aboutsummaryrefslogtreecommitdiff
path: root/kernel/time/tick-broadcast.c
AgeCommit message (Collapse)Author
2008-01-30timer: clean up tick-broadcast.cThomas Gleixner
clean up tick-broadcast.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-18clockevents: fix reprogramming decision in oneshot broadcastThomas Gleixner
Resolve the following regression of a choppy, almost unusable laptop: http://lkml.org/lkml/2007/12/7/299 http://bugzilla.kernel.org/show_bug.cgi?id=9525 A previous version of the code did the reprogramming of the broadcast device in the return from idle code. This was removed, but the logic in tick_handle_oneshot_broadcast() was kept the same. When a broadcast interrupt happens we signal the expiry to all CPUs which have an expired event. If none of the CPUs has an expired event, which can happen in dyntick mode, then we reprogram the broadcast device. We do not reprogram otherwise, but this is only correct if all CPUs, which are in the idle broadcast state have been woken up. The code ignores, that there might be pending not yet expired events on other CPUs, which are in the idle broadcast state. So the delivery of those events can be delayed for quite a time. Change the tick_handle_oneshot_broadcast() function to check for CPUs, which are in broadcast state and are not woken up by the current event, and enforce the rearming of the broadcast device for those CPUs. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-05time: fix inconsistent function names in commentsLi Zefan
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: 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>
2007-10-17x86: C1E late detection fix. Really switch off lapic timerThomas Gleixner
Doh, I completely missed that devices marked DUMMY are not running the set_mode function. So we force broadcasting, but we keep the local APIC timer running. Let the clock event layer mark the device _after_ switching it off. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-17time: simplify smp_call_function_single() call sequenceAvi Kivity
smp_call_function_single() now knows how to call the function on the current cpu. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-14clockevents: introduce force broadcast notifierThomas Gleixner
The 64bit SMP bootup is slightly different to the 32bit one. It enables the boot CPU local APIC timer before all CPUs are brought up. Some AMD C1E systems have the C1E feature flag only set in the secondary CPU. Due to the early enable of the boot CPU local APIC timer the APIC timer is registered as a fully functional device. When we detect the wreckage during the bringup of the secondary CPU, we need to force the boot CPU into broadcast mode. Add a new notifier reason and implement the force broadcast in the clock events layer. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-12clock events: allow replacement of broadcast timerVenki Pallipadi
Change the broadcast timer, if a timer with higher rating becomes available. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-12clockevents: fix periodic broadcast for oneshot devicesThomas Gleixner
The next_event member of the clock event device is used to keep track of the next periodic event. For one shot only devices it is wrong to clear the variable, as the next event will be based on it. Pointed out by Ralf Baechle Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2007-09-22clockevents: remove the suspend/resume workaround^WthinkoThomas Gleixner
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 <tglx@linutronix.de> Tested-by: Andrew Morton <akpm@linux-foundation.org> Cc: Len Brown <lenb@kernel.org> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-16clockevents: do not shutdown the oneshot broadcast deviceThomas Gleixner
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 <tglx@linutronix.de>
2007-09-16clockevents: Enforce oneshot broadcast when broadcast mask is set on resumeThomas Gleixner
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 <tglx@linutronix.de>
2007-07-21clockevents: fix device replacementThomas Gleixner
When a device is replaced by a better rated device, then the broadcast mode needs to be evaluated again. When the new device has no requirement for broadcasting, then the broadcast bits for the CPU must be cleared. Signed-off-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>
2007-07-21clockevents: fix resume logicThomas Gleixner
We need to make sure, that the clockevent devices are resumed, before the tick is resumed. The current resume logic does not guarantee this. Add CLOCK_EVT_MODE_RESUME and call the set mode functions of the clock event devices before resuming the tick / oneshot functionality. Fixup the existing users. Thanks to Nigel Cunningham for tracking down a long standing thinko, which affected the jinxed VAIO. [akpm@linux-foundation.org: xen build fix] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23Ignore bogus ACPI info for offline CPUsThomas Gleixner
Booting a SMP kernel with maxcpus=1 on a SMP system leads to a hard hang, because ACPI ignores the maxcpus setting and sends timer broadcast info for the offline CPUs. This results in a stuck for ever call to smp_call_function_single() on an offline CPU. Ignore the bogus information and print a kernel error to remind ACPI folks to fix it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-16[PATCH] clockevents: Fix suspend/resume to disk hangsThomas Gleixner
I finally found a dual core box, which survives suspend/resume without crashing in the middle of nowhere. Sigh, I never figured out from the code and the bug reports what's going on. The observed hangs are caused by a stale state transition of the clock event devices, which keeps the RCU synchronization away from completion, when the non boot CPU is brought back up. The suspend/resume in oneshot mode needs the similar care as the periodic mode during suspend to RAM. My assumption that the state transitions during the different shutdown/bringups of s2disk would go through the periodic boot phase and then switch over to highres resp. nohz mode were simply wrong. Add the appropriate suspend / resume handling for the non periodic modes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-06[PATCH] Save/restore periodic tick information over suspend/resumeThomas Gleixner
The programming of periodic tick devices needs to be saved/restored across suspend/resume - otherwise we might end up with a system coming up that relies on getting a PIT (or HPET) interrupt, while those devices default to 'no interrupts' after powerup. (To confuse things it worked to a certain degree on some systems because the lapic gets initialized as a side-effect of SMP bootup.) This suspend / resume thing was dropped unintentionally during the last-minute -mm code reshuffling. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16[PATCH] Add debugging feature /proc/timer_listIngo Molnar
add /proc/timer_list, which prints all currently pending (high-res) timers, all clock-event sources and their parameters in a human-readable form. Sample output: Timer List Version: v0.1 HRTIMER_MAX_CLOCK_BASES: 2 now at 4246046273872 nsecs cpu: 0 clock 0: .index: 0 .resolution: 1 nsecs .get_time: ktime_get_real .offset: 1273998312645738432 nsecs active timers: clock 1: .index: 1 .resolution: 1 nsecs .get_time: ktime_get .offset: 0 nsecs active timers: #0: <f5a90ec8>, hrtimer_sched_tick, hrtimer_stop_sched_tick, swapper/0 # expires at 4246432689566 nsecs [in 386415694 nsecs] #1: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, pcscd/2050 # expires at 4247018194689 nsecs [in 971920817 nsecs] #2: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, irqbalance/1909 # expires at 4247351358392 nsecs [in 1305084520 nsecs] #3: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, crond/2157 # expires at 4249097614968 nsecs [in 3051341096 nsecs] #4: <f5a90ec8>, it_real_fn, do_setitimer, syslogd/1888 # expires at 4251329900926 nsecs [in 5283627054 nsecs] .expires_next : 4246432689566 nsecs .hres_active : 1 .check_clocks : 0 .nr_events : 31306 .idle_tick : 4246020791890 nsecs .tick_stopped : 1 .idle_jiffies : 986504 .idle_calls : 40700 .idle_sleeps : 36014 .idle_entrytime : 4246019418883 nsecs .idle_sleeptime : 4178181972709 nsecs cpu: 1 clock 0: .index: 0 .resolution: 1 nsecs .get_time: ktime_get_real .offset: 1273998312645738432 nsecs active timers: clock 1: .index: 1 .resolution: 1 nsecs .get_time: ktime_get .offset: 0 nsecs active timers: #0: <f5a90ec8>, hrtimer_sched_tick, hrtimer_restart_sched_tick, swapper/0 # expires at 4246050084568 nsecs [in 3810696 nsecs] #1: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, atd/2227 # expires at 4261010635003 nsecs [in 14964361131 nsecs] #2: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, smartd/2332 # expires at 5469485798970 nsecs [in 1223439525098 nsecs] .expires_next : 4246050084568 nsecs .hres_active : 1 .check_clocks : 0 .nr_events : 24043 .idle_tick : 4246046084568 nsecs .tick_stopped : 0 .idle_jiffies : 986510 .idle_calls : 26360 .idle_sleeps : 22551 .idle_entrytime : 4246043874339 nsecs .idle_sleeptime : 4170763761184 nsecs tick_broadcast_mask: 00000003 event_broadcast_mask: 00000001 CPU#0's local event device: Clock Event Device: lapic capabilities: 0000000e max_delta_ns: 807385544 min_delta_ns: 1443 mult: 44624025 shift: 32 set_next_event: lapic_next_event set_mode: lapic_timer_setup event_handler: hrtimer_interrupt .installed: 1 .expires: 4246432689566 nsecs CPU#1's local event device: Clock Event Device: lapic capabilities: 0000000e max_delta_ns: 807385544 min_delta_ns: 1443 mult: 44624025 shift: 32 set_next_event: lapic_next_event set_mode: lapic_timer_setup event_handler: hrtimer_interrupt .installed: 1 .expires: 4246050084568 nsecs Clock Event Device: hpet capabilities: 00000007 max_delta_ns: 2147483647 min_delta_ns: 3352 mult: 61496110 shift: 32 set_next_event: hpet_next_event set_mode: hpet_set_mode event_handler: handle_nextevt_broadcast Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> 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>
2007-02-16[PATCH] tick-management: dyntick / highres functionalityThomas Gleixner
With Ingo Molnar <mingo@elte.hu> Add functions to provide dynamic ticks and high resolution timers. The code which keeps track of jiffies and handles the long idle periods is shared between tick based and high resolution timer based dynticks. The dyntick functionality can be disabled on the kernel commandline. Provide also the infrastructure to support high resolution timers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: 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>
2007-02-16[PATCH] tick-management: broadcast functionalityThomas Gleixner
With Ingo Molnar <mingo@elte.hu> Add broadcast functionality, so per cpu clock event devices can be registered as dummy devices or switched from/to broadcast on demand. The broadcast function distributes the events via the broadcast function of the clock event device. This is primarily designed to replace the switch apic timer to / from IPI in power states, where the apic stops. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: 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>