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* Revert "clockevents: Set noop handler in clockevents_exchange_device()"Linus Torvalds2012-01-031-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3b87487ac5008072f138953b07505a7e3493327f upstream. This reverts commit de28f25e8244c7353abed8de0c7792f5f883588c. It results in resume problems for various people. See for example http://thread.gmane.org/gmane.linux.kernel/1233033 http://thread.gmane.org/gmane.linux.kernel/1233389 http://thread.gmane.org/gmane.linux.kernel/1233159 http://thread.gmane.org/gmane.linux.kernel/1227868/focus=1230877 and the fedora and ubuntu bug reports https://bugzilla.redhat.com/show_bug.cgi?id=767248 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/904569 which got bisected down to the stable version of this commit. Reported-by: Jonathan Nieder <jrnieder@gmail.com> Reported-by: Phil Miller <mille121@illinois.edu> Reported-by: Philip Langdale <philipl@overt.org> Reported-by: Tim Gardner <tim.gardner@canonical.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* clockevents: Set noop handler in clockevents_exchange_device()Thomas Gleixner2011-12-091-0/+1
| | | | | | | | | | | | | commit de28f25e8244c7353abed8de0c7792f5f883588c upstream. If a device is shutdown, then there might be a pending interrupt, which will be processed after we reenable interrupts, which causes the original handler to be run. If the old handler is the (broadcast) periodic handler the shutdown state might hang the kernel completely. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* clockevents: Handle empty cpumask gracefullyThomas Gleixner2011-06-031-1/+4
| | | | | | | | | | | | | | | | For UP it's stupid to request an initialized cpumask for the clock event devices. Though we need the mask set even on UP to avoid a horrible ifdeffery especially in the broadcast code. For SMP we can at least try to survive with a warning and set the cpumask of the cpu we're running on. That gives a decent chance to bring the machine up and retrieve the debug info. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Walleij <linus.walleij@linaro.org Cc: Lee Jones <lee.jones@linaro.org> Cc: Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: Stephen Boyd <sboyd@codeaurora.org>
* clockevents/source: Use u64 to make 32bit happyThomas Gleixner2011-05-201-1/+1
| | | | | | unsigned long is not 64bit on 32bit machine. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Provide interface to reconfigure an active clock event deviceThomas Gleixner2011-05-191-0/+20
| | | | | | | | | | | | | | Some ARM SoCs have clock event devices which have their frequency modified due to frequency scaling. Provide an interface which allows to reconfigure an active device. After reconfiguration reprogram the current pending event. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: LAK <linux-arm-kernel@lists.infradead.org> Cc: John Stultz <john.stultz@linaro.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Ingo Molnar <mingo@elte.hu> Link: http://lkml.kernel.org/r/%3C20110518210136.437459958%40linutronix.de%3E
* clockevents: Provide combined configure and register functionThomas Gleixner2011-05-191-0/+44
| | | | | | | | | | | All clockevent devices have the same open coded initialization functions. Provide an interface which does all necessary initialization in the core code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Reviewed-by: Ingo Molnar <mingo@elte.hu> Link: http://lkml.kernel.org/r/%3C20110518210136.331975870%40linutronix.de%3E
* time: Make do_timer() and xtime_lock local to kernel/time/Torben Hohn2011-01-311-1/+0
| | | | | | | | | | | | | | | | All callers of do_timer() are converted to xtime_update(). The only users of xtime_lock are in kernel/time/. Make both local to kernel/time/ and remove them from the global header files. [ tglx: Reuse tick-internal.h instead of creating another local header file. Massaged changelog ] Signed-off-by: Torben Hohn <torbenh@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: johnstul@us.ibm.com Cc: yong.zhang0@gmail.com Cc: hch@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevent: Don't remove broadcast device when cpu is deadXiaotian Feng2010-01-181-1/+2
| | | | | | | | | | | | | | | | | | | | | | Marc reported that the BUG_ON in clockevents_notify() triggers on his system. This happens because the kernel tries to remove an active clock event device (used for broadcasting) from the device list. The handling of devices which can be used as per cpu device and as a global broadcast device is suboptimal. The simplest solution for now (and for stable) is to check whether the device is used as global broadcast device, but this needs to be revisited. [ tglx: restored the cpuweight check and massaged the changelog ] Reported-by: Marc Dionne <marc.c.dionne@gmail.com> Tested-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: Xiaotian Feng <dfeng@redhat.com> LKML-Reference: <1262834564-13033-1-git-send-email-dfeng@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
* Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2009-12-191-3/+15
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timers: Remove duplicate setting of new_base in __mod_timer() clockevents: Prevent clockevent_devices list corruption on cpu hotplug
| * clockevents: Prevent clockevent_devices list corruption on cpu hotplugThomas Gleixner2009-12-111-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Xiaotian Feng triggered a list corruption in the clock events list on CPU hotplug and debugged the root cause. If a CPU registers more than one per cpu clock event device, then only the active clock event device is removed on CPU_DEAD. The unused devices are kept in the clock events device list. On CPU up the clock event devices are registered again, which means that we list_add an already enqueued list_head. That results in list corruption. Resolve this by removing all devices which are associated to the dead CPU on CPU_DEAD. Reported-by: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Xiaotian Feng <dfeng@redhat.com> Cc: stable@kernel.org
* | clockevents: Convert to raw_spinlockThomas Gleixner2009-12-141-7/+7
|/ | | | | | | | | Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
* clockevents: Add missing include to pacify sparseH Hartley Sweeten2009-11-181-0/+2
| | | | | | | | | | | | | | | Include "tick-internal.h" in order to pick up the extern function prototype for clockevents_shutdown(). This quiets the following sparse build noise: warning: symbol 'clockevents_shutdown' was not declared. Should it be static? Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> LKML-Reference: <BD79186B4FD85F4B8E60E381CAEE190901E24550@mi8nycmail19.Mi8.com> Reviewed-by: Yong Zhang <yong.zhang0@gmail.com> Cc: johnstul@us.ibm.com Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* nohz: Allow 32-bit machines to sleep for more than 2.15 secondsJon Hunter2009-11-131-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the dynamic tick code, "max_delta_ns" (member of the "clock_event_device" structure) represents the maximum sleep time that can occur between timer events in nanoseconds. The variable, "max_delta_ns", is defined as an unsigned long which is a 32-bit integer for 32-bit machines and a 64-bit integer for 64-bit machines (if -m64 option is used for gcc). The value of max_delta_ns is set by calling the function "clockevent_delta2ns()" which returns a maximum value of LONG_MAX. For a 32-bit machine LONG_MAX is equal to 0x7fffffff and in nanoseconds this equates to ~2.15 seconds. Hence, the maximum sleep time for a 32-bit machine is ~2.15 seconds, where as for a 64-bit machine it will be many years. This patch changes the type of max_delta_ns to be "u64" instead of "unsigned long" so that this variable is a 64-bit type for both 32-bit and 64-bit machines. It also changes the maximum value returned by clockevent_delta2ns() to KTIME_MAX. Hence this allows a 32-bit machine to sleep for longer than ~2.15 seconds. Please note that this patch also changes "min_delta_ns" to be "u64" too and although this is unnecessary, it makes the patch simpler as it avoids to fixup all callers of clockevent_delta2ns(). [ tglx: changed "unsigned long long" to u64 as we use this data type through out the time code ] Signed-off-by: Jon Hunter <jon-hunter@ti.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1250617512-23567-3-git-send-email-jon-hunter@ti.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevent: Prevent dead lock on clockevents_lockSuresh Siddha2009-08-191-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently clockevents_notify() is called with interrupts enabled at some places and interrupts disabled at some other places. This results in a deadlock in this scenario. cpu A holds clockevents_lock in clockevents_notify() with irqs enabled cpu B waits for clockevents_lock in clockevents_notify() with irqs disabled cpu C doing set_mtrr() which will try to rendezvous of all the cpus. This will result in C and A come to the rendezvous point and waiting for B. B is stuck forever waiting for the spinlock and thus not reaching the rendezvous point. Fix the clockevents code so that clockevents_lock is taken with interrupts disabled and thus avoid the above deadlock. Also call lapic_timer_propagate_broadcast() on the destination cpu so that we avoid calling smp_call_function() in the clockevents notifier chain. This issue left us wondering if we need to change the MTRR rendezvous logic to use stop machine logic (instead of smp_call_function) or add a check in spinlock debug code to see if there are other spinlocks which gets taken under both interrupts enabled/disabled conditions. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com> Cc: "Brown Len" <len.brown@intel.com> LKML-Reference: <1250544899.2709.210.camel@sbs-t61.sc.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimer: Fix migration expiry checkThomas Gleixner2009-07-101-11/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The timer migration expiry check should prevent the migration of a timer to another CPU when the timer expires before the next event is scheduled on the other CPU. Migrating the timer might delay it because we can not reprogram the clock event device on the other CPU. But the code implementing that check has two flaws: - for !HIGHRES the check compares the expiry value with the clock events device expiry value which is wrong for CLOCK_REALTIME based timers. - the check is racy. It holds the hrtimer base lock of the target CPU, but the clock event device expiry value can be modified nevertheless, e.g. by an timer interrupt firing. The !HIGHRES case is easy to fix as we can enqueue the timer on the cpu which was selected by the load balancer. It runs the idle balancing code once per jiffy anyway. So the maximum delay for the timer is the same as when we keep the tick on the current cpu going. In the HIGHRES case we can get the next expiry value from the hrtimer cpu_base of the target CPU and serialize the update with the cpu_base lock. This moves the lock section in hrtimer_interrupt() so we can set next_event to KTIME_MAX while we are handling the expired timers and set it to the next expiry value after we handled the timers under the base lock. While the expired timers are processed timer migration is blocked because the expiry time of the timer is always <= KTIME_MAX. Also remove the now useless clockevents_get_next_event() function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'timers-for-linus-migration' of ↵Linus Torvalds2009-06-151-0/+12
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus-migration' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timers: Logic to move non pinned timers timers: /proc/sys sysctl hook to enable timer migration timers: Identifying the existing pinned timers timers: Framework for identifying pinned timers timers: allow deferrable timers for intervals tv2-tv5 to be deferred Fix up conflicts in kernel/sched.c and kernel/timer.c manually
| * timers: Logic to move non pinned timersArun R Bharadwaj2009-05-131-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]: This patch migrates all non pinned timers and hrtimers to the current idle load balancer, from all the idle CPUs. Timers firing on busy CPUs are not migrated. While migrating hrtimers, care should be taken to check if migrating a hrtimer would result in a latency or not. So we compare the expiry of the hrtimer with the next timer interrupt on the target cpu and migrate the hrtimer only if it expires *after* the next interrupt on the target cpu. So, added a clockevents_get_next_event() helper function to return the next_event on the target cpu's clock_event_device. [ tglx: cleanups and simplifications ] Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | clockevent: export register_device and delta2nsMagnus Damm2009-05-021-0/+2
|/ | | | | | | | | | | | | | | Export the following symbols using EXPORT_SYMBOL_GPL: - clockevent_delta2ns - clockevents_register_device This allows us to build SuperH clockevent and clocksource drivers as modules, see drivers/clocksource/sh_*.c [ Impact: allow modular build of clockevent drivers ] Signed-off-by: Magnus Damm <damm@igel.co.jp> LKML-Reference: <20090501055247.8286.64067.sendpatchset@rx1.opensource.se> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: let set_mode() setup delta informationMagnus Damm2009-01-161-9/+11
| | | | | | | | | | | | | | | | | | | | | | Allow the set_mode() clockevent callback to decide and fill in delta details such as shift, mult, max_delta_ns and min_delta_ns. With this change the clockevent can be registered without delta details which allows us to keep the parent clock disabled until the clockevent gets setup using set_mode(). Letting set_mode() fill in or update delta details allows us to save power by disabling the parent clock while the clockevent is unused. This may however make the parent clock rate change, so next time the clockevent gets enabled we need let set_mode() to update the detla details accordingly. Doing it at registration time is not enough. Furthermore, the delta details seem unused in the case of periodic-only clockevent drivers, so this change also allows registration of such drivers without the delta details filled in. Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* cpumask: convert struct clock_event_device to cpumask pointers.Rusty Russell2008-12-131-0/+2
| | | | | | | | | | | | | Impact: change calling convention of existing clock_event APIs struct clock_event_timer's cpumask field gets changed to take pointer, as does the ->broadcast function. Another single-patch change. For safety, we BUG_ON() in clockevents_register_device() if it's not set. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu>
* clockevents: make device shutdown robustThomas Gleixner2008-09-161-1/+11
| | | | | | | | | | | | | | | | | The device shut down does not cleanup the next_event variable of the clock event device. So when the device is reactivated the possible stale next_event value can prevent the device to be reprogrammed as it claims to wait on a event already. This is the root cause of the resurfacing suspend/resume problem, where systems need key press to come back to life. Fix this by setting next_event to KTIME_MAX when the device is shut down. Use a separate function for shutdown which takes care of that and only keep the direct set mode call in the broadcast code, where we can not touch the next_event value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: prevent clockevent event_handler ending up handler_noopVenkatesh Pallipadi2008-09-051-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a ordering related problem with clockevents code, due to which clockevents_register_device() called after tickless/highres switch will not work. The new clockevent ends up with clockevents_handle_noop as event handler, resulting in no timer activity. The problematic path seems to be * old device already has hrtimer_interrupt as the event_handler * new clockevent device registers with a higher rating * tick_check_new_device() is called * clockevents_exchange_device() gets called * old->event_handler is set to clockevents_handle_noop * tick_setup_device() is called for the new device * which sets new->event_handler using the old->event_handler which is noop. Change the ordering so that new device inherits the proper handler. This does not have any issue in normal case as most likely all the clockevent devices are setup before the highres switch. But, can potentially be affecting some corner case where HPET force detect happens after the highres switch. This was a problem with HPET in MSI mode code that we have been experimenting with. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* time: fix typo in commentsLi Zefan2008-02-081-1/+1
| | | | | | | | | | | | | | Fix typo in comments. BTW: I have to fix coding style in arch/ia64/kernel/time.c also, otherwise checkpatch.pl will be complaining. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> 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: Linus Torvalds <torvalds@linux-foundation.org>
* clockevent: simplify list operationsLi Zefan2008-02-081-7/+4
| | | | | | | | | | | list_for_each_safe() suffices here. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> 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: Linus Torvalds <torvalds@linux-foundation.org>
* x86: make clockevents more robustIngo Molnar2008-01-301-0/+13
| | | | | | | | | detect zero event-device multiplicators - they then cause division-by-zero crashes if a clockevent has been initialized incorrectly. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: warn once when program_event() is called with negative expiryThomas Gleixner2007-12-071-0/+5
| | | | | | | | | | The hrtimer problem with large relative timeouts resulting in a negative expiry time went unnoticed as there is no check in the clockevents_program_event() code. Put a check there with a WARN_ONCE to avoid such problems in the future. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* clockevents: Allow build w/o run-tine usage for migration purposesThomas Gleixner2007-10-121-1/+2
| | | | | | | | | | Migration aid to allow preparatory patches which introduce not yet used parts of clock events code. 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>
* timer: remove clockevents_unregister_notifierMiao Xie2007-08-111-10/+0
| | | | | | | | | | I find a function(clockevents_unregister_notifier) which is not called by anything in tree. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove clockevents_{release,request}_deviceAndi Kleen2007-07-161-41/+0
| | | | | | | | | | | Not called by anything in tree. Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> 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>
* [PATCH] clockevents: remove bad designed sysfs support for nowThomas Gleixner2007-03-261-69/+0
| | | | | | | | | | | | | The current sysfs support of clockevents does not obey the "only one value per file" rule. The real fix is not 2.6.21 material. Therefor remove the sysfs support for now. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] clockevents: add core functionalityThomas Gleixner2007-02-161-0/+345
Architectures register their clock event devices, in the clock events core. Users of the clockevents core can get clock event devices for their use. The clockevents core code provides notification mechanisms for various clock related management events. This allows to control the clock event devices without the architectures having to worry about the details of function assignment. This is also a preliminary for high resolution timers and dynamic ticks to allow the core code to control the clock functionality without intrusive changes to the architecture code. [Fixes-by: Ingo Molnar <mingo@elte.hu>] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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