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* hrtimer: clean up unused callback modesPeter Zijlstra2008-11-121-9/+0
| | | | | | | | | | 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>
* timers: handle HRTIMER_CB_IRQSAFE_UNLOCKED correctly from softirq contextGautham R Shenoy2008-11-111-1/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix incorrect locking triggered during hotplug-intense stress-tests While migrating the the CB_IRQSAFE_UNLOCKED timers during a cpu-offline, we queue them on the cb_pending list, so that they won't go stale. Thus, when the callbacks of the timers run from the softirq context, they could run into potential deadlocks, since these callbacks assume that they're running with irq's disabled, thereby annoying lockdep! Fix this by emulating hardirq context while running these callbacks from the hrtimer softirq. ================================= [ INFO: inconsistent lock state ] 2.6.27 #2 -------------------------------- inconsistent {in-hardirq-W} -> {hardirq-on-W} usage. ksoftirqd/0/4 [HC0[0]:SC1[1]:HE1:SE0] takes: (&rq->lock){++..}, at: [<c011db84>] sched_rt_period_timer+0x9e/0x1fc {in-hardirq-W} state was registered at: [<c014103c>] __lock_acquire+0x549/0x121e [<c0107890>] native_sched_clock+0x88/0x99 [<c013aa12>] clocksource_get_next+0x39/0x3f [<c0139abc>] update_wall_time+0x616/0x7df [<c0141d6b>] lock_acquire+0x5a/0x74 [<c0121724>] scheduler_tick+0x3a/0x18d [<c047ed45>] _spin_lock+0x1c/0x45 [<c0121724>] scheduler_tick+0x3a/0x18d [<c0121724>] scheduler_tick+0x3a/0x18d [<c012c436>] update_process_times+0x3a/0x44 [<c013c044>] tick_periodic+0x63/0x6d [<c013c062>] tick_handle_periodic+0x14/0x5e [<c010568c>] timer_interrupt+0x44/0x4a [<c0150c9f>] handle_IRQ_event+0x13/0x3d [<c0151c14>] handle_level_irq+0x79/0xbd [<c0105634>] do_IRQ+0x69/0x7d [<c01041e4>] common_interrupt+0x28/0x30 [<c047007b>] aac_probe_one+0x1a3/0x3f3 [<c047ec2d>] _spin_unlock_irqrestore+0x36/0x39 [<c01512b4>] setup_irq+0x1be/0x1f9 [<c065d70b>] start_kernel+0x259/0x2c5 [<ffffffff>] 0xffffffff irq event stamp: 50102 hardirqs last enabled at (50102): [<c047ebf4>] _spin_unlock_irq+0x20/0x23 hardirqs last disabled at (50101): [<c047edc2>] _spin_lock_irq+0xa/0x4b softirqs last enabled at (50088): [<c0128ba6>] do_softirq+0x37/0x4d softirqs last disabled at (50099): [<c0128ba6>] do_softirq+0x37/0x4d other info that might help us debug this: no locks held by ksoftirqd/0/4. stack backtrace: Pid: 4, comm: ksoftirqd/0 Not tainted 2.6.27 #2 [<c013f6cb>] print_usage_bug+0x13e/0x147 [<c013fef5>] mark_lock+0x493/0x797 [<c01410b1>] __lock_acquire+0x5be/0x121e [<c0141d6b>] lock_acquire+0x5a/0x74 [<c011db84>] sched_rt_period_timer+0x9e/0x1fc [<c047ed45>] _spin_lock+0x1c/0x45 [<c011db84>] sched_rt_period_timer+0x9e/0x1fc [<c011db84>] sched_rt_period_timer+0x9e/0x1fc [<c01210fd>] finish_task_switch+0x41/0xbd [<c0107890>] native_sched_clock+0x88/0x99 [<c011dae6>] sched_rt_period_timer+0x0/0x1fc [<c0136dda>] run_hrtimer_pending+0x54/0xe5 [<c011dae6>] sched_rt_period_timer+0x0/0x1fc [<c0128afb>] __do_softirq+0x7b/0xef [<c0128ba6>] do_softirq+0x37/0x4d [<c0128c12>] ksoftirqd+0x56/0xc5 [<c0128bbc>] ksoftirqd+0x0/0xc5 [<c0134649>] kthread+0x38/0x5d [<c0134611>] kthread+0x0/0x5d [<c0104477>] kernel_thread_helper+0x7/0x10 ======================= Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2Thomas Gleixner2008-10-221-21/+185
|\ | | | | | | | | | | | | | | Conflicts: kernel/time/tick-sched.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * hrtimers: simplify hrtimer_peek_ahead_timers()Thomas Gleixner2008-10-201-9/+3
| | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * hrtimers: fix docbook commentsThomas Gleixner2008-10-201-2/+2
| | | | | | | | | | | | | | hrtimer_start() and hrtimer_start_range_ns() handle relative and absolute timers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * Merge commit 'linus/master' into merge-linusArjan van de Ven2008-10-171-10/+85
| |\ | | | | | | | | | | | | | | | Conflicts: arch/x86/kvm/i8254.c
| * | rangetimers: fix the bug reported by Ingo for realArjan van de Ven2008-10-131-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | and please hand me a brown paper bag (thanks to Thomas for pointing out this very obvious bug) Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
| * | rangetimer: fix BUG_ON reported by IngoArjan van de Ven2008-10-111-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | There's a small race/chance that, while hrtimers are enabled globally, they're later not enabled when we're calling the hrtimer_interrupt() function, which then BUG_ON()'s for that. This patch closes that race/gap. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
| * | hrtimer: peek at the timer queue just before going idleArjan van de Ven2008-09-111-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: make the nanosleep() syscall use the per process slackArjan van de Ven2008-09-111-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | This patch makes the nanosleep() system call use the per process slack value; with this users are able to externally control existing applications to reduce the wakeup rate. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
| * | hrtimer: add a hrtimer_start_range() functionArjan van de Ven2008-09-071-3/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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: turn hrtimers into range timersArjan van de Ven2008-09-061-4/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: convert kernel/* to the new hrtimer apisArjan van de Ven2008-09-061-21/+23
| | | | | | | | | | | | | | | | | | | | | | | | In order to be able to do range hrtimers we need to use accessor functions to the "expire" member of the hrtimer struct. This patch converts kernel/* to these accessors. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
| * | select: Introduce a hrtimeout functionArjan van de Ven2008-09-061-0/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
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*-. \ \ Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', ↵Thomas Gleixner2008-10-201-18/+92
|\ \ \ \ | |_|/ / |/| | / | | |/ 'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
| | * hrtimer: prevent migration of per CPU hrtimersThomas Gleixner2008-09-291-12/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Gleixner2008-09-291-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: fix migration of CB_IRQSAFE_NO_SOFTIRQ hrtimersThomas Gleixner2008-09-291-3/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Stale timers after a CPU went offline. commit 37bb6cb4097e29ffee970065b74499cbf10603a3 hrtimer: unlock hrtimer_wakeup changed the hrtimer sleeper callback mode to CB_IRQSAFE_NO_SOFTIRQ due to locking problems. A result of this change is that when enqueue is called for an already expired hrtimer the callback function is not longer called directly from the enqueue code. The normal callers have been fixed in the code, but the migration code which moves hrtimers from a dead CPU to a live CPU was not made aware of this. This can be fixed by checking the timer state after the call to enqueue in the migration code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * hrtimer: migrate pending list on cpu offlineThomas Gleixner2008-09-291-1/+33
| |/ |/| | | | | | | | | | | | | | | Impact: hrtimers which are on the pending list are not migrated at cpu offline and can be stale forever Add the pending list migration when CONFIG_HIGH_RES_TIMERS is enabled Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * hrtimer: remove hrtimer_clock_base::get_softirq_time()Mark McLoughlin2008-09-221-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | 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>
| * migrate_timers: add comment, use spinlock_irq()Oleg Nesterov2008-08-211-5/+6
|/ | | | | | | | | | | | | Add the comment to explain why the double lock in migrate_timers() can't deadlock. Change the code to use spinlock_irq() instead of local_irq_disable() + spin_lock(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar2008-07-151-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * on_each_cpu(): kill unused 'retry' parameterJens Axboe2008-06-261-1/+1
| | | | | | | | | | | | | | | | | | It's not even passed on to smp_call_function() anymore, since that was removed. So kill it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | Merge branch 'timers/for-linus' of ↵Linus Torvalds2008-07-151-5/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: add PCI ID for 6300ESB force hpet x86: add another PCI ID for ICH6 force-hpet kernel-paramaters: document pmtmr= command line option acpi_pm clccksource: fix printk format warning nohz: don't stop idle tick if softirqs are pending. pmtmr: allow command line override of ioport nohz: reduce jiffies polling overhead hrtimer: Remove unused variables in ktime_divns() hrtimer: remove warning in hres_timers_resume posix-timers: print RT watchdog message
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| *-. | Merge commit '900cfa46191a7d87cf1891924cb90499287fd235'; branches ↵Thomas Gleixner2008-07-141-5/+2
| |\ \| | | | | | | | | | | | | 'timers/nohz', 'timers/clocksource' and 'timers/posixtimers' into timers/for-linus
| | * | hrtimer: Remove unused variables in ktime_divns()Carlos R. Mafra2008-05-261-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The variables dns and inc are not used, remove them. Signed-off-by: Carlos R. Mafra <crmafra@gmail.com> Cc: tglx@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * | hrtimer: remove warning in hres_timers_resumeJeremy Fitzhardinge2008-05-261-2/+0
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hres_timers_resume() warns if there appears to be more than one cpu online. This warning makes sense when the suspend/resume mechanism offlines all cpus but one during the suspend/resume process. However, Xen suspend does not need to offline the other cpus; it merely keeps them tied up in stop_machine() while the virtual machine is suspended. The warning hres_timers_resume issues is therefore spurious. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: xen-devel <xen-devel@lists.xensource.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds2008-07-151-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (241 commits) [ARM] 5171/1: ep93xx: fix compilation of modules using clocks [ARM] 5133/2: at91sam9g20 defconfig file [ARM] 5130/4: Support for the at91sam9g20 [ARM] 5160/1: IOP3XX: gpio/gpiolib support [ARM] at91: Fix NAND FLASH timings for at91sam9x evaluation kits. [ARM] 5084/1: zylonite: Register AC97 device [ARM] 5085/2: PXA: Move AC97 over to the new central device declaration model [ARM] 5120/1: pxa: correct platform driver names for PXA25x and PXA27x UDC drivers [ARM] 5147/1: pxaficp_ir: drop pxa_gpio_mode calls, as pin setting [ARM] 5145/1: PXA2xx: provide api to control IrDA pins state [ARM] 5144/1: pxaficp_ir: cleanup includes [ARM] pxa: remove pxa_set_cken() [ARM] pxa: allow clk aliases [ARM] Feroceon: don't disable BPU on boot [ARM] Orion: LED support for HP mv2120 [ARM] Orion: add RD88F5181L-FXO support [ARM] Orion: add RD88F5181L-GE support [ARM] Orion: add Netgear WNR854T support [ARM] s3c2410_defconfig: update for current build [ARM] Acer n30: Minor style and indentation fixes. ...
| * | | Merge branch 'imx' into develRussell King2008-07-101-0/+8
| |\| | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/arm/mm/Kconfig
| * | | dyntick: Remove last reminants of dyntick supportRussell King2008-05-121-1/+1
| | |/ | |/| | | | | | | | | | | | | Remove the last reminants of dyntick support from the generic kernel. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | | Merge branch 'core/softirq' of ↵Linus Torvalds2008-07-151-1/+1
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core/softirq' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: softirq: remove irqs_disabled warning from local_bh_enable softirq: remove initialization of static per-cpu variable Remove argument from open_softirq which is always NULL
| * | Remove argument from open_softirq which is always NULLCarlos R. Mafra2008-05-251-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As git-grep shows, open_softirq() is always called with the last argument being NULL block/blk-core.c: open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); kernel/hrtimer.c: open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL); kernel/rcuclassic.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); kernel/rcupreempt.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); kernel/sched.c: open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL); kernel/softirq.c: open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL); kernel/softirq.c: open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL); kernel/timer.c: open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); net/core/dev.c: open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL); net/core/dev.c: open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL); This observation has already been made by Matthew Wilcox in June 2002 (http://www.cs.helsinki.fi/linux/linux-kernel/2002-25/0687.html) "I notice that none of the current softirq routines use the data element passed to them." and the situation hasn't changed since them. So it appears we can safely remove that extra argument to save 128 (54) bytes of kernel data (text). Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* / hrtimer: prevent migration for raising softirqSteven Rostedt2008-07-031-0/+8
|/ | | | | | | | | | | | | | | | Due to a possible deadlock, the waking of the softirq was pushed outside of the hrtimer base locks. See commit 0c96c5979a522c3323c30a078a70120e29b5bdbc Unfortunately this allows the task to migrate after setting up the softirq and raising it. Since softirqs run a queue that is per-cpu we may raise the softirq on the wrong CPU and this will keep the queued softirq task from running. To solve this issue, this patch disables preemption around the releasing of the hrtimer lock and raising of the softirq. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hrtimer: remove duplicate helper functionOliver Hartkopp2008-05-031-9/+0
| | | | | | | | | | | | 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 Gleixner2008-04-301-20/+157
| | | | | | | | | | | | | | | | | 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>
* hrtimer: raise softirq unlocked to avoid circular lock dependencyThomas Gleixner2008-04-281-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The scheduler hrtimer bits in 2.6.25 introduced a circular lock dependency in a rare code path: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.25-sched-devel.git-x86-latest.git #19 ------------------------------------------------------- X/2980 is trying to acquire lock: (&rq->rq_lock_key#2){++..}, at: [<ffffffff80230146>] task_rq_lock+0x56/0xa0 but task is already holding lock: (&cpu_base->lock){++..}, at: [<ffffffff80257ae1>] lock_hrtimer_base+0x31/0x60 which lock already depends on the new lock. The scenario which leads to this is: posix-timer signal is delivered -> posix-timer is rearmed timer is already expired in hrtimer_enqueue() -> softirq is raised To prevent this we need to move the raise of the softirq out of the base->lock protected code path. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
* hrtimer: timeout too long when using HRTIMER_CB_SOFTIRQBodo Stroesser2008-04-271-2/+13
| | | | | | | | | | | | | | | | | | | | When using hrtimer with timer->cb_mode == HRTIMER_CB_SOFTIRQ in some cases the clockevent is not programmed. This happens, if: - a timer is rearmed while it's state is HRTIMER_STATE_CALLBACK - hrtimer_reprogram() returns -ETIME, when it is called after CALLBACK is finished. This occurs if the new timer->expires is in the past when CALLBACK is done. In this case, the timer needs to be removed from the tree and put onto the pending list again. The patch is against 2.6.22.5, but AFAICS, it is relevant for 2.6.25 also (in run_hrtimer_pending()). Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com> Cc: stable@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimer: optimize the softirq time optimizationThomas Gleixner2008-04-211-4/+3
| | | | | | | | | | | | The previous optimization did not take the case into account where a clock provides its own softirq_get_time() function. Check for the availablitiy of the clock get time function first and then check if we need to retrieve the time for both clocks via hrtimer_softirq_gettime() to avoid a double evaluation of time in that case as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimer: reduce calls to hrtimer_get_softirq_time()Dimitri Sivanich2008-04-211-32/+32
| | | | | | | | | | | | | | | | | | | | It seems that hrtimer_run_queues() is calling hrtimer_get_softirq_time() more often than it needs to. This can cause frequent contention on systems with large numbers of processors/cores. With this patch, hrtimer_run_queues only calls hrtimer_get_softirq_time() if there is a pending timer in one of the hrtimer bases, and only once. This also combines hrtimer_run_queues() and the inline run_hrtimer_queue() into one function. [ tglx@linutronix.de: coding style ] Signed-off-by: Dimitri Sivanich <sivanich@sgi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimers: simplify lockdep handlingOleg Nesterov2008-04-171-5/+4
| | | | | | | | | | | | | | | | 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: use nanosleep specific restart_block fieldsThomas Gleixner2008-04-171-7/+6
| | | | | | | Convert all the nanosleep related users of restart_block to the new nanosleep specific restart_block fields. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimer: catch expired CLOCK_REALTIME timers earlyThomas Gleixner2008-02-141-0/+11
| | | | | | | | | | | | | | | A CLOCK_REALTIME timer, which has an absolute expiry time less than the clock realtime offset calls with a negative delta into the clock events code and triggers the WARN_ON() there. This is a false positive and needs to be prevented. Check the result of timer->expires - timer->base->offset right away and return -ETIME right away. Thanks to Frans Pop, who reported the problem and tested the fixes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Frans Pop <elendil@planet.nl>
* hrtimer: check relative timeouts for overflowThomas Gleixner2008-02-141-17/+20
| | | | | | | | | | | | | | | | | Various user space callers ask for relative timeouts. While we fixed that overflow issue in hrtimer_start(), the sites which convert relative user space values to absolute timeouts themself were uncovered. Instead of putting overflow checks into each place add a function which does the sanity checking and convert all affected callers to use it. Thanks to Frans Pop, who reported the problem and tested the fixes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Tested-by: Frans Pop <elendil@planet.nl>
* hrtimer: don't modify restart_block->fn in restart functionsOleg Nesterov2008-02-101-4/+0
| | | | | | | | | | | | | | | | hrtimer_nanosleep_restart() clears/restores restart_block->fn. This is pointless and complicates its usage. Note that if sys_restart_syscall() doesn't actually happen, we have a bogus "pending" restart->fn anyway, this is harmless. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Alexey Dobriyan <adobriyan@sw.ru> 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>
* hrtimer: fix *rmtp handling in hrtimer_nanosleep()Oleg Nesterov2008-02-101-24/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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(-)
* timerfd: new timerfd APIDavide Libenzi2008-02-051-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* hrtimer: fix hrtimer_init_sleeper() usersPeter Zijlstra2008-02-011-0/+2
| | | | | | | | | | | | | | | | | | this patch: commit 37bb6cb4097e29ffee970065b74499cbf10603a3 Author: Peter Zijlstra <a.p.zijlstra@chello.nl> Date: Fri Jan 25 21:08:32 2008 +0100 hrtimer: unlock hrtimer_wakeup Broke hrtimer_init_sleeper() users. It forgot to fix up the futex caller of this function to detect the failed queueing and messed up the do_nanosleep() caller in that it could leak a TASK_INTERRUPTIBLE state. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* hrtimer: unlock hrtimer_wakeupPeter Zijlstra2008-01-251-1/+3
| | | | | | | | | | | | | | | | hrtimer_wakeup creates a base->lock rq->lock lock dependancy. Avoid this by switching to HRTIMER_CB_IRQSAFE_NO_SOFTIRQ which doesn't hold base->lock. This fully untangles hrtimer locks from the scheduler locks, and allows hrtimer usage in the scheduler proper. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* hrtimer: fixup the HRTIMER_CB_IRQSAFE_NO_SOFTIRQ fallbackPeter Zijlstra2008-01-251-131/+139
| | | | | | | | | | 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>
* hrtimer: clean up cpu->base locking tricksPeter Zijlstra2008-01-251-1/+19
| | | | | | | | In order to more easily allow for the scheduler to use timers, clean up the locking a bit. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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