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2013-03-22hrtimer: Add hrtimer support for CLOCK_TAIJohn Stultz
Add hrtimer support for CLOCK_TAI, as well as posix timer interfaces. Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-07-11timekeeping: Provide hrtimer update functionThomas Gleixner
To finally fix the infamous leap second issue and other race windows caused by functions which change the offsets between the various time bases (CLOCK_MONOTONIC, CLOCK_REALTIME and CLOCK_BOOTTIME) we need a function which atomically gets the current monotonic time and updates the offsets of CLOCK_REALTIME and CLOCK_BOOTTIME with minimalistic overhead. The previous patch which provides ktime_t offsets allows us to make this function almost as cheap as ktime_get() which is going to be replaced in hrtimer_interrupt(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Prarit Bhargava <prarit@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: John Stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/1341960205-56738-7-git-send-email-johnstul@us.ibm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-11hrtimer: Provide clock_was_set_delayed()John Stultz
clock_was_set() cannot be called from hard interrupt context because it calls on_each_cpu(). For fixing the widely reported leap seconds issue it is necessary to call it from hard interrupt context, i.e. the timer tick code, which does the timekeeping updates. Provide a new function which denotes it in the hrtimer cpu base structure of the cpu on which it is called and raise the hrtimer softirq. We then execute the clock_was_set() notificiation from softirq context in run_hrtimer_softirq(). The hrtimer softirq is rarely used, so polling the flag there is not a performance issue. [ tglx: Made it depend on CONFIG_HIGH_RES_TIMERS. We really should get rid of all this ifdeffery ASAP ] Signed-off-by: John Stultz <johnstul@us.ibm.com> Reported-by: Jan Engelhardt <jengelh@inai.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Prarit Bhargava <prarit@redhat.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1341960205-56738-2-git-send-email-johnstul@us.ibm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-06-27Fix some kernel-doc warningsVitaliy Ivanov
Fix 'make htmldocs' warnings: Warning(/include/linux/hrtimer.h:153): No description found for parameter 'clockid' Warning(/include/linux/device.h:604): Excess struct/union/enum/typedef member 'of_match' description in 'device' Warning(/include/net/sock.h:349): Excess struct/union/enum/typedef member 'sk_rmem_alloc' description in 'sock' Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-23hrtimers: Reorder clock basesThomas Gleixner
The ordering of the clock bases is historical due to the CLOCK_REALTIME and CLOCK_MONOTONIC constants. Now the hrtimer bases have their own enumeration due to the gap between CLOCK_MONOTONIC and CLOCK_BOOTTIME. So we can be more clever as most timers end up on the CLOCK_MONOTONIC base due to the virtue of POSIX declaring that relative CLOCK_REALTIME timers are not affected by time changes. In desktop environments this is slowly changing as applications switch to absolute timers, but I've observed empty CLOCK_REALTIME bases often enough. There is no performance penalty or overhead when CLOCK_REALTIME timers are active, but in case they are not we don't skip over a full cache line. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
2011-05-23hrtimers: Avoid touching inactive timer basesThomas Gleixner
Instead of iterating over all possible timer bases avoid it by marking the active bases in the cpu base. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
2011-05-23hrtimers: Make struct hrtimer_cpu_base layout less stupidThomas Gleixner
In the HIGHRES=y case we access the members at the end of struct hrtimer_cpu_base first and then the one at the beginning. Move the hrtimer data to front, so we have linear progressing access. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
2011-05-23timerfd: Manage cancelable timers in timerfdThomas Gleixner
Peter is concerned about the extra scan of CLOCK_REALTIME_COS in the timer interrupt. Yes, I did not think about it, because the solution was so elegant. I didn't like the extra list in timerfd when it was proposed some time ago, but with a rcu based list the list walk it's less horrible than the original global lock, which was held over the list iteration. Requested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
2011-05-02timerfd: Allow timers to be cancelled when clock was setThomas Gleixner
Some applications must be aware of clock realtime being set backward. A simple example is a clock applet which arms a timer for the next minute display. If clock realtime is set backward then the applet displays a stale time for the amount of time which the clock was set backwards. Due to that applications poll the time because we don't have an interface. Extend the timerfd interface by adding a flag which puts the timer onto a different internal realtime clock. All timers on this clock are expired whenever the clock was set. The timerfd core records the monotonic offset when the timer is created. When the timer is armed, then the current offset is compared to the previous recorded offset. When it has changed, then timerfd_settime returns -ECANCELED. When a timer is read the offset is compared and if it changed -ECANCELED returned to user space. Periodic timers are not rearmed in the cancelation case. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <johnstul@us.ibm.com> Cc: Chris Friesen <chris.friesen@genband.com> Tested-by: Kay Sievers <kay.sievers@vrfy.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davide Libenzi <davidel@xmailserver.org> Reviewed-by: Alexander Shishkin <virtuoso@slind.org> Link: http://lkml.kernel.org/r/%3Calpine.LFD.2.02.1104271359580.3323%40ionos%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-05-02hrtimers: Prepare for cancel on clock was set timersThomas Gleixner
Make clock_was_set() unconditional and rename hres_timers_resume to hrtimers_resume. This is a preparatory patch for hrtimers which are cancelled when clock realtime was set. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-10hrtimer: Update hrtimer->state documentationThomas Gleixner
We changed some of the state bits and combinations thereof over time, but never updated the documentation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-21timers: Add CLOCK_BOOTTIME hrtimer baseJohn Stultz
CLOCK_MONOTONIC stops while the system is in suspend. This is because to applications system suspend is invisible. However, there is a growing set of applications that are wanting to be suspend-aware, but do not want to deal with the complications of CLOCK_REALTIME (which might jump around if settimeofday is called). For these applications, I propose a new clockid: CLOCK_BOOTTIME. CLOCK_BOOTTIME is idential to CLOCK_MONOTONIC, except it also includes any time spent in suspend. This patch add hrtimer base for CLOCK_BOOTTIME, using get_monotonic_boottime/ktime_get_boottime, to allow in kernel users to set timers against. CC: Jamie Lokier <jamie@shareable.org> CC: Thomas Gleixner <tglx@linutronix.de> CC: Alexander Shishkin <virtuoso@slind.org> CC: Arve Hjønnevåg <arve@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-02-21time: Introduce get_monotonic_boottime and ktime_get_boottimeJohn Stultz
This adds new functions that return the monotonic time since boot (in other words, CLOCK_MONOTONIC + suspend time). CC: Jamie Lokier <jamie@shareable.org> CC: Thomas Gleixner <tglx@linutronix.de> CC: Alexander Shishkin <virtuoso@slind.org> CC: Arve Hjønnevåg <arve@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-02-21hrtimers: extend hrtimer base code to handle more then 2 clockidsJohn Stultz
The hrtimer code is written mainly with CLOCK_REALTIME and CLOCK_MONOTONIC in mind. These are clockids 0 and 1 resepctively. However, if we are to introduce any new hrtimer bases, using new clockids, we have to skip the cputimers (clockids 2,3) as well as other clockids that may not impelement timers. This patch adds a little bit of indirection between the clockid and the base, so that we can extend the base by one when we add a new clockid at number 7 or so. CC: Jamie Lokier <jamie@shareable.org> CC: Thomas Gleixner <tglx@linutronix.de> CC: Alexander Shishkin <virtuoso@slind.org> CC: Arve Hjønnevåg <arve@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-01-10hrtimer.h: fix kernel-doc warningRandy Dunlap
Fix new kernel-doc notation warning in hrtimer.h: Warning(include/linux/hrtimer.h:150): Excess struct/union/enum/typedef member 'first' description in 'hrtimer_clock_base' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-10hrtimers: Convert hrtimers to use timerlist infrastructureJohn Stultz
Converts the hrtimer code to use the new timerlist infrastructure Signed-off-by: John Stultz <john.stultz@linaro.org> LKML Reference: <1290136329-18291-3-git-send-email-john.stultz@linaro.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> CC: Thomas Gleixner <tglx@linutronix.de> CC: Richard Cochran <richardcochran@gmail.com>
2010-11-10hrtimer: Remove stale comment on curr_timerYong Zhang
curr_timer doesn't resident in struct hrtimer_cpu_base anymore. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> LKML-Reference: <1287892253-2587-1-git-send-email-yong.zhang0@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-04-06hrtimers: Provide schedule_hrtimeout for CLOCK_REALTIMECarsten Emde
The current version of schedule_hrtimeout() always uses the monotonic clock. Some system calls such as mq_timedsend() and mq_timedreceive(), however, require the use of the wall clock due to the definition of the system call. This patch provides the infrastructure to use schedule_hrtimeout() with a CLOCK_REALTIME timer. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Tested-by: Pradyumna Sampath <pradysam@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Veen <arjan@infradead.org> LKML-Reference: <20100402204331.167439615@osadl.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-12-14hrtimers: Convert to raw_spinlocksThomas Gleixner
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>
2009-12-10hrtimer: move timer stats helper functions to hrtimer.cHeiko Carstens
There is no reason to make timer_stats_hrtimer_set_start_info and friends visible to the rest of the kernel. So move all of them to hrtimer.c. Also make timer_stats_hrtimer_set_start_info a static inline function so it gets inlined and we avoid another function call. Based on a patch by Thomas Gleixner. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> LKML-Reference: <20091210095629.GC4144@osiris.boeblingen.de.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-12-10hrtimer: Tune hrtimer_interrupt hang logicThomas Gleixner
The hrtimer_interrupt hang logic adjusts min_delta_ns based on the execution time of the hrtimer callbacks. This is error-prone for virtual machines, where a guest vcpu can be scheduled out during the execution of the callbacks (and the callbacks themselves can do operations that translate to blocking operations in the hypervisor), which in can lead to large min_delta_ns rendering the system unusable. Replace the current heuristics with something more reliable. Allow the interrupt code to try 3 times to catch up with the lost time. If that fails use the total time spent in the interrupt handler to defer the next timer interrupt so the system can catch up with other things which got delayed. Limit that deferment to 100ms. The retry events and the maximum time spent in the interrupt handler are recorded and exposed via /proc/timer_list Inspired by a patch from Marcelo. Reported-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Cc: kvm@vger.kernel.org
2009-11-20hrtimer: Fix /proc/timer_list regressionFeng Tang
commit 507e1231 (timer stats: Optimize by adding quick check to avoid function calls) introduced a regression in /proc/timer_list. /proc/timer_list shows now #0: <c27d46b0>, tick_sched_timer, S:01, <(null)>, /-1 instead of #0: <c27d46b0>, tick_sched_timer, S:01, hrtimer_start, swapper/0 Revert the hrtimer quick check for now. The optimization needs more thought, but this is neither 2.6.32-rc7 nor stable material. [ tglx: - Removed unrelated changes from the original patch - Prevent unneccesary call to timer_stats_update_stats - massaged the changelog ] Signed-off-by: Feng Tang <feng.tang@intel.com> LKML-Reference: <alpine.LFD.2.00.0911181933540.24119@localhost.localdomain> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: stable@kernel.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-14Merge branch 'linus' into timers/coreThomas Gleixner
Reason: Martin's timekeeping cleanup series depends on both timers/core and mainline changes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-07-22hrtimer: Remove cb_entry from struct hrtimerPeter Zijlstra
It's unused, remove it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission>
2009-07-10timer stats: fix quick check optimizationHeiko Carstens
git commit 507e1231 "timer stats: Optimize by adding quick check to avoid function calls" added one wrong check so that one unnecessary function call isn't elimated. time_stats_account_hrtimer() checks if timer->start_pid isn't initialized in order to find out if timer_stats_update_stats() should be called. However start_pid is initialized with -1 instead of 0, so that the function call always happens. Check timer->start_site like in timer_stats_account_timer() to fix this. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-06-24timer stats: Optimize by adding quick check to avoid function callsHeiko Carstens
When the kernel is configured with CONFIG_TIMER_STATS but timer stats are runtime disabled we still get calls to __timer_stats_timer_set_start_info which initializes some fields in the corresponding struct timer_list. So add some quick checks in the the timer stats setup functions to avoid function calls to __timer_stats_timer_set_start_info when timer stats are disabled. In an artificial workload that does nothing but playing ping pong with a single tcp packet via loopback this decreases cpu consumption by 1 - 1.5%. This is part of a modified function trace output on SLES11: perl-2497 [00] 28630647177732388 [+ 125]: sk_reset_timer <-tcp_v4_rcv perl-2497 [00] 28630647177732513 [+ 125]: mod_timer <-sk_reset_timer perl-2497 [00] 28630647177732638 [+ 125]: __timer_stats_timer_set_start_info <-mod_timer perl-2497 [00] 28630647177732763 [+ 125]: __mod_timer <-mod_timer perl-2497 [00] 28630647177732888 [+ 125]: __timer_stats_timer_set_start_info <-__mod_timer perl-2497 [00] 28630647177733013 [+ 93]: lock_timer_base <-__mod_timer Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mustafa Mesanovic <mustafa.mesanovic@de.ibm.com> Cc: Arjan van de Ven <arjan@infradead.org> LKML-Reference: <20090623153811.GA4641@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-13timers: Framework for identifying pinned timersArun R Bharadwaj
* Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]: This patch creates a new framework for identifying cpu-pinned timers and hrtimers. This framework is needed because pinned timers are expected to fire on the same CPU on which they are queued. So it is essential to identify these and not migrate them, in case there are any. For regular timers, the currently existing add_timer_on() can be used queue pinned timers and subsequently mod_timer_pinned() can be used to modify the 'expires' field. For hrtimers, new modes HRTIMER_ABS_PINNED and HRTIMER_REL_PINNED are added to queue cpu-pinned hrtimer. [ tglx: use .._PINNED mode argument instead of creating tons of new functions ] Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-03-31hrtimer: fix rq->lock inversion (again)Peter Zijlstra
It appears I inadvertly introduced rq->lock recursion to the hrtimer_start() path when I delegated running already expired timers to softirq context. This patch fixes it by introducing a __hrtimer_start_range_ns() method that will not use raise_softirq_irqoff() but __raise_softirq_irqoff() which avoids the wakeup. It then also changes schedule() to check for pending softirqs and do the wakeup then, I'm not quite sure I like this last bit, nor am I convinced its really needed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org LKML-Reference: <20090313112301.096138802@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-25hrtimer: removing all ur callback modesPeter Zijlstra
Impact: cleanup, move all hrtimer processing into hardirq context This is an attempt at removing some of the hrtimer complexity by reducing the number of callback modes to 1. This means that all hrtimer callback functions will be ran from HARD-irq context. I went through all the 30 odd hrtimer callback functions in the kernel and saw only one that I'm not quite sure of, which is the one in net/can/bcm.c - hence I'm CC-ing the folks responsible for that code. Furthermore, the hrtimer core now calls callbacks directly with IRQs disabled in case you try to enqueue an expired timer. If this timer is a periodic timer (which should use hrtimer_forward() to advance its time) then it might be possible to end up in an inf. recursive loop due to the fact that hrtimer_forward() doesn't round up to the next timer granularity, and therefore keeps on calling the callback - obviously this needs a fix. Aside from that, this seems to compile and actually boot on my dual core test box - although I'm sure there are some bugs in, me not hitting any makes me certain :-) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12hrtimer: clean up unused callback modesPeter Zijlstra
Impact: cleanup git grep HRTIMER_CB_IRQSAFE revealed half the callback modes are actually unused. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06Fix accidental implicit cast in HR-timer conversionDavid Howells
Fix the hrtimer_add_expires_ns() function. It should take a 'u64 ns' argument, but rather takes an 'unsigned long ns' argument - which might only be 32-bits. On FRV, this results in the kernel locking up because hrtimer_forward() passes the result of a 64-bit multiplication to this function, for which the compiler discards the top 32-bits - something that didn't happen when ktime_add_ns() was called directly. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-22Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2Thomas Gleixner
Conflicts: kernel/time/tick-sched.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-20hrtimers: add missing docbook comments to struct hrtimerThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-20Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', ↵Thomas Gleixner
'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
2008-10-17Merge commit 'linus/master' into merge-linusArjan van de Ven
Conflicts: arch/x86/kvm/i8254.c
2008-10-15DECLARE_PER_CPU needs linux/percpu.hStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2008-10-07rangetimer: fix x86 build failure for the !HRTIMERS caseArjan van de Ven
the timer peek function was on the wrong side of an ifdef, breaking for the !HRTIMERs case. Just provide an empty inline for that case since it doesn't make sense in that scenario. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-29hrtimer: prevent migration of per CPU hrtimersThomas Gleixner
Impact: per CPU hrtimers can be migrated from a dead CPU The hrtimer code has no knowledge about per CPU timers, but we need to prevent the migration of such timers and warn when such a timer is active at migration time. Explicitely mark the timers as per CPU and use a more understandable mode descriptor for the interrupts safe unlocked callback mode, which is used by hrtimer_sleeper and the scheduler code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-29hrtimer: mark migration stateThomas Gleixner
Impact: during migration active hrtimers can be seen as inactive The migration code removes the hrtimers from the queues of the dead CPU and sets the state temporary to INACTIVE. The enqueue code sets it to ACTIVE/PENDING again. Prevent that the wrong state can be seen by using a separate migration state bit. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-24hrtimer: reorder struct hrtimer to save 8 bytes on 64bit buildsRichard Kennedy
reorder struct hrtimer to save 8 bytes on 64 bit builds when CONFIG_TIMER_STATS selected. (also removes 8 bytes from signal_struct) Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-22hrtimer: remove hrtimer_clock_base::reprogram()Mark McLoughlin
hrtimer_clock_base::reprogram() also appears to never have been used, so remove it. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-22hrtimer: remove hrtimer_clock_base::get_softirq_time()Mark McLoughlin
Peter Zijlstra noticed this 8 months ago and I just noticed it again. hrtimer_clock_base::get_softirq_time() is currently unused in the entire tree. In fact, looking at the logs, it appears as if it was never used. Remove it. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-11hrtimer: peek at the timer queue just before going idleArjan van de Ven
As part of going idle, we already look at the time of the next timer event to determine which C-state to select etc. This patch adds functionality that causes the timers that are past their soft expire time, to fire at this time, before we calculate the next wakeup time. This functionality will thus avoid wakeups by running timers before going idle rather than specially waking up for it. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-07hrtimer: incorporate feedback from Peter ZijlstraArjan van de Ven
(based on lkml review) * use rt_task() * task_nice() has a sign Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-07hrtimer: add a hrtimer_start_range() functionArjan van de Ven
this patch adds a _range version of hrtimer_start() so that range timers can be created; the hrtimer_start() function is just a wrapper around this. In addition, hrtimer_start_expires() will now preserve existing ranges. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-06hrtimer: another build fixArjan van de Ven
More randconfig testing Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-06hrtimer: fix build bug found by IngoArjan van de Ven
in some randconfig configurations, hrtimers are used even though the hrtimer config if off; and it broke the build due to some of the new functions being on the wrong side of the ifdef. This patch moves the functions to the other side of the ifdef, fixing the build bug. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-05hrtimer: turn hrtimers into range timersArjan van de Ven
this patch turns hrtimers into range timers; they have 2 expire points 1) the soft expire point 2) the hard expire point the kernel will do it's regular best effort attempt to get the timer run at the hard expire point. However, if some other time fires after the soft expire point, the kernel now has the freedom to fire this timer at this point, and thus grouping the events and preventing a power-expensive wakeup in the future. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-05hrtimer: rename the "expires" struct member to avoid accidental usageArjan van de Ven
To catch code that still touches the "expires" memory directly, rename it to have the compiler complain rather than get nasty, hard to explain, runtime behavior Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-05hrtimer: add abstraction functions for accessing the "expires" memberArjan van de Ven
In order to be able to turn hrtimers into range based, we need to provide accessor functions for getting to the "expires" ktime_t member of the struct hrtimer. This patch adds a set of accessors for this purpose: * hrtimer_set_expires * hrtimer_set_expires_tv64 * hrtimer_add_expires * hrtimer_add_expires_ns * hrtimer_get_expires * hrtimer_get_expires_tv64 * hrtimer_get_expires_ns * hrtimer_expires_remaining * hrtimer_start_expires No users of these new accessors are added yet; these follow in later patches. Hopefully this patch can even go into 2.6.27-rc so that the conversions will not have a bottleneck in -next Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>