Steven Rostedt 6fa46fa526 sched: balance RT task resched only on runqueue ... Sripathi Kodi reported a crash in the -rt kernel: https://bugzilla.redhat.com/show_bug.cgi?id=435674 this is due to a place that can reschedule a task without holding the tasks runqueue lock. This was caused by the RT balancing code that pulls RT tasks to the current run queue and will reschedule the current task. There's a slight chance that the pulling of the RT tasks will release the current runqueue's lock and retake it (in the double_lock_balance). During this time that the runqueue is released, the current task can migrate to another runqueue. In the prio_changed_rt code, after the pull, if the current task is of lesser priority than one of the RT tasks pulled, resched_task is called on the current task. If the current task had migrated in that small window, resched_task will be called without holding the runqueue lock for the runqueue that the task is on. This race condition also exists in the mainline kernel and this patch adds a check to make sure the task hasn't migrated before calling resched_task. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Tested-by: Sripathi Kodi <sripathik@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2008-03-07 16:43:00 +01:00
..
irq	genirq: do not leave interupts enabled on free_irq	2008-02-19 10:43:58 +01:00
power	freezer vs stopped or traced	2008-03-04 07:59:54 -08:00
time	rcu: add support for dynamic ticks and preempt rcu	2008-02-29 18:46:50 +01:00
.gitignore	Update kernel/.gitignore with new auto-generated files	2008-02-09 23:27:01 -08:00
acct.c	acct: real_parent ppid	2008-01-07 14:55:37 -08:00
audit_tree.c	Introduce path_put()	2008-02-14 21:13:33 -08:00
audit.c	[PATCH] drop EOE records from printk	2008-03-01 07:16:06 -05:00
audit.h	[PATCH] audit: watching subtrees	2007-10-21 02:37:45 -04:00
auditfilter.c	Introduce path_put()	2008-02-14 21:13:33 -08:00
auditsc.c	[PATCH] Audit: Fix the format type for size_t variables	2008-03-01 07:16:06 -05:00
backtracetest.c	x86: add a simple backtrace test module	2008-01-30 13:33:08 +01:00
capability.c	Add 64-bit capability support to the kernel	2008-02-05 09:44:20 -08:00
cgroup_debug.c	Task Control Groups: simple task cgroup debug info subsystem	2007-10-19 11:53:36 -07:00
cgroup.c	cgroup: fix default notify_on_release setting	2008-03-04 16:35:09 -08:00
compat.c	hrtimer: don't modify restart_block->fn in restart functions	2008-02-10 10:48:03 +01:00
configs.c	use simple_read_from_buffer in kernel/	2007-05-09 12:30:49 -07:00
cpu.c	cpu: fix section mismatch warnings for enable_nonboot_cpus	2008-02-08 09:22:41 -08:00
cpuset.c	cpusets: fix obsolete comment	2008-03-05 17:53:33 -08:00
delayacct.c	Add scaled time to taskstats based process accounting	2007-10-18 14:37:28 -07:00
dma.c	whitespace fixes: DMA channel allocator	2007-10-18 14:37:24 -07:00
exec_domain.c	whitespace fixes: execution domains	2007-10-18 14:37:26 -07:00
exit.c	exit_notify: fix kill_orphaned_pgrp() usage with mt exit	2008-03-03 14:53:16 -08:00
extable.c	module: Don't report discarded init pages as kernel text.	2008-01-29 17:13:18 +11:00
fork.c	Use struct path in fs_struct	2008-02-14 21:13:33 -08:00
futex_compat.c	futex: runtime enable pi and robust functionality	2008-02-23 17:12:15 -08:00
futex.c	futex: runtime enable pi and robust functionality	2008-02-23 17:12:15 -08:00
hrtimer.c	hrtimer: catch expired CLOCK_REALTIME timers early	2008-02-14 22:08:30 +01:00
itimer.c	ITIMER_REAL: convert to use struct pid	2008-02-08 09:22:29 -08:00
kallsyms.c	remove support for un-needed _extratext section	2008-02-06 10:41:01 -08:00
Kconfig.hz	sched: high-res preemption tick	2008-01-25 21:08:29 +01:00
Kconfig.preempt	sched: remove the !PREEMPT_BKL code	2008-01-25 21:08:33 +01:00
kexec.c	vmcoreinfo: add "VMCOREINFO_" to all the call for vmcoreinfo_append_str()	2008-02-07 08:42:25 -08:00
kfifo.c	is_power_of_2: kernel/kfifo.c	2007-07-16 09:05:50 -07:00
kmod.c	Dont touch fs_struct in usermodehelper	2008-02-14 21:13:32 -08:00
kprobes.c	kprobes: fix a null pointer bug in register_kretprobe()	2008-03-04 16:35:19 -08:00
ksysfs.c	Kobject: convert remaining kobject_unregister() to kobject_put()	2008-01-24 20:40:40 -08:00
kthread.c	sched: fix, always create kernel threads with normal priority	2008-01-25 21:08:33 +01:00
latencytop.c	sched: latencytop support	2008-01-25 21:08:34 +01:00
lockdep_internals.h	[PATCH] lockdep: more chains	2006-12-07 08:39:43 -08:00
lockdep_proc.c	lockdep: Avoid /proc/lockdep & lock_stat infinite output	2007-10-11 22:11:11 +02:00
lockdep.c	Subject: lockdep: include all lock classes in all_lock_classes	2008-02-25 23:03:02 +01:00
Makefile	avoid overflows in kernel/time.c	2008-02-08 09:22:39 -08:00
marker.c	markers: don't risk NULL deref in marker	2008-03-04 16:35:14 -08:00
module.c	module: allow ndiswrapper to use GPL-only symbols	2008-03-04 20:29:40 -08:00
mutex-debug.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
mutex-debug.h	[PATCH] lockdep: better lock debugging	2006-07-03 15:27:01 -07:00
mutex.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
mutex.h	[PATCH] lockdep: prove mutex locking correctness	2006-07-03 15:27:04 -07:00
notifier.c	kernel/notifier.c should #include <linux/reboot.h>	2008-02-06 10:41:02 -08:00
ns_cgroup.c	cgroups: implement namespace tracking subsystem	2007-10-19 11:53:37 -07:00
nsproxy.c	namespaces: move the IPC namespace under IPC_NS option	2008-02-08 09:22:23 -08:00
panic.c	ACPI: Taint kernel on ACPI table override (format corrected)	2008-02-06 22:07:51 -05:00
params.c	Add new string functions strict_strto* and convert kernel params to use them	2008-02-08 09:22:41 -08:00
pid_namespace.c	namespaces: cleanup the code managed with PID_NS option	2008-02-08 09:22:23 -08:00
pid.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
pm_qos_params.c	pm qos infrastructure and interface	2008-02-05 09:44:22 -08:00
posix-cpu-timers.c	Use find_task_by_vpid in posix timers	2008-02-08 09:22:41 -08:00
posix-timers.c	hrtimer: check relative timeouts for overflow	2008-02-14 22:08:30 +01:00
printk.c	printk: fix possible printk overrun	2008-02-26 07:42:37 -08:00
profile.c	Nuke a duplicate include from profile.c	2008-02-08 09:22:34 -08:00
ptrace.c	ptrace_check_attach: remove unneeded ->signal != NULL check	2008-02-08 09:22:26 -08:00
rcuclassic.c	Preempt-RCU: implementation	2008-01-25 21:08:24 +01:00
rcupdate.c	rcupdate: fix comment	2008-02-13 16:21:18 -08:00
rcupreempt_trace.c	Preempt-RCU: implementation	2008-01-25 21:08:24 +01:00
rcupreempt.c	rcupreempt: remove never-migrates assumption from rcu_process_callbacks()	2008-02-29 20:21:13 +01:00
rcutorture.c	cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus()	2008-01-25 21:08:02 +01:00
relay.c	relay: nopage	2008-02-06 10:41:07 -08:00
res_counter.c	Memory Resource Controller use strstrip while parsing arguments	2008-03-04 16:35:09 -08:00
resource.c	[POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc	2008-02-08 19:52:48 +11:00
rtmutex_common.h	Don't operate with pid_t in rtmutex tester	2008-02-08 09:22:41 -08:00
rtmutex-debug.c	Don't operate with pid_t in rtmutex tester	2008-02-08 09:22:41 -08:00
rtmutex-debug.h	[PATCH] lockdep: better lock debugging	2006-07-03 15:27:01 -07:00
rtmutex-tester.c	Driver core: change sysdev classes to use dynamic kobject names	2008-01-24 20:40:40 -08:00
rtmutex.c	hrtimer: more hrtimer_init_sleeper() fallout.	2008-02-13 15:45:36 +01:00
rtmutex.h	[PATCH] lockdep: better lock debugging	2006-07-03 15:27:01 -07:00
rwsem.c	sched: mark rwsem functions as __sched for wchan/profiling	2007-12-18 15:21:13 +01:00
sched_debug.c	sched: keep total / count stats in addition to the max for	2008-01-25 21:08:35 +01:00
sched_fair.c	sched: retain vruntime	2008-03-07 16:42:59 +01:00
sched_idletask.c	sched: high-res preemption tick	2008-01-25 21:08:29 +01:00
sched_rt.c	sched: balance RT task resched only on runqueue	2008-03-07 16:43:00 +01:00
sched_stats.h	sched: clean up kernel/sched_stat.h	2007-11-28 15:52:56 +01:00
sched.c	sched: retain vruntime	2008-03-07 16:42:59 +01:00
seccomp.c	make seccomp zerocost in schedule	2007-07-16 09:05:50 -07:00
signal.c	freezer vs stopped or traced	2008-03-04 07:59:54 -08:00
softirq.c	rcu: add support for dynamic ticks and preempt rcu	2008-02-29 18:46:50 +01:00
softlockup.c	softlockup: fix task state setting	2008-02-29 18:46:53 +01:00
spinlock.c	spinlock: lockbreak cleanup	2008-01-30 13:31:20 +01:00
srcu.c	make srcu_readers_active() static	2008-02-06 10:41:02 -08:00
stacktrace.c	[PATCH] lockdep: stacktrace subsystem, core	2006-07-03 15:27:02 -07:00
stop_machine.c	stopmachine: semaphore to mutex	2008-02-06 10:41:08 -08:00
sys_ni.c	timerfd: new timerfd API	2008-02-05 09:44:07 -08:00
sys.c	Pidns: make full use of xxx_vnr() calls	2008-02-08 09:22:29 -08:00
sysctl_check.c	constify tables in kernel/sysctl_check.c	2008-02-08 09:22:31 -08:00
sysctl.c	sched: revert load_balance_monitor() changes	2008-03-04 17:54:06 +01:00
taskstats.c	kernel/taskstats.c: fix bogus nlmsg_free()	2007-11-14 18:45:44 -08:00
test_kprobes.c	kprobes: kretprobe user entry-handler	2008-02-06 10:41:11 -08:00
time.c	avoid overflows in kernel/time.c	2008-02-08 09:22:39 -08:00
timeconst.pl	timeconst.pl: correct reversal of USEC_TO_HZ and HZ_TO_USEC	2008-02-12 14:29:26 -08:00
timer.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
tsacct.c	Add scaled time to taskstats based process accounting	2007-10-18 14:37:28 -07:00
uid16.c	header cleaning: don't include smp_lock.h when not used	2007-05-08 11:15:07 -07:00
user_namespace.c	namespaces: cleanup the code managed with the USER_NS option	2008-02-08 09:22:23 -08:00
user.c	sched: rt-group: make rt groups scheduling configurable	2008-02-13 15:45:40 +01:00
utsname_sysctl.c	Isolate the UTS namespace's domainname and hostname back	2007-11-29 09:24:53 -08:00
utsname.c	Fix UTS corruption during clone(CLONE_NEWUTS)	2007-09-19 11:24:17 -07:00
wait.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
workqueue.c	workqueue: make delayed_work_timer_fn() static	2008-02-08 09:22:37 -08:00