linux/kernel/time, branch v2.6.23

Fix timer_stats printout of events/sec

2007-10-07T23:28:43Z

When using /proc/timer_stats on ppc64 I noticed the events/sec field wasnt accurate. Sometimes the integer part was incorrect due to rounding (we werent taking the fractional seconds into consideration). The fraction part is also wrong, we need to pad the printf statement and take the bottom three digits of 1000 times the value. Signed-off-by: Anton Blanchard Acked-by: Ingo Molnar Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

clockevents: remove the suspend/resume workaround^Wthinko

2007-09-23T00:15:34Z

In a desparate attempt to fix the suspend/resume problem on Andrews VAIO I added a workaround which enforced the broadcast of the oneshot timer on resume. This was actually resolving the problem on the VAIO but was just a stupid workaround, which was not tackling the root cause: the assignement of lower idle C-States in the ACPI processor_idle code. The cpuidle patches, which utilize the dynamic tick feature and go faster into deeper C-states exposed the problem again. The correct solution is the previous patch, which prevents lower C-states across the suspend/resume. Remove the enforcement code, including the conditional broadcast timer arming, which helped to pamper over the real problem for quite a time. The oneshot broadcast flag for the cpu, which runs the resume code can never be set at the time when this code is executed. It only gets set, when the CPU is entering a lower idle C-State. Signed-off-by: Thomas Gleixner Tested-by: Andrew Morton Cc: Len Brown Cc: Venkatesh Pallipadi Cc: Rafael J. Wysocki Signed-off-by: Linus Torvalds

clockevents: prevent stale tick update on offline cpu

2007-09-16T13:36:43Z

Taking a cpu offline removes the cpu from the online mask before the CPU_DEAD notification is done. The clock events layer does the cleanup of the dead CPU from the CPU_DEAD notifier chain. tick_do_timer_cpu is used to avoid xtime lock contention by assigning the task of jiffies xtime updates to one CPU. If a CPU is taken offline, then this assignment becomes stale. This went unnoticed because most of the time the offline CPU went dead before the online CPU reached __cpu_die(), where the CPU_DEAD state is checked. In the case that the offline CPU did not reach the DEAD state before we reach __cpu_die(), the code in there goes to sleep for 100ms. Due to the stale time update assignment, the system is stuck forever. Take the assignment away when a cpu is not longer in the cpu_online_mask. We do this in the last call to tick_nohz_stop_sched_tick() when the offline CPU is on the way to the final play_dead() idle entry. Signed-off-by: Thomas Gleixner

clockevents: do not shutdown the oneshot broadcast device

2007-09-16T13:36:43Z

When a cpu goes offline it is removed from the broadcast masks. If the mask becomes empty the code shuts down the broadcast device. This is wrong, because the broadcast device needs to be ready for the online cpu going idle (into a c-state, which stops the local apic timer). Signed-off-by: Thomas Gleixner

clockevents: Enforce oneshot broadcast when broadcast mask is set on resume

2007-09-16T13:36:43Z

The jinxed VAIO refuses to resume without hitting keys on the keyboard when this is not enforced. It is unclear why the cpu ends up in a lower C State without notifying the clock events layer, but enforcing the oneshot broadcast here is safe. Signed-off-by: Thomas Gleixner

timekeeping: Prevent time going backwards on resume

2007-09-16T13:36:43Z

Timekeeping resume adjusts xtime by adding the slept time in seconds and resets the reference value of the clock source (clock->cycle_last). clock->cycle last is used to calculate the delta between the last xtime update and the readout of the clock source in __get_nsec_offset(). xtime plus the offset is the current time. The resume code ignores the delta which had already elapsed between the last xtime update and the actual time of suspend. If the suspend time is short, then we can see time going backwards on resume. Suspend: offs_s = clock->read() - clock->cycle_last; now = xtime + offs_s; timekeeping_suspend_time = read_rtc(); Resume: sleep_time = read_rtc() - timekeeping_suspend_time; xtime.tv_sec += sleep_time; clock->cycle_last = clock->read(); offs_r = clock->read() - clock->cycle_last; now = xtime + offs_r; if sleep_time_seconds == 0 and offs_r < offs_s, then time goes backwards. Fix this by storing the offset from the last xtime update and add it to xtime during resume, when we reset clock->cycle_last: sleep_time = read_rtc() - timekeeping_suspend_time; xtime.tv_sec += sleep_time; xtime += offs_s; /* Fixup xtime offset at suspend time */ clock->cycle_last = clock->read(); offs_r = clock->read() - clock->cycle_last; now = xtime + offs_r; Thanks to Marcelo for tracking this down on the OLPC and providing the necessary details to analyze the root cause. Signed-off-by: Thomas Gleixner Cc: John Stultz Cc: Tosatti

timekeeping: access rtc outside of xtime lock

2007-09-16T13:36:43Z

Lockdep complains about the access of rtc in timekeeping_suspend inside the interrupt disabled region of the write locked xtime lock. Move the access outside. Signed-off-by: Thomas Gleixner Cc: John Stultz

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

2007-09-12T00:21:27Z

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

timer: remove clockevents_unregister_notifier

2007-08-11T22:47:42Z

I find a function(clockevents_unregister_notifier) which is not called by anything in tree. Signed-off-by: Miao Xie Acked-by: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Fix leaks on /proc/{*/sched,sched_debug,timer_list,timer_stats}

2007-07-31T22:39:40Z

On every open/close one struct seq_operations leaks. Kudos to /proc/slab_allocators. Signed-off-by: Alexey Dobriyan Acked-by: Ingo Molnar Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds