-off-by: Kasper Pedersen Acked-by: john stultz Cc: John Kacur Cc: Clark Williams Cc: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner

time: Workaround gcc loop optimization that causes 64bit div errors

2010-08-13T19:03:24Z

Early 4.3 versions of gcc apparently aggressively optimize the raw time accumulation loop, replacing it with a divide. On 32bit systems, this causes the following link errors: undefined reference to `__umoddi3' undefined reference to `__udivdi3' The gcc issue has been fixed in 4.4 and greater. This patch replaces the accumulation loop with a do_div, as suggested by Linus. Signed-off-by: John Stultz CC: Jason Wessel CC: Larry Finger CC: Ingo Molnar CC: Linus Torvalds Signed-off-by: Linus Torvalds

timekeeping: Fix overflow in rawtime tv_nsec on 32 bit archs

2010-08-12T16:53:39Z

The tv_nsec is a long and when added to the shifted interval it can wrap and become negative which later causes looping problems in the getrawmonotonic(). The edge case occurs when the system has slept for a short period of time of ~2 seconds. A trace printk of the values in this patch illustrate the problem: ftrace time stamp: log 43.716079: logarithmic_accumulation: raw: 3d0913 tv_nsec d687faa 43.718513: logarithmic_accumulation: raw: 3d0913 tv_nsec da588bd 43.722161: logarithmic_accumulation: raw: 3d0913 tv_nsec de291d0 46.349925: logarithmic_accumulation: raw: 7a122600 tv_nsec e1f9ae3 46.349930: logarithmic_accumulation: raw: 1e848980 tv_nsec 8831c0e3 The kernel starts looping at 46.349925 in the getrawmonotonic() due to the negative value from adding the raw value to tv_nsec. A simple solution is to accumulate into a u64, and then normalize it to a timespec_t. Signed-off-by: Jason Wessel [ Reworked variable names and simplified some of the code. - John ] Signed-off-by: John Stultz Cc: Thomas Gleixner Cc: H. Peter Anvin Signed-off-by: Linus Torvalds

timekeeping: Make xtime and wall_to_monotonic static

2010-07-27T10:40:55Z

This patch makes xtime and wall_to_monotonic static, as planned in Documentation/feature-removal-schedule.txt. This will allow for further cleanups to the timekeeping core. Signed-off-by: John Stultz LKML-Reference: <1279068988-21864-10-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner

hrtimer: Cleanup direct access to wall_to_monotonic

2010-07-27T10:40:55Z

Provides an accessor function to replace hrtimer.c's direct access of wall_to_monotonic. This will allow wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz LKML-Reference: <1279068988-21864-9-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner

timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset

2010-07-27T10:40:54Z

update_vsyscall() did not provide the wall_to_monotoinc offset, so arch specific implementations tend to reference wall_to_monotonic directly. This limits future cleanups in the timekeeping core, so this patch fixes the update_vsyscall interface to provide wall_to_monotonic, allowing wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz Cc: Martin Schwidefsky Cc: Anton Blanchard Cc: Paul Mackerras Cc: Tony Luck LKML-Reference: <1279068988-21864-7-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner

time: Kill off CONFIG_GENERIC_TIME

2010-07-27T10:40:54Z

Now that all arches have been converted over to use generic time via clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME config option and simplify the generic code. Signed-off-by: John Stultz LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner