12 Nov, 2008
1 commit
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Impact: cleanup
git grep HRTIMER_CB_IRQSAFE revealed half the callback modes are actually
unused.Signed-off-by: Peter Zijlstra
Signed-off-by: Ingo Molnar
11 Nov, 2008
1 commit
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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: [] sched_rt_period_timer+0x9e/0x1fc
{in-hardirq-W} state was registered at:
[] __lock_acquire+0x549/0x121e
[] native_sched_clock+0x88/0x99
[] clocksource_get_next+0x39/0x3f
[] update_wall_time+0x616/0x7df
[] lock_acquire+0x5a/0x74
[] scheduler_tick+0x3a/0x18d
[] _spin_lock+0x1c/0x45
[] scheduler_tick+0x3a/0x18d
[] scheduler_tick+0x3a/0x18d
[] update_process_times+0x3a/0x44
[] tick_periodic+0x63/0x6d
[] tick_handle_periodic+0x14/0x5e
[] timer_interrupt+0x44/0x4a
[] handle_IRQ_event+0x13/0x3d
[] handle_level_irq+0x79/0xbd
[] do_IRQ+0x69/0x7d
[] common_interrupt+0x28/0x30
[] aac_probe_one+0x1a3/0x3f3
[] _spin_unlock_irqrestore+0x36/0x39
[] setup_irq+0x1be/0x1f9
[] start_kernel+0x259/0x2c5
[] 0xffffffff
irq event stamp: 50102
hardirqs last enabled at (50102): [] _spin_unlock_irq+0x20/0x23
hardirqs last disabled at (50101): [] _spin_lock_irq+0xa/0x4b
softirqs last enabled at (50088): [] do_softirq+0x37/0x4d
softirqs last disabled at (50099): [] do_softirq+0x37/0x4dother 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
[] print_usage_bug+0x13e/0x147
[] mark_lock+0x493/0x797
[] __lock_acquire+0x5be/0x121e
[] lock_acquire+0x5a/0x74
[] sched_rt_period_timer+0x9e/0x1fc
[] _spin_lock+0x1c/0x45
[] sched_rt_period_timer+0x9e/0x1fc
[] sched_rt_period_timer+0x9e/0x1fc
[] finish_task_switch+0x41/0xbd
[] native_sched_clock+0x88/0x99
[] sched_rt_period_timer+0x0/0x1fc
[] run_hrtimer_pending+0x54/0xe5
[] sched_rt_period_timer+0x0/0x1fc
[] __do_softirq+0x7b/0xef
[] do_softirq+0x37/0x4d
[] ksoftirqd+0x56/0xc5
[] ksoftirqd+0x0/0xc5
[] kthread+0x38/0x5d
[] kthread+0x0/0x5d
[] kernel_thread_helper+0x7/0x10
=======================Signed-off-by: Gautham R Shenoy
Acked-by: Peter Zijlstra
Acked-by: "Paul E. McKenney"
Signed-off-by: Ingo Molnar
22 Oct, 2008
1 commit
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Conflicts:
kernel/time/tick-sched.c
Signed-off-by: Thomas Gleixner
20 Oct, 2008
3 commits
-
Signed-off-by: Thomas Gleixner
-
hrtimer_start() and hrtimer_start_range_ns() handle relative and
absolute timers.Signed-off-by: Thomas Gleixner
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…tp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
18 Oct, 2008
1 commit
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Conflicts:
arch/x86/kvm/i8254.c
13 Oct, 2008
1 commit
-
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
12 Oct, 2008
1 commit
-
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
29 Sep, 2008
4 commits
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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
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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
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Impact: Stale timers after a CPU went offline.
commit 37bb6cb4097e29ffee970065b74499cbf10603a3
hrtimer: unlock hrtimer_wakeupchanged 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
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Impact: hrtimers which are on the pending list are not migrated at cpu
offline and can be stale foreverAdd the pending list migration when CONFIG_HIGH_RES_TIMERS is enabled
Signed-off-by: Thomas Gleixner
22 Sep, 2008
1 commit
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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
Signed-off-by: Ingo Molnar
11 Sep, 2008
2 commits
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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
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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
08 Sep, 2008
1 commit
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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
06 Sep, 2008
3 commits
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this patch turns hrtimers into range timers; they have 2 expire points
1) the soft expire point
2) the hard expire pointthe 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
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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
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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
Signed-off-by: Thomas Gleixner
21 Aug, 2008
1 commit
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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
Acked-by: Steven Rostedt
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
16 Jul, 2008
2 commits
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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/MakefileSigned-off-by: Ingo Molnar
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* '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
15 Jul, 2008
3 commits
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* '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.
... -
* '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 -
… 'timers/clocksource' and 'timers/posixtimers' into timers/for-linus
10 Jul, 2008
1 commit
-
Conflicts:
arch/arm/mm/Kconfig
04 Jul, 2008
1 commit
-
Due to a possible deadlock, the waking of the softirq was pushed outside
of the hrtimer base locks. See commit 0c96c5979a522c3323c30a078a70120e29b5bdbcUnfortunately 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
Signed-off-by: Linus Torvalds
26 Jun, 2008
1 commit
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It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.Acked-by: Jeremy Fitzhardinge
Reviewed-by: Paul E. McKenney
Signed-off-by: Jens Axboe
27 May, 2008
2 commits
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The variables dns and inc are not used, remove them.
Signed-off-by: Carlos R. Mafra
Cc: tglx@linutronix.de
Signed-off-by: Thomas Gleixner -
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
Cc: xen-devel
Cc: "Rafael J. Wysocki"
Signed-off-by: Thomas Gleixner
25 May, 2008
1 commit
-
As git-grep shows, open_softirq() is always called with the last argument
being NULLblock/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
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
13 May, 2008
1 commit
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Remove the last reminants of dyntick support from the generic kernel.
Signed-off-by: Russell King
04 May, 2008
1 commit
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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
Cc: David Miller
Signed-off-by: Thomas Gleixner
30 Apr, 2008
1 commit
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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
Cc: Greg KH
Cc: Randy Dunlap
Cc: Kay Sievers
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2008
1 commit
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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: [] task_rq_lock+0x56/0xa0but task is already holding lock:
(&cpu_base->lock){++..}, at: [] lock_hrtimer_base+0x31/0x60which 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 raisedTo prevent this we need to move the raise of the softirq out of the
base->lock protected code path.Signed-off-by: Thomas Gleixner
Cc: stable@kernel.org
Acked-by: Peter Zijlstra
28 Apr, 2008
1 commit
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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
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner
21 Apr, 2008
2 commits
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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
-
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
Cc: Peter Zijlstra
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner
17 Apr, 2008
1 commit
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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
Cc: Arjan van de Ven
Cc: Heiko Carstens
Cc: Ingo Molnar
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner