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* rcu: add support for dynamic ticks and preempt rcuSteven Rostedt2008-02-291-0/+1
| | | | | | | | | | | | | | | 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 <srostedt@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* kernel: remove fastcall in kernel/*Harvey Harrison2008-02-081-4/+4
| | | | | | | | [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> 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>
* time: track accurate idle time with tick_sched.idle_sleeptimeVenki Pallipadi2008-01-301-1/+6
| | | | | | | | | | | | | | | | | | | | | 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 <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* time: more timer related cleanupsPavel Machek2008-01-301-1/+3
| | | | | | | | | 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 <pavel@suse.cz> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* [KERNEL]: Unexport raise_softirq_irqoffAdrian Bunk2007-10-101-2/+0
| | | | | | | raise_softirq_irqoff no longer has any modular user. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [SOFTIRQ]: Remove do_softirq() symbol export.Robert Olsson2007-10-101-2/+0
| | | | | | | | | | 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 <robert.olsson@its.uu.se> Signed-off-by: David S. Miller <davem@davemloft.net>
* Freezer: make kernel threads nonfreezable by defaultRafael J. Wysocki2007-07-171-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <rjw@sisk.pl> Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpu hotplug: fix ksoftirqd termination on cpu hotplug with naughty realtime ↵Satoru Takeuchi2007-07-161-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | process 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 CPU0 Then 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 <takeuchi_satoru@jp.fujitsu.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: do not set softirqs to nice +19Ingo Molnar2007-07-091-1/+0
| | | | | | | | | 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 <mingo@elte.hu>
* Add suspend-related notifications for CPU hotplugRafael J. Wysocki2007-05-091-0/+4
| | | | | | | | | | | | | | | | | | | | | 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 <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] tick-management: dyntick / highres functionalityThomas Gleixner2007-02-161-3/+12
| | | | | | | | | | | | | | | | | With Ingo Molnar <mingo@elte.hu> 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 <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> 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>
* [PATCH] uninline irq_enter()Ingo Molnar2007-02-161-0/+10
| | | | | | | | | | | | | Uninline irq_enter(). [dynticks adds more stuff to it] No functional changes. 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>
* [PATCH] softirq: remove BUG_ONs which can incorrectly triggerZachary Amsden2006-12-071-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 <zach@vmware.com> Cc: <caglar@pardus.org.tr> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] check return value of cpu_callbackAkinobu Mita2006-09-291-1/+3
| | | | | | | | | | | | | 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 <mingo@elte.hu> Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Reducing local_bh_enable/disable overhead in irqtraceTim Chen2006-07-311-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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=de30a2b355ea85350ca2f58f3b9bf4e5bc007986 Prior 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 <tim.c.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hotplug: replace __devinit* with __cpuinit* for cpu notificationsChandra Seetharaman2006-07-311-2/+2
| | | | | | | | | | | | | | | | 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 <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] unexport open_softirqAdrian Bunk2006-07-141-2/+0
| | | | | | | | | | | | | 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 <bunk@stusta.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kernel/softirq.c: EXPORT_UNUSED_SYMBOLAdrian Bunk2006-07-101-1/+1
| | | | | | | | This patch marks an unused export as EXPORT_UNUSED_SYMBOL. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: irqtrace subsystem, move account_system_vtime() calls into ↵Paul Mackerras2006-07-031-0/+4
| | | | | | | | | | | | | | | | | | | | | | kernel/softirq.c 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 <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: irqtrace subsystem, coreIngo Molnar2006-07-031-19/+118
| | | | | | | | | | | | 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 <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17Chandra Seetharaman2006-06-271-1/+1
| | | | | | | | | This patch reverts notifier_block changes made in 2.6.17 Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hotplug: revert init patch submitted for 2.6.17Chandra Seetharaman2006-06-271-1/+1
| | | | | | | | | | | | | | | | | | | | | In 2.6.17, there was a problem with cpu_notifiers and XFS. I provided a band-aid solution to solve that problem. In the process, i undid all the changes you both were making to ensure that these notifiers were available only at init time (unless CONFIG_HOTPLUG_CPU is defined). We deferred the real fix to 2.6.18. Here is a set of patches that fixes the XFS problem cleanly and makes the cpu notifiers available only at init time (unless CONFIG_HOTPLUG_CPU is defined). If CONFIG_HOTPLUG_CPU is defined then cpu notifiers are available at run time. This patch reverts the notifier_call changes made in 2.6.17 Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hotplug: fix CPU_UP_CANCEL handlingHeiko Carstens2006-06-251-0/+2
| | | | | | | | | | | | | | If a cpu hotplug callback fails on CPU_UP_PREPARE, all callbacks will be called with CPU_UP_CANCELED. A few of these callbacks assume that on CPU_UP_PREPARE a pointer to task has been stored in a percpu array. This assumption is not true if CPU_UP_PREPARE fails and the following calls to kthread_bind() in CPU_UP_CANCELED will cause an addressing exception because of passing a NULL pointer. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Remove __devinit and __cpuinit from notifier_call definitionsChandra Seetharaman2006-04-261-1/+1
| | | | | | | | | | | | | Few of the notifier_chain_register() callers use __init in the definition of notifier_call. It is incorrect as the function definition should be available after the initializations (they do not unregister them during initializations). This patch fixes all such usages to _not_ have the notifier_call __init section. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Remove __devinitdata from notifier block definitionsChandra Seetharaman2006-04-261-1/+1
| | | | | | | | | | | | | | | | Few of the notifier_chain_register() callers use __devinitdata in the definition of notifier_block data structure. It is incorrect as the data structure should be available after the initializations (they do not unregister them during initializations). This was leading to an oops when notifier_chain_register() call is invoked for those callback chains after initialization. This patch fixes all such usages to _not_ have the notifier_block data structure in the init data section. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] on_each_cpu(): disable local interruptsAndrew Morton2006-03-221-0/+20
| | | | | | | | | | | | | | | | | | | When on_each_cpu() runs the callback on other CPUs, it runs with local interrupts disabled. So we should run the function with local interrupts disabled on this CPU, too. And do the same for UP, so the callback is run in the same environment on both UP and SMP. (strictly it should do preempt_disable() too, but I think local_irq_disable is sufficiently equivalent). Also uninlines on_each_cpu(). softirq.c was the most appropriate file I could find, but it doesn't seem to justify creating a new file. Oh, and fix up that comment over (under?) x86's smp_call_function(). It drives me nuts. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hoptlug: avoid usage of smp_processor_id() in preemptible codeHeiko Carstens2005-11-071-1/+2
| | | | | | | | | | | | | | | | | | | | Replace smp_processor_id() with any_online_cpu(cpu_online_map) in order to avoid lots of "BUG: using smp_processor_id() in preemptible [00000001] code:..." messages in case taking a cpu online fails. All the traces start at the last notifier_call_chain(...) in kernel/cpu.c. Since we hold the cpu_control semaphore it shouldn't be any problem to access cpu_online_map. The reason why cpu_up failed is simply that the cpu that was supposed to be taken online wasn't even there. That is because on s390 we never know when a new cpu comes and therefore cpu_possible_map consists of only ones and doesn't reflect reality. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86-64: Some cleanup and optimization to the processor data area.Andi Kleen2005-09-121-1/+1
| | | | | | | | | - Remove unused irqrsp field - Remove pda->me - Optimize set_softirq_pending slightly Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] revert bogus softirq changesAndrew Morton2005-07-301-2/+2
| | | | | | | | | This snuck in with an x86_64 change. Thanks to Richard Purdie <rpurdie@rpsys.net> for spotting it. Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Switch to the interrupt stack when running a softirq in ↵Andi Kleen2005-07-281-2/+2
| | | | | | | | | | | | | local_bh_enable() This avoids some potential stack overflows with very deep softirq callchains. i386 does this too. TOADD CFI annotation Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+496
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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