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2008-09-22sched: turn off WAKEUP_OVERLAPIngo Molnar
WAKEUP_OVERLAP is not a winner on a 16way box, running psql+sysbench: .27-rc7-NO_WAKEUP_OVERLAP .27-rc7-WAKEUP_OVERLAP ------------------------------------------------- 1: 694 811 +14.39% 2: 1454 1427 -1.86% 4: 3017 3070 +1.70% 8: 5694 5808 +1.96% 16: 10592 10612 +0.19% 32: 9693 9647 -0.48% 64: 8507 8262 -2.97% 128: 8402 7087 -18.55% 256: 8419 5124 -64.30% 512: 7990 3671 -117.62% ------------------------------------------------- SUM: 64466 55524 -16.11% ... so turn it off by default. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-22sched: wakeup preempt when small overlapPeter Zijlstra
Lin Ming reported a 10% OLTP regression against 2.6.27-rc4. The difference seems to come from different preemption agressiveness, which affects the cache footprint of the workload and its effective cache trashing. Aggresively preempt a task if its avg overlap is very small, this should avoid the task going to sleep and find it still running when we schedule back to it - saving a wakeup. Reported-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-19Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: fix deadlock in setting scheduler parameter to zero sched: fix 2.6.27-rc5 couldn't boot on tulsa machine randomly
2008-09-19Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clockevents: make device shutdown robust clocksource, acpi_pm.c: fix check for monotonicity clockevents: remove WARN_ON which was used to gather information
2008-09-16clockevents: make device shutdown robustThomas Gleixner
The device shut down does not cleanup the next_event variable of the clock event device. So when the device is reactivated the possible stale next_event value can prevent the device to be reprogrammed as it claims to wait on a event already. This is the root cause of the resurfacing suspend/resume problem, where systems need key press to come back to life. Fix this by setting next_event to KTIME_MAX when the device is shut down. Use a separate function for shutdown which takes care of that and only keep the direct set mode call in the broadcast code, where we can not touch the next_event value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-14Merge branch 'linus' into x86/iommuIngo Molnar
Conflicts: lib/swiotlb.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-13cpuset: avoid changing cpuset's cpus when -errno returnedLi Zefan
After the patch: commit 0b2f630a28d53b5a2082a5275bc3334b10373508 Author: Miao Xie <miaox@cn.fujitsu.com> Date: Fri Jul 25 01:47:21 2008 -0700 cpusets: restructure the function update_cpumask() and update_nodemask() It might happen that 'echo 0 > /cpuset/sub/cpus' returned failure but 'cpus' has been changed, because cpus was changed before calling heap_init() which may return -ENOMEM. This patch restores the orginal behavior. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-11Merge commit 'v2.6.27-rc6' into sched/develIngo Molnar
2008-09-11sched: fix deadlock in setting scheduler parameter to zeroHiroshi Shimamoto
Andrei Gusev wrote: > I played witch scheduler settings. After doing something like: > echo -n 1000000 >sched_rt_period_us > > command is locked. I found in kernel.log: > > Sep 11 00:39:34 zaratustra > Sep 11 00:39:34 zaratustra Pid: 4495, comm: bash Tainted: G W > (2.6.26.3 #12) > Sep 11 00:39:34 zaratustra EIP: 0060:[<c0213fc7>] EFLAGS: 00210246 CPU: 0 > Sep 11 00:39:34 zaratustra EIP is at div64_u64+0x57/0x80 > Sep 11 00:39:34 zaratustra EAX: 0000389f EBX: 00000000 ECX: 00000000 > EDX: 00000000 > Sep 11 00:39:34 zaratustra ESI: d9800000 EDI: d9800000 EBP: 0000389f > ESP: ea7a6edc > Sep 11 00:39:34 zaratustra DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 > Sep 11 00:39:34 zaratustra Process bash (pid: 4495, ti=ea7a6000 > task=ea744000 task.ti=ea7a6000) > Sep 11 00:39:34 zaratustra Stack: 00000000 000003e8 d9800000 0000389f > c0119042 00000000 00000000 00000001 > Sep 11 00:39:34 zaratustra 00000000 00000000 ea7a6f54 00010000 00000000 > c04d2e80 00000001 000e7ef0 > Sep 11 00:39:34 zaratustra c01191a3 00000000 00000000 ea7a6fa0 00000001 > ffffffff c04d2e80 ea5b2480 > Sep 11 00:39:34 zaratustra Call Trace: > Sep 11 00:39:34 zaratustra [<c0119042>] __rt_schedulable+0x52/0x130 > Sep 11 00:39:34 zaratustra [<c01191a3>] sched_rt_handler+0x83/0x120 > Sep 11 00:39:34 zaratustra [<c01a76a6>] proc_sys_call_handler+0xb6/0xd0 > Sep 11 00:39:34 zaratustra [<c01a76c0>] proc_sys_write+0x0/0x20 > Sep 11 00:39:34 zaratustra [<c01a76d9>] proc_sys_write+0x19/0x20 > Sep 11 00:39:34 zaratustra [<c016cc68>] vfs_write+0xa8/0x140 > Sep 11 00:39:34 zaratustra [<c016cdd1>] sys_write+0x41/0x80 > Sep 11 00:39:34 zaratustra [<c0103051>] sysenter_past_esp+0x6a/0x91 > Sep 11 00:39:34 zaratustra ======================= > Sep 11 00:39:34 zaratustra Code: c8 41 0f ad f3 d3 ee f6 c1 20 0f 45 de > 31 f6 0f ad ef d3 ed f6 c1 20 0f 45 fd 0f 45 ee 31 c9 39 eb 89 fe 89 ea > 77 08 89 e8 31 d2 <f7> f3 89 c1 89 f0 8b 7c 24 08 f7 f3 8b 74 24 04 89 > ca 8b 1c 24 > Sep 11 00:39:34 zaratustra EIP: [<c0213fc7>] div64_u64+0x57/0x80 SS:ESP > 0068:ea7a6edc > Sep 11 00:39:34 zaratustra ---[ end trace 4eaa2a86a8e2da22 ]--- fix the boundary condition. sysctl_sched_rt_period=0 makes exception at to_ratio(). Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-11sched: fix 2.6.27-rc5 couldn't boot on tulsa machine randomlyZhang, Yanmin
On my tulsa x86-64 machine, kernel 2.6.25-rc5 couldn't boot randomly. Basically, function __enable_runtime forgets to reset rt_rq->rt_throttled to 0. When every cpu is up, per-cpu migration_thread is created and it runs very fast, sometimes to mark the corresponding rt_rq->rt_throttled to 1 very quickly. After all cpus are up, with below calling chain: sched_init_smp => arch_init_sched_domains => build_sched_domains => ... => cpu_attach_domain => rq_attach_root => set_rq_online => ... => _enable_runtime _enable_runtime is called against every rt_rq again, so rt_rq->rt_time is reset to 0, but rt_rq->rt_throttled might be still 1. Later on function do_sched_rt_period_timer couldn't reset it, and all RT tasks couldn't be scheduled to run on that cpu. here is RT task migration_thread which is woken up when a task is migrated to another cpu. Below patch fixes it against 2.6.27-rc5. Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-10Merge commit 'v2.6.27-rc6' into x86/unify-cpu-detectIngo Molnar
Conflicts: arch/x86/kernel/cpu/amd.c arch/x86/kernel/cpu/common.c arch/x86/kernel/cpu/common_64.c arch/x86/kernel/cpu/feature_names.c include/asm-x86/cpufeature.h Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-10Merge commit 'v2.6.27-rc6' into x86/iommuIngo Molnar
2008-09-10Merge commit 'v2.6.27-rc6' into core/rcuIngo Molnar
2008-09-09clockevents: remove WARN_ON which was used to gather informationThomas Gleixner
The issue of the endless reprogramming loop due to a too small min_delta_ns was fixed with the previous updates of the clock events code, but we had no information about the spread of this problem. I added a WARN_ON to get automated information via kerneloops.org and to get some direct reports, which allowed me to analyse the affected machines. The WARN_ON has served its purpose and would be annoying for a release kernel. Remove it and just keep the information about the increase of the min_delta_ns value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-08Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: arch_reinit_sched_domains() must destroy domains to force rebuild sched, cpuset: rework sched domains and CPU hotplug handling (v4)
2008-09-08kernel/cpu.c: create a CPU_STARTING cpu_chain notifierManfred Spraul
Right now, there is no notifier that is called on a new cpu, before the new cpu begins processing interrupts/softirqs. Various kernel function would need that notification, e.g. kvm works around by calling smp_call_function_single(), rcu polls cpu_online_map. The patch adds a CPU_STARTING notification. It also adds a helper function that sends the message to all cpu_chain handlers. Tested on x86-64. All other archs are untested. Especially on sparc, I'm not sure if I got it right. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clocksource, acpi_pm.c: check for monotonicity clocksource, acpi_pm.c: use proper read function also in errata mode ntp: fix calculation of the next jiffie to trigger RTC sync x86: HPET: read back compare register before reading counter x86: HPET fix moronic 32/64bit thinko clockevents: broadcast fixup possible waiters HPET: make minimum reprogramming delta useful clockevents: prevent endless loop lockup clockevents: prevent multiple init/shutdown clockevents: enforce reprogram in oneshot setup clockevents: prevent endless loop in periodic broadcast handler clockevents: prevent clockevent event_handler ending up handler_noop
2008-09-06Merge branch 'sched/cpuset' into sched/urgentIngo Molnar
2008-09-06sched: arch_reinit_sched_domains() must destroy domains to force rebuildMax Krasnyansky
What I realized recently is that calling rebuild_sched_domains() in arch_reinit_sched_domains() by itself is not enough when cpusets are enabled. partition_sched_domains() code is trying to avoid unnecessary domain rebuilds and will not actually rebuild anything if new domain masks match the old ones. What this means is that doing echo 1 > /sys/devices/system/cpu/sched_mc_power_savings on a system with cpusets enabled will not take affect untill something changes in the cpuset setup (ie new sets created or deleted). This patch fixes restore correct behaviour where domains must be rebuilt in order to enable MC powersaving flags. Test on quad-core Core2 box with both CONFIG_CPUSETS and !CONFIG_CPUSETS. Also tested on dual-core Core2 laptop. Lockdep is happy and things are working as expected. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Tested-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06kernel/cpu.c: Move the CPU_DYING notifiersManfred Spraul
When a cpu is taken offline, the CPU_DYING notifiers are called on the dying cpu. According to <linux/notifiers.h>, the cpu should be "not running any task, not handling interrupts, soon dead". For the current implementation, this is not true: - __cpu_disable can fail. If it fails, then the cpu will remain alive and happy. - At least on x86, __cpu_disable() briefly enables the local interrupts to handle any outstanding interrupts. What about moving CPU_DYING down a few lines, behind the __cpu_disable() line? There are only two CPU_DYING handlers in the kernel right now: one in kvm, one in the scheduler. Both should work with the patch applied [and: I'm not sure if either one handles a failing __cpu_disable()] The patch survives simple offlining a cpu. kvm untested due to lack of a test setup. Signed-off-By: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06sched: fix __load_balance_iterator() for cfq with only one taskGautham R Shenoy
The __load_balance_iterator() returns a NULL when there's only one sched_entity which is a task. It is caused by the following code-path. /* Skip over entities that are not tasks */ do { se = list_entry(next, struct sched_entity, group_node); next = next->next; } while (next != &cfs_rq->tasks && !entity_is_task(se)); if (next == &cfs_rq->tasks) return NULL; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This will return NULL even when se is a task. As a side-effect, there was a regression in sched_mc behavior since 2.6.25, since iter_move_one_task() when it calls load_balance_start_fair(), would not get any tasks to move! Fix this by checking if the last entity was a task or not. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06Merge branch 'linus' into sched/develIngo Molnar
2008-09-06ntp: fix calculation of the next jiffie to trigger RTC syncMaciej W. Rozycki
We have a bug in the calculation of the next jiffie to trigger the RTC synchronisation. The aim here is to run sync_cmos_clock() as close as possible to the middle of a second. Which means we want this function to be called less than or equal to half a jiffie away from when now.tv_nsec equals 5e8 (500000000). If this is not the case for a given call to the function, for this purpose instead of updating the RTC we calculate the offset in nanoseconds to the next point in time where now.tv_nsec will be equal 5e8. The calculated offset is then converted to jiffies as these are the unit used by the timer. Hovewer timespec_to_jiffies() used here uses a ceil()-type rounding mode, where the resulting value is rounded up. As a result the range of now.tv_nsec when the timer will trigger is from 5e8 to 5e8 + TICK_NSEC rather than the desired 5e8 - TICK_NSEC / 2 to 5e8 + TICK_NSEC / 2. As a result if for example sync_cmos_clock() happens to be called at the time when now.tv_nsec is between 5e8 + TICK_NSEC / 2 and 5e8 to 5e8 + TICK_NSEC, it will simply be rescheduled HZ jiffies later, falling in the same range of now.tv_nsec again. Similarly for cases offsetted by an integer multiple of TICK_NSEC. This change addresses the problem by subtracting TICK_NSEC / 2 from the nanosecond offset to the next point in time where now.tv_nsec will be equal 5e8, effectively shifting the following rounding in timespec_to_jiffies() so that it produces a rounded-to-nearest result. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06sched: compilation fix with gcc 3.4.6Krzysztof Helt
I found that 2.6.27-rc5-mm1 does not compile with gcc 3.4.6. The error is: CC kernel/sched.o kernel/sched.c: In function `start_rt_bandwidth': kernel/sched.c:208: sorry, unimplemented: inlining failed in call to 'rt_bandwidth_enabled': function body not available kernel/sched.c:214: sorry, unimplemented: called from here make[1]: *** [kernel/sched.o] Error 1 make: *** [kernel] Error 2 It seems that the gcc 3.4.6 requires full inline definition before first usage. The patch below fixes the compilation problem. Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> (if needed> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06clockevents: broadcast fixup possible waitersThomas Gleixner
Until the C1E patches arrived there where no users of periodic broadcast before switching to oneshot mode. Now we need to trigger a possible waiter for a periodic broadcast when switching to oneshot mode. Otherwise we can starve them for ever. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-09-05sched: fix process time monotonicityBalbir Singh
Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05sched_clock: fix NOHZ interactionPeter Zijlstra
If HLT stops the TSC, we'll fail to account idle time, thereby inflating the actual process times. Fix this by re-calibrating the clock against GTOD when leaving nohz mode. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05clockevents: prevent endless loop lockupThomas Gleixner
The C1E/HPET bug reports on AMDX2/RS690 systems where tracked down to a too small value of the HPET minumum delta for programming an event. The clockevents code needs to enforce an interrupt event on the clock event device in some cases. The enforcement code was stupid and naive, as it just added the minimum delta to the current time and tried to reprogram the device. When the minimum delta is too small, then this loops forever. Add a sanity check. Allow reprogramming to fail 3 times, then print a warning and double the minimum delta value to make sure, that this does not happen again. Use the same function for both tick-oneshot and tick-broadcast code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05clockevents: prevent multiple init/shutdownThomas Gleixner
While chasing the C1E/HPET bugreports I went through the clock events code inch by inch and found that the broadcast device can be initialized and shutdown multiple times. Multiple shutdowns are not critical, but useless waste of time. Multiple initializations are simply broken. Another CPU might have the device in use already after the first initialization and the second init could just render it unusable again. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05clockevents: enforce reprogram in oneshot setupThomas Gleixner
In tick_oneshot_setup we program the device to the given next_event, but we do not check the return value. We need to make sure that the device is programmed enforced so the interrupt handler engine starts working. Split out the reprogramming function from tick_program_event() and call it with the device, which was handed in to tick_setup_oneshot(). Set the force argument, so the devices is firing an interrupt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05clockevents: prevent endless loop in periodic broadcast handlerThomas Gleixner
The reprogramming of the periodic broadcast handler was broken, when the first programming returned -ETIME. The clockevents code stores the new expiry value in the clock events device next_event field only when the programming time has not been elapsed yet. The loop in question calculates the new expiry value from the next_event value and therefor never increases. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05clockevents: prevent clockevent event_handler ending up handler_noopVenkatesh Pallipadi
There is a ordering related problem with clockevents code, due to which clockevents_register_device() called after tickless/highres switch will not work. The new clockevent ends up with clockevents_handle_noop as event handler, resulting in no timer activity. The problematic path seems to be * old device already has hrtimer_interrupt as the event_handler * new clockevent device registers with a higher rating * tick_check_new_device() is called * clockevents_exchange_device() gets called * old->event_handler is set to clockevents_handle_noop * tick_setup_device() is called for the new device * which sets new->event_handler using the old->event_handler which is noop. Change the ordering so that new device inherits the proper handler. This does not have any issue in normal case as most likely all the clockevent devices are setup before the highres switch. But, can potentially be affecting some corner case where HPET force detect happens after the highres switch. This was a problem with HPET in MSI mode code that we have been experimenting with. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05Merge branch 'x86/core' into x86/unify-cpu-detectIngo Molnar
2008-09-04Merge branch 'core/resources' into x86/coreIngo Molnar
2008-09-04IO resources: add reserve_region_with_split()Yinghai Lu
add reserve_region_with_split() to not lose e820 reserved entries if they overlap with existing IO regions: with test case by extend 0xe0000000 - 0xeffffff to 0xdd800000 - we get: e0000000-efffffff : PCI MMCONFIG 0 e0000000-efffffff : reserved and in /proc/iomem we get: found conflict for reserved [dd800000, efffffff], try to reserve with split __reserve_region_with_split: (PCI Bus #80) [dd000000, ddffffff], res: (reserved) [dd800000, efffffff] __reserve_region_with_split: (PCI Bus #00) [de000000, dfffffff], res: (reserved) [de000000, efffffff] initcall pci_subsys_init+0x0/0x121 returned 0 after 381 msecs in dmesg various fixes and improvements suggested by Linus. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-04forgotten refcount on sysctl root tableAl Viro
We should've set refcount on the root sysctl table; otherwise we'll blow up the first time we get down to zero dynamically registered sysctl tables. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-04Merge branch 'linus' into x86/coreH. Peter Anvin
2008-09-04Merge branch 'x86/cpu' into x86/coreH. Peter Anvin
Conflicts: arch/x86/kernel/cpu/feature_names.c include/asm-x86/cpufeature.h
2008-09-02pm_qos_requirement might sleepJohn Kacur
Make PM_QOS and CPU_IDLE play nicer when run with the RT-Preempt kernel. The purpose of the patch is to remove the spin_lock around the read in the function pm_qos_requirement - since spinlocks can sleep in -rt and this function is called from idle. CPU_IDLE polls the target_value's of some of the pm_qos parameters from the idle loop causing sleeping locking warnings. Changing the target_value to an atomic avoids this issue. Remove the spinlock in pm_qos_requirement by making target_value an atomic type. Signed-off-by: mark gross <mgross@linux.intel.com> Signed-off-by: John Kacur <jkacur@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exitsOleg Nesterov
We don't change pid_ns->child_reaper when the main thread of the subnamespace init exits. As Robert Rex <robert.rex@exasol.com> pointed out this is wrong. Yes, the re-parenting itself works correctly, but if the reparented task exits it needs ->parent->nsproxy->pid_ns in do_notify_parent(), and if the main thread is zombie its ->nsproxy was already cleared by exit_task_namespaces(). Introduce the new function, find_new_reaper(), which finds the new ->parent for the re-parenting and changes ->child_reaper if needed. Kill the now unneeded exit_child_reaper(). Also move the changing of ->child_reaper from zap_pid_ns_processes() to find_new_reaper(), this consolidates the games with ->child_reaper and makes it stable under tasklist_lock. Addresses http://bugzilla.kernel.org/show_bug.cgi?id=11391 Reported-by: Robert Rex <robert.rex@exasol.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02pid_ns: zap_pid_ns_processes: fix the ->child_reaper changingOleg Nesterov
zap_pid_ns_processes() sets pid_ns->child_reaper = NULL, this is wrong. Yes, we have already killed all tasks in this namespace, and sys_wait4() doesn't see any child. But this doesn't mean ->children list is empty, we may have EXIT_DEAD tasks which are not visible to do_wait(). In that case the subsequent forget_original_parent() will crash the kernel because it will try to re-parent these tasks to the NULL reaper. Even if there are no childs, it is not good that forget_original_parent() uses reaper == NULL. Change the code to set ->child_reaper = init_pid_ns.child_reaper instead. We could use pid_ns->parent->child_reaper as well, I think this does not really matter. These EXIT_DEAD tasks are not visible to the new ->parent after re-parenting, they will silently do release_task() eventually. Note that we must change ->child_reaper, otherwise forget_original_parent() will use reaper == father, and in that case we will hit the (correct) BUG_ON(!list_empty(&father->children)). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02Merge branch 'audit.b57' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b57' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: [PATCH] audit: Moved variable declaration to beginning of function
2008-09-02softlockup: minor cleanup, don't check task->state twiceOleg Nesterov
The recent commit 16d9679f33caf7e683471647d1472bfe133d858 changed check_hung_task() to filter out the TASK_KILLABLE tasks. We can move this check to the caller which has to test t->state anyway. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02kernel/resource.c: fix new kernel-doc warningRandy Dunlap
Fix kernel-doc warning for new function: Warning(linux-2.6.27-rc5-git2//kernel/resource.c:448): No description found for parameter 'root' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-01[PATCH] audit: Moved variable declaration to beginning of functionCordelia
got rid of compilation warning: ISO C90 forbids mixed declarations and code Signed-off-by: Cordelia Sam <cordesam@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-29Resource handling: add 'insert_resource_expand_to_fit()' functionLinus Torvalds
Not used anywhere yet, but this complements the existing plain 'insert_resource()' functionality with a version that can expand the resource we are adding in order to fix up any conflicts it has with existing resources. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-29Don't trigger softlockup detector on network fs blocked tasksAndi Kleen
Pulling the ethernet cable on a 2.6.27-rc system with NFS mounts currently leads to an ongoing flood of soft lockup detector backtraces for all tasks blocked on the NFS mounts when the hickup takes longer than 120s. I don't think NFS problems should be all that noisy. Luckily there's a reasonably easy way to distingush this case. Don't report task softlockup warnings for tasks in TASK_KILLABLE state, which is used by the network file systems. I believe this patch is a 2.6.27 candidate. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-28Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: exit signals: use of uninitialized field notify_count lockdep: fix invalid list_del_rcu in zap_class lockstat: repair erronous contention statistics lockstat: fix numerical output rounding error
2008-08-28Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: rt-bandwidth accounting fix sched: fix sched_rt_rq_enqueue() resched idle
2008-08-28Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: update defconfigs x86: msr: fix bogus return values from rdmsr_safe/wrmsr_safe x86: cpuid: correct return value on partial operations x86: msr: correct return value on partial operations x86: cpuid: propagate error from smp_call_function_single() x86: msr: propagate errors from smp_call_function_single() smp: have smp_call_function_single() detect invalid CPUs