20 Oct, 2008
1 commit
-
…tp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
18 Oct, 2008
1 commit
-
We have two separate nohz function calls in irq_enter() for no good
reason. Just call a single NOHZ function from irq_enter() and call
the bits in the tick code.Signed-off-by: Thomas Gleixner
17 Oct, 2008
2 commits
-
This is basically a genericization of Jens Axboe's block layer
remote softirq changes.Signed-off-by: David S. Miller
Signed-off-by: Jens Axboe -
This fixes the broken 77af7e3403e7314c47b0c07fbc5e4ef21d939532
("softirq, warning fix: correct a format to avoid a warning") fix
correctly.The type of a pointer subtraction is not "int", nor is it "long". It
can be either (or something else). It's "ptrdiff_t", and the printk
format for it is "%td".Cc: Frederic Weisbecker
Cc: Ingo Molnar
Signed-off-by: Linus Torvalds
03 Oct, 2008
1 commit
-
Last -tip gives this warning:
kernel/softirq.c: Dans la fonction «__do_softirq» :
kernel/softirq.c:216: attention : format «%ld» expects type «long int», but argument 2 has type «int»This patch corrects the format type, and a small mistake in the "softirq" word.
Signed-off-by: Frederic Weisbecker
Signed-off-by: Ingo Molnar
02 Oct, 2008
1 commit
-
if a preempt count leaks out of a softirq handler it can be very hard
to figure it out. Add a debug check for this.Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
07 Sep, 2008
1 commit
-
We don't need whole 32 of them, only NR_SOFTIRQS.
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
27 Jul, 2008
1 commit
-
A previous patch added the early_initcall(), to allow a cleaner hooking of
pre-SMP initcalls. Now we remove the older interface, converting all
existing users to the new one.[akpm@linux-foundation.org: cleanups]
[akpm@linux-foundation.org: build fix]
[kosaki.motohiro@jp.fujitsu.com: warning fix]
[kosaki.motohiro@jp.fujitsu.com: warning fix]
Signed-off-by: Eduard - Gabriel Munteanu
Cc: Tom Zanussi
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Jul, 2008
2 commits
-
Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:scheduler switch to idle task
enable interruptsWindow starts here
----> interrupt happens (does not set NEED_RESCHED)
irq_exit() stops the tick----> interrupt happens (does set NEED_RESCHED)
return from schedule()
cpu_idle(): preempt_disable();
Window ends here
The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.cpu_idle()
{
preempt_disable();while(1) {
tick_nohz_stop_sched_tick(1); ,
Debugged-by: eric miao
Signed-off-by: Thomas Gleixner
16 Jul, 2008
1 commit
-
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
15 Jul, 2008
1 commit
-
* '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
26 Jun, 2008
2 commits
-
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 -
It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.Acked-by: Jeremy Fitzhardinge
Signed-off-by: Jens Axboe
24 Jun, 2008
1 commit
-
Hidehiro Kawai noticed that sched_setscheduler() can fail in
stop_machine: it calls sched_setscheduler() from insmod, which can
have CAP_SYS_MODULE without CAP_SYS_NICE.Two cases could have failed, so are changed to sched_setscheduler_nocheck:
kernel/softirq.c:cpu_callback()
- CPU hotplug callback
kernel/stop_machine.c:__stop_machine_run()
- Called from various places, including modprobe()Signed-off-by: Rusty Russell
Cc: Jeremy Fitzhardinge
Cc: Hidehiro Kawai
Cc: Andrew Morton
Cc: linux-mm@kvack.org
Cc: sugita
Cc: Satoshi OSHIMA
Signed-off-by: Ingo Molnar
20 Jun, 2008
1 commit
-
There's no need to use local_irq_save() over local_irq_disable() in the
local_bh_enable code since it is a bug to call it with irqs disabled and
do_softirq will enable irqs if there is any pending work.Consolidate the code from local_bh_enable and ..._ip to avoid having a
disconnect between them in the warnings they trigger that is currently
there.Also always trigger the warning on in_irq(), not just in the
trace-irqflags case.Signed-off-by: Johannes Berg
Cc: Michael Buesch
Cc: David Ellingsworth
Cc: Linus Torvalds
Signed-off-by: Ingo Molnar
18 Jun, 2008
1 commit
-
Signed-off-by: Vegard Nossum
Signed-off-by: Ingo Molnar
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
01 May, 2008
1 commit
-
currently cpu hotplug (unplug) seems broken on s390 and likely others. On cpu
unplug the system starts to behave very strange and hangs.I bisected the problem to the following commit:
commit 48f20a9a9488c432fc86df1ff4b7f4fa895d1183
Author: Olof Johansson
Date: Tue Mar 4 15:23:25 2008 -0800
tasklets: execute tasklets in the same order they were queuedReverting this patch seems to fix the problem. I looked into takeover_tasklet
and it seems that there is a way to corrupt the tail pointer of the current
cpu. If the tasklet list of the frozen cpu is empty, the tail pointer of the
current cpu points to the address of the head pointer of the stopped cpu and
not to the next pointer of a tasklet_struct.This patch avoids the list splice of the list is empty and cpu hotplug seems
to work as the tail pointer is not corrupted. Olof, can you look into that
patch and ACK/NACK it so Andrew can push this to Linus, if appropriate?
Please note that some lines are longer than 80 chars, but line-wrapping looked
worse that this version.Signed-off-by: Christian Borntraeger
Acked-by: Olof Johansson
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Apr, 2008
1 commit
-
I noticed this when looking at an openswan issue. Openswan (ab?)uses the
tasklet API to defer processing of packets in some situations, with one
packet per tasklet_action(). I started noticing sequences of
backwards-ordered sequence numbers coming over the wire, since new tasklets
are always queued at the head of the list but processed sequentially.Convert it to instead append new entries to the tail of the list. As an
extra bonus, the splicing code in takeover_tasklets() no longer has to
iterate over the list.Signed-off-by: Olof Johansson
Cc: "David S. Miller"
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
01 Mar, 2008
1 commit
-
The PREEMPT-RCU can get stuck if a CPU goes idle and NO_HZ is set. The
idle CPU will not progress the RCU through its grace period and a
synchronize_rcu my get stuck. Without this patch I have a box that will
not boot when PREEMPT_RCU and NO_HZ are set. That same box boots fine
with this patch.This patch comes from the -rt kernel where it has been tested for
several months.Signed-off-by: Steven Rostedt
Signed-off-by: Paul E. McKenney
Signed-off-by: Ingo Molnar
09 Feb, 2008
1 commit
-
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Jan, 2008
2 commits
-
Current idle time in kstat is based on jiffies and is coarse grained.
tick_sched.idle_sleeptime is making some attempt to keep track of idle time
in a fine grained manner. But, it is not handling the time spent in
interrupts fully.Make tick_sched.idle_sleeptime accurate with respect to time spent on
handling interrupts and also add tick_sched.idle_lastupdate, which keeps
track of last time when idle_sleeptime was updated.This statistics will be crucial for cpufreq-ondemand governor, which can
shed some conservative gaurd band that is uses today while setting the
frequency. The ondemand changes that uses the exact idle time is coming
soon.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
I was confused by FSEC = 10^15 NSEC statement, plus small whitespace
fixes. When there's copyright, there should be GPL.Signed-off-by: Pavel Machek
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
11 Oct, 2007
2 commits
-
raise_softirq_irqoff no longer has any modular user.
Signed-off-by: Adrian Bunk
Signed-off-by: David S. Miller -
As noted by Christoph Hellwig, pktgen was the only user so
it can now be removed.[ Add missing cases caught by Adrian Bunk. -DaveM ]
Signed-off-by: Robert Olsson
Signed-off-by: David S. Miller
18 Jul, 2007
1 commit
-
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves. This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.The patch causes all kernel threads to be nonfreezable by default (ie. to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE. It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear. Additionally, it updates documentation to
describe the freezing of tasks more accurately.[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki
Acked-by: Nigel Cunningham
Cc: Pavel Machek
Cc: Oleg Nesterov
Cc: Gautham R Shenoy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Jul, 2007
1 commit
-
Fix ksoftirqd termination on cpu hotplug with naughty real time process.
Assuming the following case:
- Try to hot remove CPU2 from CPU1.
- There is a real time process on CPU2, and that process doesn't sleep at all.
- That rt process and ksoftirqd/2 is migrated to the CPU0Then ksoftirqd/2 can't stop becasue that rt process runs everlastingly on
CPU0, and CPU1 waiting the ksoftirqd/2's termination hangs up. To fix this
problem, set the priority of ksoftirqd/2 to max one before kthread_stop().[akpm@linux-foundation.org: fix warning]
Signed-off-by: Satoru Takeuchi
Cc: Rusty Russell
Cc: Ingo Molnar
Cc: Oleg Nesterov
Cc: Ashok Raj
Cc: Gautham R Shenoy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Jul, 2007
1 commit
-
do not set softirqs to nice +19. _If_ for whatever reason
we missed to process some high-prio softirq and woke up
ksoftirqd, we should give it a fair chance to actually
get some work done, even if the system is under load.Signed-off-by: Ingo Molnar
10 May, 2007
1 commit
-
Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress. This
patch introduces such notifications and causes them to be used during
suspend and resume transitions. It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki
Cc: Gautham R Shenoy
Cc: Pavel Machek
Signed-off-by: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Feb, 2007
2 commits
-
With Ingo Molnar
Add functions to provide dynamic ticks and high resolution timers. The code
which keeps track of jiffies and handles the long idle periods is shared
between tick based and high resolution timer based dynticks. The dyntick
functionality can be disabled on the kernel commandline. Provide also the
infrastructure to support high resolution timers.Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
Cc: john stultz
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Uninline irq_enter(). [dynticks adds more stuff to it]
No functional changes.
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
Cc: john stultz
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Dec, 2006
1 commit
-
It is possible to have tasklets get scheduled before softirqd has had a chance
to spawn on all CPUs. This is totally harmless; after success during action
CPU_UP_PREPARE, action CPU_ONLINE will be called, which immediately wakes
softirqd on the appropriate CPU to process the already pending tasklets. So
there is no danger of having a missed wakeup for any tasklets that were
already pending.In particular, i386 is affected by this during startup, and is visible when
using a very large initrd; during the time it takes for the initrd to be
decompressed, a timer IRQ can come in and schedule RCU callbacks. It is also
possible that resending of a hardware IRQ via a softirq triggers the same bug.Because of different timing conditions, this shows up in all emulators and
virtual machines tested, including Xen, VMware, Virtual PC, and Qemu. It is
also possible to trigger on native hardware with a large enough initrd,
although I don't have a reliable case demonstrating that.Signed-off-by: Zachary Amsden
Cc:
Cc: Ingo Molnar
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Sep, 2006
1 commit
-
Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu()
may fail with small memory. If it happens in initcalls, kernel NULL
pointer dereference happens later. This patch makes crash happen
immediately in such cases. It seems a bit better than getting kernel NULL
pointer dereference later.Cc: Ingo Molnar
Signed-off-by: Akinobu Mita
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Aug, 2006
2 commits
-
The recent changes from irqtrace feature has added overheads to
local_bh_disable and local_bh_enable that reduces UDP performance across
x86_64 and IA64, even though IA64 does not support the irqtrace feature.
Patch in question is[PATCH]lockdep: irqtrace subsystem, core
http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=c
ommit;h=de30a2b355ea85350ca2f58f3b9bf4e5bc007986Prior to this patch, local_bh_disable was a short macro. Now it is a
function which calls __local_bh_disable with added irq flags save and
restore. The irq flags save and restore were also added to
local_bh_enable, probably for injecting the trace irqs code.This overhead is on the generic code path across all architectures. On a
IA_64 test machine (Itanium-2 1.6 GHz) running a benchmark like netperf's
UDP streaming test, the added overhead results in a drop of 3% in
throughput, as udp_sendmsg calls the local_bh_enable/disable several times.Other workloads that have heavy usages of local_bh_enable/disable could
also be affected. The patch ideally should not have affected IA-64
performance as it does not have IRQ tracing support. A significant portion
of the overhead is in the added irq flags save and restore, which I think
is not needed if IRQ tracing is unused. A suggested patch is attached
below that recovers the lost performance. However, the "ifdef"s in the
patch are a bit ugly.Signed-off-by: Tim Chen
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Few of the callback functions and notifier blocks that are associated with cpu
notifications incorrectly have __devinit and __devinitdata. They should be
__cpuinit and __cpuinitdata instead.It makes no functional difference but wastes text area when CONFIG_HOTPLUG is
enabled and CONFIG_HOTPLUG_CPU is not.This patch fixes all those instances.
Signed-off-by: Chandra Seetharaman
Cc: Ashok Raj
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jul, 2006
1 commit
-
Christoph Hellwig:
open_softirq just enables a softirq. The softirq array is statically
allocated so to add a new one you would have to patch the kernel. So
there's no point to keep this export at all as any user would have to
patch the enum in include/linux/interrupt.h anyway.Signed-off-by: Adrian Bunk
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jul, 2006
1 commit
-
This patch marks an unused export as EXPORT_UNUSED_SYMBOL.
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jul, 2006
2 commits
-
At the moment, powerpc and s390 have their own versions of do_softirq which
include local_bh_disable() and __local_bh_enable() calls. They end up
calling __do_softirq (in kernel/softirq.c) which also does
local_bh_disable/enable.Apparently the two levels of disable/enable trigger a warning from some
validation code that Ingo is working on, and he would like to see the outer
level removed. But to do that, we have to move the account_system_vtime
calls that are currently in the arch do_softirq() implementations for
powerpc and s390 into the generic __do_softirq() (this is a no-op for other
archs because account_system_vtime is defined to be an empty inline
function on all other archs). This patch does that.Signed-off-by: Paul Mackerras
Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Accurate hard-IRQ-flags and softirq-flags state tracing.
This allows us to attach extra functionality to IRQ flags on/off
events (such as trace-on/off).Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
