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* hrtimer: move timer stats helper functions to hrtimer.cHeiko Carstens2009-12-10
| | | | | | | | | | | | 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>
* hrtimer: Tune hrtimer_interrupt hang logicThomas Gleixner2009-12-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* hrtimer: Fix /proc/timer_list regressionFeng Tang2009-11-20
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'linus' into timers/coreThomas Gleixner2009-08-14
|\ | | | | | | | | | | | | Reason: Martin's timekeeping cleanup series depends on both timers/core and mainline changes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * timer stats: fix quick check optimizationHeiko Carstens2009-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | hrtimer: Remove cb_entry from struct hrtimerPeter Zijlstra2009-07-22
|/ | | | | | | | 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>
* timer stats: Optimize by adding quick check to avoid function callsHeiko Carstens2009-06-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* timers: Framework for identifying pinned timersArun R Bharadwaj2009-05-13
| | | | | | | | | | | | | | | | | | | | | | | | * 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>
* hrtimer: fix rq->lock inversion (again)Peter Zijlstra2009-03-31
| | | | | | | | | | | | | | | | | | | | 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>
* hrtimer: removing all ur callback modesPeter Zijlstra2008-11-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* hrtimer: clean up unused callback modesPeter Zijlstra2008-11-12
| | | | | | | | | | 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>
* Fix accidental implicit cast in HR-timer conversionDavid Howells2008-11-06
| | | | | | | | | | | | | | 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>
* Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2Thomas Gleixner2008-10-22
|\ | | | | | | | | | | | | | | Conflicts: kernel/time/tick-sched.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * hrtimers: add missing docbook comments to struct hrtimerThomas Gleixner2008-10-20
| | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * Merge commit 'linus/master' into merge-linusArjan van de Ven2008-10-17
| |\ | | | | | | | | | | | | | | | Conflicts: arch/x86/kvm/i8254.c
| * | DECLARE_PER_CPU needs linux/percpu.hStephen Rothwell2008-10-15
| | | | | | | | | | | | Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
| * | rangetimer: fix x86 build failure for the !HRTIMERS caseArjan van de Ven2008-10-07
| | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | hrtimer: peek at the timer queue just before going idleArjan van de Ven2008-09-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | hrtimer: incorporate feedback from Peter ZijlstraArjan van de Ven2008-09-07
| | | | | | | | | | | | | | | | | | | | | | | | (based on lkml review) * use rt_task() * task_nice() has a sign Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
| * | hrtimer: add a hrtimer_start_range() functionArjan van de Ven2008-09-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | hrtimer: another build fixArjan van de Ven2008-09-06
| | | | | | | | | | | | | | | | | | More randconfig testing Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
| * | hrtimer: fix build bug found by IngoArjan van de Ven2008-09-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | hrtimer: turn hrtimers into range timersArjan van de Ven2008-09-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | hrtimer: rename the "expires" struct member to avoid accidental usageArjan van de Ven2008-09-06
| | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | hrtimer: add abstraction functions for accessing the "expires" memberArjan van de Ven2008-09-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | select: Introduce a hrtimeout functionArjan van de Ven2008-09-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a schedule_hrtimeout() function, to be used by select() and poll() in a later patch. This function works similar to schedule_timeout() in most ways, but takes a timespec rather than jiffies. With a lot of contributions/fixes from Thomas Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | |
| \ \
*-. \ \ Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', ↵Thomas Gleixner2008-10-20
|\ \ \ \ | |_|/ / |/| | / | | |/ 'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
| | * hrtimer: prevent migration of per CPU hrtimersThomas Gleixner2008-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * hrtimer: mark migration stateThomas Gleixner2008-09-29
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | 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>
| * hrtimer: reorder struct hrtimer to save 8 bytes on 64bit buildsRichard Kennedy2008-09-24
| | | | | | | | | | | | | | | | | | 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>
| * hrtimer: remove hrtimer_clock_base::reprogram()Mark McLoughlin2008-09-22
| | | | | | | | | | | | | | | | 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>
| * hrtimer: remove hrtimer_clock_base::get_softirq_time()Mark McLoughlin2008-09-22
|/ | | | | | | | | | | | 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>
* hrtimer: remove duplicate helper functionOliver Hartkopp2008-05-03
| | | | | | | | | | | | The helper function hrtimer_callback_running() is used in kernel/hrtimer.c as well as in the updated net/can/bcm.c which now supports hrtimers. Moving the helper function to hrtimer.h removes the duplicate definition in the C-files. Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net> Cc: David Miller <davem@davemloft.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* add hrtimer specific debugobjects codeThomas Gleixner2008-04-30
| | | | | | | | | | | | | | | | | hrtimers have now dynamic users in the network code. Put them under debugobjects surveillance as well. Add calls to the generic object debugging infrastructure and provide fixup functions which allow to keep the system alive when recoverable problems have been detected by the object debugging core code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Greg KH <greg@kroah.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hrtimers: simplify lockdep handlingOleg Nesterov2008-04-17
| | | | | | | | | | | | | | | | In order to avoid the false positive from lockdep, each per-cpu base->lock has the separate lock class and migrate_hrtimers() uses double_spin_lock(). This is overcomplicated: except for migrate_hrtimers() we never take 2 locks at once, and migrate_hrtimers() can use spin_lock_nested(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimer: fix *rmtp handling in hrtimer_nanosleep()Oleg Nesterov2008-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Spotted by Pavel Emelyanov and Alexey Dobriyan. hrtimer_nanosleep() sets restart_block->arg1 = rmtp, but this rmtp points to the local variable which lives in the caller's stack frame. This means that if sys_restart_syscall() actually happens and it is interrupted as well, we don't update the user-space variable, but write into the already dead stack frame. Introduced by commit 04c227140fed77587432667a574b14736a06dd7f hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easier Change the callers to pass "__user *rmtp" to hrtimer_nanosleep(), and change hrtimer_nanosleep() to use copy_to_user() to actually update *rmtp. Small problem remains. man 2 nanosleep states that *rtmp should be written if nanosleep() was interrupted (it says nothing whether it is OK to update *rmtp if nanosleep returns 0), but (with or without this patch) we can dirty *rem even if nanosleep() returns 0. NOTE: this patch doesn't change compat_sys_nanosleep(), because it has other bugs. Fixed by the next patch. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Pavel Emelyanov <xemul@sw.ru> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Toyo Abe <toyoa@mvista.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> include/linux/hrtimer.h | 2 - kernel/hrtimer.c | 51 +++++++++++++++++++++++++----------------------- kernel/posix-timers.c | 14 +------------ 3 files changed, 30 insertions(+), 37 deletions(-)
* time: fix typo in commentsLi Zefan2008-02-08
| | | | | | | | | | | | | | 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>
* Fix compilation of powerpc asm-offsets.c with old gccTony Breeds2008-02-07
| | | | | | | | | | | | | | | | Commit ad7f71674ad7c3c4467e48f6ab9e85516dae2720 ("[POWERPC] Use a sensible default for clock_getres() in the VDSO") corrected the clock resolution reported by the VDSO clock_getres() but introduced another problem in that older versions of gcc (gcc-4.0 and earlier) fail to compile the new code in arch/powerpc/kernel/asm-offsets.c. This fixes it by introducing a new MONOTONIC_RES_NSEC define in the generic code which is equivalent to KTIME_MONOTONIC_RES but is just an integer constant, not a ktime union. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* timerfd: new timerfd APIDavide Libenzi2008-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the new timerfd API as it is implemented by the following patch: int timerfd_create(int clockid, int flags); int timerfd_settime(int ufd, int flags, const struct itimerspec *utmr, struct itimerspec *otmr); int timerfd_gettime(int ufd, struct itimerspec *otmr); The timerfd_create() API creates an un-programmed timerfd fd. The "clockid" parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME. The timerfd_settime() API give new settings by the timerfd fd, by optionally retrieving the previous expiration time (in case the "otmr" parameter is not NULL). The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit is set in the "flags" parameter. Otherwise it's a relative time. The timerfd_gettime() API returns the next expiration time of the timer, or {0, 0} if the timerfd has not been set yet. Like the previous timerfd API implementation, read(2) and poll(2) are supported (with the same interface). Here's a simple test program I used to exercise the new timerfd APIs: http://www.xmailserver.org/timerfd-test2.c [akpm@linux-foundation.org: coding-style cleanups] [akpm@linux-foundation.org: fix ia64 build] [akpm@linux-foundation.org: fix m68k build] [akpm@linux-foundation.org: fix mips build] [akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds] [heiko.carstens@de.ibm.com: fix s390] [akpm@linux-foundation.org: fix powerpc build] [akpm@linux-foundation.org: fix sparc64 more] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* timerfd: introduce a new hrtimer_forward_now() functionDavide Libenzi2008-02-05
| | | | | | | | | | | | I think that advancing the timer against the timer's current "now" can be a pretty common usage, so, w/out exposing hrtimer's internals, we add a new hrtimer_forward_now() function. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* time: delete comments that refer to noexistent symbolsLi Zefan2008-02-03
| | | | | | | | | Function do_timer_interrupt_hook() don't take argument regs, and structure hrtimer_sleeper don't have member cb_pending. So delete comments refering to these symbols. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
* hrtimer: fixup the HRTIMER_CB_IRQSAFE_NO_SOFTIRQ fallbackPeter Zijlstra2008-01-25
| | | | | | | | | | Currently all highres=off timers are run from softirq context, but HRTIMER_CB_IRQSAFE_NO_SOFTIRQ timers expect to run from irq context. Fix this up by splitting it similar to the highres=on case. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: high-res preemption tickPeter Zijlstra2008-01-25
| | | | | | | | | | | | | | | | Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easierAnton Blanchard2007-10-18
| | | | | | | | | | | Pull the copy_to_user out of hrtimer_nanosleep and into the callers (common_nsleep, sys_nanosleep) in preparation for converting compat_sys_nanosleep to use hrtimers. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Add a flag to indicate deferrable timers in /proc/timer_statsVenki Pallipadi2007-07-16
| | | | | | | | | | | | | | | | | | | Add a flag in /proc/timer_stats to indicate deferrable timers. This will let developers/users to differentiate between types of tiemrs in /proc/timer_stats. Deferrable timer and normal timer will appear in /proc/timer_stats as below. 10D, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) 10, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) Also version of timer_stats changes from v0.1 to v0.2 Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 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] high-res timers: resume fixIngo Molnar2007-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | Soeren Sonnenburg reported that upon resume he is getting this backtrace: [<c0119637>] smp_apic_timer_interrupt+0x57/0x90 [<c0142d30>] retrigger_next_event+0x0/0xb0 [<c0104d30>] apic_timer_interrupt+0x28/0x30 [<c0142d30>] retrigger_next_event+0x0/0xb0 [<c0140068>] __kfifo_put+0x8/0x90 [<c0130fe5>] on_each_cpu+0x35/0x60 [<c0143538>] clock_was_set+0x18/0x20 [<c0135cdc>] timekeeping_resume+0x7c/0xa0 [<c02aabe1>] __sysdev_resume+0x11/0x80 [<c02ab0c7>] sysdev_resume+0x47/0x80 [<c02b0b05>] device_power_up+0x5/0x10 it turns out that on resume we mistakenly re-enable interrupts too early. Do the timer retrigger only on the current CPU. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Soeren Sonnenburg <kernel@nn7.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] hrtimers: hrtimer_clock_base description typoAndres Salomon2007-03-06
| | | | | | | | | | | The description for the hrtimer_clock_base struct describes "hrtimer_base". That should be hrtimer_clock_base. Signed-off-by: Andres Salomon <dilinger@debian.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] hrtimers: fix HRTIMER_CB_IRQSAFE_NO_SOFTIRQ descriptionAndres Salomon2007-03-06
| | | | | | | | | | | The description for HRTIMER_CB_IRQSAFE_NO_SOFTIRQ is backwards; "NO SOFTIRQ" sounds a whole lot like it means it must not be run in a softirq. Signed-off-by: Andres Salomon <dilinger@debian.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] kernel-doc fixes for 2.6.20-git15 (non-drivers)Randy Dunlap2007-03-01
| | | | | | | | Fix kernel-doc warnings in 2.6.20-git15 (lib/, mm/, kernel/, include/). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Add SysRq-Q to print timer_list debug infoIngo Molnar2007-02-16
| | | | | | | | | | | Add SysRq-Q to print pending timers and other timer info. 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>