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* snapshot: Use pm_mutex for mutual exclusionRafael J. Wysocki2008-07-161-26/+42
| | | | | | | | | | | | | | | | We can avoid taking the BKL in snapshot_ioctl() if pm_mutex is used to prevent the ioctls from being executed concurrently. In addition, although it is only possible to open /dev/snapshot once, the task which has done that may spawn a child that will inherit the open descriptor, so in theory they can call snapshot_write(), snapshot_read() and snapshot_release() concurrently. pm_mutex can also be used for mutual exclusion in such cases. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Len Brown <len.brown@intel.com>
* snapshot: Push BKL down into ioctl handlersAlan Cox2008-07-161-4/+7
| | | | | | | | | Push BKL down into ioctl handlers - snapshot device. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* Freezer: Introduce PF_FREEZER_NOSIGRafael J. Wysocki2008-07-162-56/+43
| | | | | | | | | | | | | | | | | | | | | The freezer currently attempts to distinguish kernel threads from user space tasks by checking if their mm pointer is unset and it does not send fake signals to kernel threads. However, there are kernel threads, mostly related to networking, that behave like user space tasks and may want to be sent a fake signal to be frozen. Introduce the new process flag PF_FREEZER_NOSIG that will be set by default for all kernel threads and make the freezer only send fake signals to the tasks having PF_FREEZER_NOSIG unset. Provide the set_freezable_with_signal() function to be called by the kernel threads that want to be sent a fake signal for freezing. This patch should not change the freezer's observable behavior. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Len Brown <len.brown@intel.com>
* force offline the processor during hot-removalZhang Rui2008-07-161-0/+1
| | | | | | | | | | | The ACPI device node for the cpu has already been unregistered when acpi_processor_handle_eject is called. Thus we should offline the cpu and continue, rather than a failure here. http://bugzilla.kernel.org/show_bug.cgi?id=9772 Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* generic ipi function calls: wait on alloc failure fallbackJeremy Fitzhardinge2008-07-151-0/+1
| | | | | | | | | | When a GFP_ATOMIC allocation fails, it falls back to allocating the data on the stack and converting it to a waiting call. Make sure we actually wait in this case. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'generic-ipi-for-linus' of ↵Linus Torvalds2008-07-157-8/+391
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'generic-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits) generic-ipi: more merge fallout generic-ipi: merge fix x86, visws: use mach-default/entry_arch.h x86, visws: fix generic-ipi build generic-ipi: fixlet generic-ipi: fix s390 build bug generic-ipi: fix linux-next tree build failure fix: "smp_call_function: get rid of the unused nonatomic/retry argument" fix: "smp_call_function: get rid of the unused nonatomic/retry argument" fix "smp_call_function: get rid of the unused nonatomic/retry argument" on_each_cpu(): kill unused 'retry' parameter smp_call_function: get rid of the unused nonatomic/retry argument sh: convert to generic helpers for IPI function calls parisc: convert to generic helpers for IPI function calls mips: convert to generic helpers for IPI function calls m32r: convert to generic helpers for IPI function calls arm: convert to generic helpers for IPI function calls alpha: convert to generic helpers for IPI function calls ia64: convert to generic helpers for IPI function calls powerpc: convert to generic helpers for IPI function calls ... Fix trivial conflicts due to rcu updates in kernel/rcupdate.c manually
| * Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar2008-07-157-8/+390
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * fix: "smp_call_function: get rid of the unused nonatomic/retry argument"Ingo Molnar2008-06-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | fix: kernel/smp.c: In function 'smp_call_function_mask': kernel/smp.c:303: error: too many arguments to function 'smp_call_function_single' Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * on_each_cpu(): kill unused 'retry' parameterJens Axboe2008-06-264-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * smp_call_function: get rid of the unused nonatomic/retry argumentJens Axboe2008-06-263-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | It's never used and the comments refer to nonatomic and retry interchangably. So get rid of it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| | * Add generic helpers for arch IPI function callsJens Axboe2008-06-262-0/+384
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds kernel/smp.c which contains helpers for IPI function calls. In addition to supporting the existing smp_call_function() in a more efficient manner, it also adds a more scalable variant called smp_call_function_single() for calling a given function on a single CPU only. The core of this is based on the x86-64 patch from Nick Piggin, lots of changes since then. "Alan D. Brunelle" <Alan.Brunelle@hp.com> has contributed lots of fixes and suggestions as well. Also thanks to Paul E. McKenney <paulmck@linux.vnet.ibm.com> for reviewing RCU usage and getting rid of the data allocation fallback deadlock. Acked-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | Merge branch 'core/rcu' into core/rcu-for-linusIngo Molnar2008-07-157-79/+633
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| * | rcu classic: update qlen when cpu offlineLai Jiangshan2008-07-131-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When callbacks are moved from offline cpu to this cpu, the qlen field of this rdp should be updated. [ Paul E. McKenney: ] The effect of this bug would be for force_quiescent_state() to be invoked when it should not and vice versa -- wasting cycles in the first case and letting RCU callbacks remain piled up in the second case. The bug is thus "benign" in that it does not result in premature grace-period termination, but should of course be fixed nonetheless. Preemption is disabled by the caller's get_cpu_var(), so we are guaranteed to remain on the same CPU, as required. The local_irq_disable() is indeed needed, otherwise, an interrupt might invoke call_rcu() or call_rcu_bh(), which could cause that interrupt's increment of ->qlen to be lost. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Merge branch 'linus' into core/rcuIngo Molnar2008-07-1111-21/+66
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: include/linux/rculist.h kernel/rcupreempt.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | rcu: make rcutorture even more vicious: invoke RCU readers from irq handlers ↵Paul E. McKenney2008-06-261-4/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (timers) This patch allows torturing RCU from irq handlers (timers, in this case). A new module parameter irqreader enables such additional torturing, and is enabled by default. Variants of RCU that do not tolerate readers being called from irq handlers (e.g., SRCU) ignore irqreader. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: josh@freedesktop.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: dino@in.ibm.com Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Cc: vegard.nossum@gmail.com Cc: adobriyan@gmail.com Cc: oleg@tv-sign.ru Cc: bunk@kernel.org Cc: rjw@sisk.pl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | Merge commit 'v2.6.26-rc8' into core/rcuIngo Molnar2008-06-264-30/+83
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| * | | rcu: make quiescent rcutorture less power-hungryPaul E. McKenney2008-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch aligns the rcutorture wakeup times to align with all other multiple-of-a-second wakeups to further decrease power consumption. Suggested-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: josh@freedesktop.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: dino@in.ibm.com Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Cc: vegard.nossum@gmail.com Cc: adobriyan@gmail.com Cc: oleg@tv-sign.ru Cc: bunk@kernel.org Cc: rjw@sisk.pl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | rcu, rcutorture: make quiescent rcutorture less power-hungryPaul E. McKenney2008-06-241-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: josh@freedesktop.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: dino@in.ibm.com Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Cc: vegard.nossum@gmail.com Cc: adobriyan@gmail.com Cc: oleg@tv-sign.ru Cc: bunk@kernel.org Cc: rjw@sisk.pl Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | Merge branch 'linus' into core/rcuIngo Molnar2008-06-235-37/+91
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| * | | | rcu: make rcutorture more vicious: reinstate boot-time testingPaul E. McKenney2008-06-192-1/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch re-institutes the ability to build rcutorture directly into the Linux kernel. The reason that this capability was removed was that this could result in your kernel being pretty much useless, as rcutorture would be running starting from early boot. This problem has been avoided by (1) making rcutorture run only three seconds of every six by default, (2) adding a CONFIG_RCU_TORTURE_TEST_RUNNABLE that permits rcutorture to be quiesced at boot time, and (3) adding a sysctl in /proc named /proc/sys/kernel/rcutorture_runnable that permits rcutorture to be quiesced and unquiesced when built into the kernel. Please note that this /proc file is -not- available when rcutorture is built as a module. Please also note that to get the earlier take-no-prisoners behavior, you must use the boot command line to set rcutorture's "stutter" parameter to zero. The rcutorture quiescing mechanism is currently quite crude: loops in each rcutorture process that poll a global variable once per tick. Suggestions for improvement are welcome. The default action will be to reduce the polling rate to a few times per second. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Suggested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | rcu: make rcutorture more vicious: add stutter featurePaul E. McKenney2008-06-181-3/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch takes a step towards making rcutorture more brutal by allowing the test to be automatically periodically paused, with the default being to run the test for five seconds then pause for five seconds and repeat. This behavior can be controlled using a new "stutter" module parameter, so that "stutter=0" gives the old default behavior of running continuously. Starting and stopping rcutorture more heavily stresses RCU's interaction with the scheduler, as well as exercising more paths through the grace-period detection code. Note that the default to "shuffle_interval" has also been adjusted from 5 seconds to 3 seconds to provide varying overlap with the "stutter" interval. I am still unable to provoke the failures that Alexey has been seeing, even with this patch, but will be doing a few additional things to beef up rcutorture. Suggested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | rcutorture: WARN_ON_ONCE(1) when detecting an errorIngo Molnar2008-06-181-0/+1
| | | | | | | | | | | | | | | | | | | | this makes it easier for automated tests to pick up such failures.
| * | | | Merge branch 'linus' into core/rcuIngo Molnar2008-06-1621-805/+342
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| * | | | | rcu: remove unused field struct rcu_data::rcu_taskletLai Jiangshan2008-06-161-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since softirq works for rcu reclaimer, rcu_tasklet is unused now. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | rcu: remove duplicated include in kernel/rcupreempt.cHuang Weiyi2008-05-191-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Removed duplicated include file <linux/rcupdate.h> in kernel/rcupreempt.c. Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | rcu: remove duplicated include in kernel/rcupreempt_trace.cHuang Weiyi2008-05-191-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Removed duplicated include file <linux/rcupdate.h> in kernel/rcupreempt_trace.c Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | rcu: fix rcu_try_flip_waitack_needed() to prevent grace-period stallPaul E. McKenney2008-05-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment was correct -- need to make the code match the comment. Without this patch, if a CPU goes dynticks idle (and stays there forever) in just the right phase of preemptible-RCU grace-period processing, grace periods stall. The offending sequence of events (courtesy of Promela/spin, at least after I got the liveness criterion coded correctly...) is as follows: o CPU 0 is in dynticks-idle mode. Its dynticks_progress_counter is (say) 10. o CPU 0 takes an interrupt, so rcu_irq_enter() increments CPU 0's dynticks_progress_counter to 11. o CPU 1 is doing RCU grace-period processing in rcu_try_flip_idle(), sees rcu_pending(), so invokes dyntick_save_progress_counter(), which in turn takes a snapshot of CPU 0's dynticks_progress_counter into CPU 0's rcu_dyntick_snapshot -- now set to 11. CPU 1 then updates the RCU grace-period state to rcu_try_flip_waitack(). o CPU 0 returns from its interrupt, so rcu_irq_exit() increments CPU 0's dynticks_progress_counter to 12. o CPU 1 later invokes rcu_try_flip_waitack(), which notices that CPU 0 has not yet responded, and hence in turn invokes rcu_try_flip_waitack_needed(). This function examines the state of CPU 0's dynticks_progress_counter and rcu_dyntick_snapshot variables, which it copies to curr (== 12) and snap (== 11), respectively. Because curr!=snap, the first condition fails. Because curr-snap is only 1 and snap is odd, the second condition fails. rcu_try_flip_waitack_needed() therefore incorrectly concludes that it must wait for CPU 0 to explicitly acknowledge the counter flip. o CPU 0 remains forever in dynticks-idle mode, never taking any more hardware interrupts or any NMIs, and never running any more tasks. (Of course, -something- will usually eventually happen, which might be why we haven't seen this one in the wild. Still should be fixed!) Therefore the grace period never ends. Fix is to make the code match the comment, as shown below. With this fix, the above scenario would be satisfied with curr being even, and allow the grace period to proceed. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Josh Triplett <josh@kernel.org> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | rcu: split list.h and move rcu-protected lists into rculist.hFranck Bui-Huu2008-05-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move rcu-protected lists from list.h into a new header file rculist.h. This is done because list are a very used primitive structure all over the kernel and it's currently impossible to include other header files in this list.h without creating some circular dependencies. For example, list.h implements rcu-protected list and uses rcu_dereference() without including rcupdate.h. It actually compiles because users of rcu_dereference() are macros. Others RCU functions could be used too but aren't probably because of this. Therefore this patch creates rculist.h which includes rcupdates without to many changes/troubles. Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | rcu: add call_rcu_sched() and friends to rcutorturePaul E. McKenney2008-05-191-3/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add entry to rcu_torture_ops allowing the correct barrier function to be used upon exit from rcutorture. Also add torture options for the new call_rcu_sched() API. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | rcu: add rcu_barrier_sched() and rcu_barrier_bh()Paul E. McKenney2008-05-191-6/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add rcu_barrier_sched() and rcu_barrier_bh(). With these in place, rcutorture no longer gives the occasional oops when repeatedly starting and stopping torturing rcu_bh. Also adds the API needed to flush out pre-existing call_rcu_sched() callbacks. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | rcu: add memory barriers and comments to rcu_check_callbacks()Paul E. McKenney2008-05-191-1/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add comments to the logic that infers quiescent states when interrupting from either user mode or the idle loop. Also add a memory barrier: it appears that James Huang was in fact onto something, as the scheduler is much less synchronization happy than it once was, so we can no longer rely on its memory barriers in all cases. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reported-by: James Huang <jamesclhuang@yahoo.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | rcu: add call_rcu_sched()Paul E. McKenney2008-05-192-62/+372
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fourth cut of patch to provide the call_rcu_sched(). This is again to synchronize_sched() as call_rcu() is to synchronize_rcu(). Should be fine for experimental and -rt use, but not ready for inclusion. With some luck, I will be able to tell Andrew to come out of hiding on the next round. Passes multi-day rcutorture sessions with concurrent CPU hotplugging. Fixes since the first version include a bug that could result in indefinite blocking (spotted by Gautham Shenoy), better resiliency against CPU-hotplug operations, and other minor fixes. Fixes since the second version include reworking grace-period detection to avoid deadlocks that could happen when running concurrently with CPU hotplug, adding Mathieu's fix to avoid the softlockup messages, as well as Mathieu's fix to allow use earlier in boot. Fixes since the third version include a wrong-CPU bug spotted by Andrew, getting rid of the obsolete synchronize_kernel API that somehow snuck back in, merging spin_unlock() and local_irq_restore() in a few places, commenting the code that checks for quiescent states based on interrupting from user-mode execution or the idle loop, removing some inline attributes, and some code-style changes. Known/suspected shortcomings: o I still do not entirely trust the sleep/wakeup logic. Next step will be to use a private snapshot of the CPU online mask in rcu_sched_grace_period() -- if the CPU wasn't there at the start of the grace period, we don't need to hear from it. And the bit about accounting for changes in online CPUs inside of rcu_sched_grace_period() is ugly anyway. o It might be good for rcu_sched_grace_period() to invoke resched_cpu() when a given CPU wasn't responding quickly, but resched_cpu() is declared static... This patch also fixes a long-standing bug in the earlier preemptable-RCU implementation of synchronize_rcu() that could result in loss of concurrent external changes to a task's CPU affinity mask. I still cannot remember who reported this... Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | rcupreempt: remove duplicate prototypesSteven Rostedt2008-05-191-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rcu_batches_completed and rcu_patches_completed_bh are both declared in rcuclassic.h and rcupreempt.h. This patch removes the extra prototypes for them from rcupdate.h. rcu_batches_completed_bh is defined as a static inline in the rcupreempt.h header file. Trying to export this as EXPORT_SYMBOL_GPL causes linking problems with the powerpc linker. There's no need to export a static inlined function. Modules must be compiled with the same type of RCU implementation as the kernel they are for. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | Merge branch 'timers/for-linus' of ↵Linus Torvalds2008-07-153-5/+13
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Gleixner2008-07-143-5/+13
| |\ \ \ \ \ \ \ \ \ | | | | | |_|_|_|/ / | | | | |/| | | | | | | | | | | | | | | 'timers/nohz', 'timers/clocksource' and 'timers/posixtimers' into timers/for-linus
| | | | | * | | | | posix-timers: print RT watchdog messageHiroshi Shimamoto2008-05-241-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's useful to detect which process is killed by RT watchdog. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | | * | | | | | | nohz: don't stop idle tick if softirqs are pending.Heiko Carstens2008-07-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case a cpu goes idle but softirqs are pending only an error message is printed to the console. It may take a very long time until the pending softirqs will finally be executed. Worst case would be a hanging system. With this patch the timer tick just continues and the softirqs will be executed after the next interrupt. Still a delay but better than a hanging system. Currently we have at least two device drivers on s390 which under certain circumstances schedule a tasklet from process context. This is a reason why we can end up with pending softirqs when going idle. Fixing these drivers seems to be non-trivial. However there is no question that the drivers should be fixed. This patch shouldn't be considered as a bug fix. It just is intended to keep a system running even if device drivers are buggy. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Glauber <jan.glauber@de.ibm.com> Cc: Stefan Weinhuber <wein@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | | | | | nohz: reduce jiffies polling overheadIngo Molnar2008-05-301-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | 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 'genirq' of ↵Linus Torvalds2008-07-152-9/+83
|\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'genirq' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: remove extraneous checks in manage.c genirq: Expose default irq affinity mask (take 3)
| * | | | | | | | | | genirq: remove extraneous checks in manage.cThomas Gleixner2008-07-101-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In http://bugzilla.kernel.org/show_bug.cgi?id=9580 it was pointed out that the desc->chip checks are extraneous. In fact these are left overs from early development and can be removed safely. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | | | | genirq: Expose default irq affinity mask (take 3)Max Krasnyansky2008-06-052-6/+81
| | |_|/ / / / / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current IRQ affinity interface does not provide a way to set affinity for the IRQs that will be allocated/activated in the future. This patch creates /proc/irq/default_smp_affinity that lets users set default affinity mask for the newly allocated IRQs. Changing the default does not affect affinity masks for the currently active IRQs, they have to be changed explicitly. Updated based on Paul J's comments and added some more documentation. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Cc: pj@sgi.com Cc: a.p.zijlstra@chello.nl Cc: tglx@linutronix.de Cc: rdunlap@xenotime.net Cc: mingo@elte.hu Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | | | | | Merge branch 'core/stacktrace' of ↵Linus Torvalds2008-07-152-17/+62
|\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core/stacktrace' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: generic-ipi: powerpc/generic-ipi tree build failure stacktrace: fix build failure on sparc64 stacktrace: export save_stack_trace[_tsk] stacktrace: fix modular build, export print_stack_trace and save_stack_trace backtrace: replace timer with tasklet + completions stacktrace: add saved stack traces to backtrace self-test stacktrace: print_stack_trace() cleanup debugging: make stacktrace independent from DEBUG_KERNEL stacktrace: don't crash on invalid stack trace structs
| * | | | | | | | | | stacktrace: fix modular build, export print_stack_trace and save_stack_traceIngo Molnar2008-06-301-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fix: ERROR: "print_stack_trace" [kernel/backtracetest.ko] undefined! ERROR: "save_stack_trace" [kernel/backtracetest.ko] undefined! Signed-off-by: Ingo Molnar <mingo@elte.hu> and fix: Building modules, stage 2. MODPOST 376 modules ERROR: "print_stack_trace" [kernel/backtracetest.ko] undefined! make[1]: *** [__modpost] Error 1 Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | backtrace: replace timer with tasklet + completionsVegard Nossum2008-06-271-11/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On qemu, the backtrace would show up _after_ the "end of backtrace testing" message. This patch changes it to use completions instead, which will guarantee that no such race exists. Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | stacktrace: add saved stack traces to backtrace self-testVegard Nossum2008-06-271-1/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds saved stack-traces to the backtrace suite of self-tests. Note that we don't depend on or unconditionally enable CONFIG_STACKTRACE because not all architectures may have it (and we still want to enable the other tests for those architectures). Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | stacktrace: print_stack_trace() cleanupVegard Nossum2008-06-131-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - shorter code and better atomicity with regards to printk(). (It's been tested with the backtrace self-test code on i386 and x86_64.) Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | stacktrace: don't crash on invalid stack trace structsJohannes Berg2008-05-241-0/+3
| | |_|_|_|/ / / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes the stacktrace printout code \warn when the entries pointer is unset rather than crashing when trying to access it in an attempt to make it a bit more robust. I was saving a stacktrace into an skb and forgot to copy it across skb copies... I have since fixed the code, but it would have been easier had the kernel not crashed in an interrupt. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | | | | | Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds2008-07-143-22/+2
|\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * '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. ...
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