Frederic Weisbecker 416eb33cd6 rcu: Fix early call to rcu_idle_enter() ...

On the irq exit path, tick_nohz_irq_exit()
may raise a softirq, which action leads to the wake up
path and select_task_rq_fair() that makes use of rcu
to iterate the domains.

This is an illegal use of RCU because we may be in RCU
extended quiescent state if we interrupted an RCU-idle
window in the idle loop:

[  132.978883] ===============================
[  132.978883] [ INFO: suspicious RCU usage. ]
[  132.978883] -------------------------------
[  132.978883] kernel/sched_fair.c:1707 suspicious rcu_dereference_check() usage!
[  132.978883]
[  132.978883] other info that might help us debug this:
[  132.978883]
[  132.978883]
[  132.978883] rcu_scheduler_active = 1, debug_locks = 0
[  132.978883] RCU used illegally from extended quiescent state!
[  132.978883] 2 locks held by swapper/0:
[  132.978883]  #0:  (&p->pi_lock){-.-.-.}, at: [<ffffffff8105a729>] try_to_wake_up+0x39/0x2f0
[  132.978883]  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff8105556a>] select_task_rq_fair+0x6a/0xec0
[  132.978883]
[  132.978883] stack backtrace:
[  132.978883] Pid: 0, comm: swapper Tainted: G        W   3.0.0+ #178
[  132.978883] Call Trace:
[  132.978883]  <IRQ>  [<ffffffff810a01f6>] lockdep_rcu_suspicious+0xe6/0x100
[  132.978883]  [<ffffffff81055c49>] select_task_rq_fair+0x749/0xec0
[  132.978883]  [<ffffffff8105556a>] ? select_task_rq_fair+0x6a/0xec0
[  132.978883]  [<ffffffff812fe494>] ? do_raw_spin_lock+0x54/0x150
[  132.978883]  [<ffffffff810a1f2d>] ? trace_hardirqs_on+0xd/0x10
[  132.978883]  [<ffffffff8105a7c3>] try_to_wake_up+0xd3/0x2f0
[  132.978883]  [<ffffffff81094f98>] ? ktime_get+0x68/0xf0
[  132.978883]  [<ffffffff8105aa35>] wake_up_process+0x15/0x20
[  132.978883]  [<ffffffff81069dd5>] raise_softirq_irqoff+0x65/0x110
[  132.978883]  [<ffffffff8108eb65>] __hrtimer_start_range_ns+0x415/0x5a0
[  132.978883]  [<ffffffff812fe3ee>] ? do_raw_spin_unlock+0x5e/0xb0
[  132.978883]  [<ffffffff8108ed08>] hrtimer_start+0x18/0x20
[  132.978883]  [<ffffffff8109c9c3>] tick_nohz_stop_sched_tick+0x393/0x450
[  132.978883]  [<ffffffff810694f2>] irq_exit+0xd2/0x100
[  132.978883]  [<ffffffff81829e96>] do_IRQ+0x66/0xe0
[  132.978883]  [<ffffffff81820d53>] common_interrupt+0x13/0x13
[  132.978883]  <EOI>  [<ffffffff8103434b>] ? native_safe_halt+0xb/0x10
[  132.978883]  [<ffffffff810a1f2d>] ? trace_hardirqs_on+0xd/0x10
[  132.978883]  [<ffffffff810144ea>] default_idle+0xba/0x370
[  132.978883]  [<ffffffff810147fe>] amd_e400_idle+0x5e/0x130
[  132.978883]  [<ffffffff8100a9f6>] cpu_idle+0xb6/0x120
[  132.978883]  [<ffffffff817f217f>] rest_init+0xef/0x150
[  132.978883]  [<ffffffff817f20e2>] ? rest_init+0x52/0x150
[  132.978883]  [<ffffffff81ed9cf3>] start_kernel+0x3da/0x3e5
[  132.978883]  [<ffffffff81ed9346>] x86_64_start_reservations+0x131/0x135
[  132.978883]  [<ffffffff81ed944d>] x86_64_start_kernel+0x103/0x112

Fix this by calling rcu_idle_enter() after tick_nohz_irq_exit().

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

2011-12-11 10:31:38 -08:00

..

debug

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

events

perf: Do no try to schedule task events if there are none

2011-12-07 16:31:22 +01:00

gcov

gcov: disable CONSTRUCTORS for UML

2011-07-26 16:49:45 -07:00

irq

genirq: Fix race condition when stopping the irq thread

2011-12-02 11:54:24 +01:00

power

PM / Hibernate: Do not leak memory in error/test code paths

2011-11-23 21:03:38 +01:00

time

nohz: Allow rcu extended quiescent state handling seperately from tick stop

2011-12-11 10:31:36 -08:00

trace

trace: Allow ftrace_dump() to be called from modules

2011-12-11 10:31:25 -08:00

.gitignore

…

acct.c

pass a struct path to vfs_statfs

2010-08-09 16:48:42 -04:00

async.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

audit_tree.c

audit_tree,rcu: Convert call_rcu(__put_tree) to kfree_rcu()

2011-07-20 14:10:11 -07:00

audit_watch.c

kill path_lookup()

2011-03-14 09:15:23 -04:00

audit.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

audit.h

audit: make functions static

2010-10-30 01:42:19 -04:00

auditfilter.c

netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms

2011-03-03 10:55:40 -08:00

auditsc.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

backtracetest.c

…

bounds.c

memcg: remove direct page_cgroup-to-page pointer

2011-03-23 19:46:28 -07:00

capability.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

cgroup_freezer.c

cgroup_freezer: fix freezing groups with stopped tasks

2011-11-24 11:58:22 -08:00

cgroup.c

memcg: replace ss->id_lock with a rwlock

2011-11-02 16:07:03 -07:00

compat.c

kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure

2011-10-31 19:30:05 -04:00

configs.c

kernel/configs.c: include MODULE_*() when CONFIG_IKCONFIG_PROC=n

2011-07-25 20:57:15 -07:00

cpu_pm.c

cpu_pm: call notifiers during suspend

2011-09-23 12:05:29 +05:30

cpu.c

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

cpuset.c

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

crash_dump.c

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

cred.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

delayacct.c

KVM: Steal time implementation

2011-07-14 12:59:14 +03:00

dma.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

elfcore.c

…

exec_domain.c

sys_personality: remove the bogus checks in sys_personality()->__set_personality() path

2010-08-09 20:45:05 -07:00

exit.c

oom: remove oom_disable_count

2011-10-31 17:30:45 -07:00

extable.c

extable, core_kernel_data(): Make sure all archs define _sdata

2011-05-20 08:56:56 +02:00

fork.c

writeback: remove vm_dirties and task->dirties

2011-11-17 20:49:06 +08:00

freezer.c

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

futex_compat.c

userns: user namespaces: convert several capable() calls

2011-03-23 19:47:08 -07:00

futex.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

groups.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

hrtimer.c

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2011-11-28 08:43:52 -08:00

hung_task.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

irq_work.c

kernel: fix two implicit header assumptions in irq_work.c

2011-10-31 09:20:12 -04:00

itimer.c

…

jump_label.c

jump_label: jump_label_inc may return before the code is patched

2011-12-05 13:28:46 -05:00

kallsyms.c

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-03-25 17:52:22 -07:00

Kconfig.freezer

…

Kconfig.hz

…

Kconfig.locks

arch:Kconfig.locks Remove unused config option.

2011-04-10 17:01:05 +02:00

Kconfig.preempt

sched: Isolate preempt counting in its own config option

2011-06-10 15:15:40 +02:00

kexec.c

[S390] kdump: Add infrastructure for unmapping crashkernel memory

2011-10-30 15:16:42 +01:00

kfifo.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

kmod.c

kmod: prevent kmod_loop_msg overflow in __request_module()

2011-10-26 13:10:39 +10:30

kprobes.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

ksysfs.c

kernel: ksysfs.c is implicitly using stat.h

2011-10-31 09:20:13 -04:00

kthread.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

latencytop.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

lockdep_internals.h

…

lockdep_proc.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

lockdep_states.h

…

lockdep.c

rcu: Inform the user about extended quiescent state on PROVE_RCU warning

2011-12-11 10:31:30 -08:00

Makefile

Merge branch 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm

2011-10-28 12:02:27 -07:00

module.c

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

mutex-debug.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

mutex-debug.h

mutex: Use p->on_cpu for the adaptive spin

2011-04-14 08:52:33 +02:00

mutex.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

mutex.h

mutex: Use p->on_cpu for the adaptive spin

2011-04-14 08:52:33 +02:00

notifier.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

nsproxy.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

padata.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

panic.c

module,bug: Add TAINT_OOT_MODULE flag for modules not built in-tree

2011-11-07 07:54:42 +10:30

params.c

kernel: params.c needs module.h not moduleparam.h

2011-10-31 09:20:13 -04:00

pid_namespace.c

pidns: call pid_ns_prepare_proc() from create_pid_namespace()

2011-03-23 19:46:58 -07:00

pid.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

posix-cpu-timers.c

Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2011-10-26 16:17:32 +02:00

posix-timers.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

printk.c

printk: avoid double lock acquire

2011-12-09 07:50:28 -08:00

profile.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

ptrace.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

range.c

range: fix bogus misuse of module.h to get printk()

2011-10-31 09:20:11 -04:00

rcu.h

rcu: Add grace-period, quiescent-state, and call_rcu trace events

2011-09-28 21:38:21 -07:00

rcupdate.c

rcu: Detect illegal rcu dereference in extended quiescent state

2011-12-11 10:31:30 -08:00

rcutiny_plugin.h

kernel: fix up module header handling in rcutiny files

2011-10-31 09:20:13 -04:00

rcutiny.c

rcu: Detect illegal rcu dereference in extended quiescent state

2011-12-11 10:31:30 -08:00

rcutorture.c

rcu: Add failure tracing to rcutorture

2011-12-11 10:31:26 -08:00

rcutree_plugin.h

rcu: Remove redundant return from rcu_report_exp_rnp()

2011-12-11 10:31:29 -08:00

rcutree_trace.c

rcu: Track idleness independent of idle tasks

2011-12-11 10:31:24 -08:00

rcutree.c

rcu: Detect illegal rcu dereference in extended quiescent state

2011-12-11 10:31:30 -08:00

rcutree.h

rcu: Omit self-awaken when setting up expedited grace period

2011-12-11 10:31:28 -08:00

relay.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

res_counter.c

memcg: res_counter_read_u64(): fix potential races on 32-bit machines

2011-03-23 19:46:22 -07:00

resource.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

rtmutex_common.h

rtmutex: Simplify PI algorithm and make highest prio task get lock

2011-01-27 21:13:51 -05:00

rtmutex-debug.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

rtmutex-debug.h

…

rtmutex-tester.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

rtmutex.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

rtmutex.h

…

rwsem.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

sched_autogroup.c

Fix common misspellings

2011-03-31 11:26:23 -03:00

sched_autogroup.h

sched: Skip autogroup when looking for all rt sched groups

2011-07-01 10:39:08 +02:00

sched_clock.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

sched_cpupri.c

sched/cpupri: Remove cpupri->pri_active

2011-08-14 12:01:11 +02:00

sched_cpupri.h

sched/cpupri: Remove cpupri->pri_active

2011-08-14 12:01:11 +02:00

sched_debug.c

sched: Get rid of lock_depth

2011-04-24 13:18:38 +02:00

sched_fair.c

sched: Fix buglet in return_cfs_rq_runtime()

2011-11-16 08:43:45 +01:00

sched_features.h

sched, rt: Provide means of disabling cross-cpu bandwidth sharing

2011-11-14 12:50:40 +01:00

sched_idletask.c

sched: Drop the rq argument to sched_class::select_task_rq()

2011-04-14 08:52:36 +02:00

sched_rt.c

sched, rt: Provide means of disabling cross-cpu bandwidth sharing

2011-11-14 12:50:40 +01:00

sched_stats.h

locking, sched: Annotate thread_group_cputimer as raw

2011-09-13 11:11:55 +02:00

sched_stoptask.c

sched: Implement hierarchical task accounting for SCHED_OTHER

2011-08-14 12:01:13 +02:00

sched.c

sched: Set the command name of the idle tasks in SMP kernels

2011-11-14 12:50:43 +01:00

seccomp.c

…

semaphore.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

signal.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

smp.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

softirq.c

rcu: Fix early call to rcu_idle_enter()

2011-12-11 10:31:38 -08:00

spinlock.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

srcu.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

stacktrace.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

stop_machine.c

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

sys_ni.c

Cross Memory Attach

2011-10-31 17:30:44 -07:00

sys.c

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

sysctl_binary.c

ipv4: NET_IPV4_ROUTE_GC_INTERVAL removal

2011-10-03 14:13:01 -04:00

sysctl_check.c

xfs: remove subdirectories

2011-08-12 16:21:35 -05:00

sysctl.c

Merge branch 'akpm' (Andrew's incoming)

2011-10-31 17:46:07 -07:00

taskstats.c

Make TASKSTATS require root access

2011-09-19 17:04:37 -07:00

test_kprobes.c

kprobes: Fix selftest to clear flags field for reusing probes

2010-10-14 08:55:27 +02:00

time.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

timeconst.pl

…

timer.c

sys_getppid: add missing rcu_dereference

2011-12-09 07:50:29 -08:00

tracepoint.c

Tracepoint: Dissociate from module mutex

2011-08-10 20:38:14 -04:00

tsacct.c

Make taskstats round statistics down to nearest 1k bytes/events

2011-09-19 17:10:57 -07:00

uid16.c

userns: user namespaces: convert several capable() calls

2011-03-23 19:47:08 -07:00

up.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

user_namespace.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

user-return-notifier.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

user.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

utsname_sysctl.c

Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2011-11-06 19:44:47 -08:00

utsname.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

wait.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00

watchdog.c

watchdog: move watchdog_*_all_cpus under CONFIG_SYSCTL

2011-10-31 17:30:53 -07:00

workqueue_sched.h

workqueue: implement concurrency managed dynamic worker pool

2010-06-29 10:07:14 +02:00

workqueue.c

kernel: Map most files to use export.h instead of module.h

2011-10-31 09:20:12 -04:00