Peter Zijlstra 058ebd0eba perf: Fix perf_lock_task_context() vs RCU ... Jiri managed to trigger this warning: [] ====================================================== [] [ INFO: possible circular locking dependency detected ] [] 3.10.0+ #228 Tainted: G W [] ------------------------------------------------------- [] p/6613 is trying to acquire lock: [] (rcu_node_0){..-...}, at: [<ffffffff810ca797>] rcu_read_unlock_special+0xa7/0x250 [] [] but task is already holding lock: [] (&ctx->lock){-.-...}, at: [<ffffffff810f2879>] perf_lock_task_context+0xd9/0x2c0 [] [] which lock already depends on the new lock. [] [] the existing dependency chain (in reverse order) is: [] [] -> #4 (&ctx->lock){-.-...}: [] -> #3 (&rq->lock){-.-.-.}: [] -> #2 (&p->pi_lock){-.-.-.}: [] -> #1 (&rnp->nocb_gp_wq[1]){......}: [] -> #0 (rcu_node_0){..-...}: Paul was quick to explain that due to preemptible RCU we cannot call rcu_read_unlock() while holding scheduler (or nested) locks when part of the read side critical section was preemptible. Therefore solve it by making the entire RCU read side non-preemptible. Also pull out the retry from under the non-preempt to play nice with RT. Reported-by: Jiri Olsa <jolsa@redhat.com> Helped-out-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>		2013-07-12 11:11:09 +02:00
..
cpu	idle: Enable interrupts in the weak arch_cpu_idle() implementation	2013-06-14 23:01:05 +02:00
debug	kgdb/sysrq: fix inconstistent help message of sysrq key	2013-04-30 17:04:10 -07:00
events	perf: Fix perf_lock_task_context() vs RCU	2013-07-12 11:11:09 +02:00
gcov	kernel/gcov: remove depends on CONFIG_EXPERIMENTAL	2013-01-11 11:39:33 -08:00
irq	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-07-02 16:14:35 -07:00
power	Finally eradicate CONFIG_HOTPLUG	2013-06-03 14:20:18 -07:00
sched	Linux 3.10	2013-07-01 11:18:53 +02:00
time	tick: Fix tick_broadcast_pending_mask not cleared	2013-06-21 13:10:34 +02:00
trace	tracing: Fix outputting formats of x86-tsc and counter when use trace_clock	2013-06-11 13:58:46 -04:00
.gitignore	kernel/hz.bc: ignore.	2013-04-22 07:09:06 -07:00
acct.c	fs: Fix hang with BSD accounting on frozen filesystem	2013-05-04 14:57:58 -04:00
async.c	async: rename and redefine async_func_ptr	2013-03-12 13:59:14 -07:00
audit_tree.c	kernel/audit_tree.c:audit_add_tree_rule(): protect `rule' from kill_rules()	2013-06-12 16:29:46 -07:00
audit_watch.c	audit: catch possible NULL audit buffers	2013-01-11 14:54:55 -08:00
audit.c	audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE	2013-06-12 16:29:45 -07:00
audit.h	Merge git://git.infradead.org/users/eparis/audit	2013-05-11 14:29:11 -07:00
auditfilter.c	auditfilter.c: fix kernel-doc warnings	2013-05-24 16:22:52 -07:00
auditsc.c	audit: Make testing for a valid loginuid explicit.	2013-05-07 22:27:15 -04:00
backtracetest.c
bounds.c
capability.c	Add file_ns_capable() helper function for open-time capability checking	2013-04-14 10:06:31 -07:00
cgroup_freezer.c
cgroup.c	cgroup: warn about mismatching options of a new mount of an existing hierarchy	2013-05-29 07:59:39 +09:00
compat.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-05-01 07:21:43 -07:00
configs.c	proc: Supply PDE attribute setting accessor functions	2013-05-01 17:29:18 -04:00
context_tracking.c	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-06-20 08:18:35 -10:00
cpu_pm.c
cpu.c	CPU hotplug: provide a generic helper to disable/enable CPU hotplug	2013-06-12 16:29:44 -07:00
cpuset.c	sched: Rename sched.c as sched/core.c in comments and Documentation	2013-06-19 12:58:42 +02:00
crash_dump.c
cred.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2012-12-18 10:55:28 -08:00
delayacct.c	cputime: Use accessors to read task cputime stats	2013-01-27 19:23:31 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c	move exit_task_namespaces() outside of exit_notify()	2013-06-15 05:39:08 +04:00
extable.c	extable: Flip the sorting message	2013-04-15 13:25:16 +02:00
fork.c	Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block	2013-05-08 11:51:05 -07:00
freezer.c
futex_compat.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-02-23 18:50:11 -08:00
futex.c	futex: Use freezable blocking call	2013-06-25 23:11:19 +02:00
groups.c
hrtimer.c	Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-05-05 13:23:27 -07:00
hung_task.c
irq_work.c	Merge branch 'nohz/printk-v8' into irq/core	2013-02-05 00:48:46 +01:00
itimer.c
jump_label.c
kallsyms.c	kernel: kallsyms: memory override issue, need check destination buffer length	2013-04-15 15:17:26 +09:30
kcmp.c	kcmp: include linux/ptrace.h	2012-12-20 17:40:19 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking: Fix copy/paste errors of "ARCH_INLINE_*_UNLOCK_BH"	2013-05-28 08:50:00 +02:00
Kconfig.preempt
kexec.c	kexec: Use min() and min_t() to simplify logic	2013-04-30 17:04:07 -07:00
kmod.c	usermodehelper: check subprocess_info->path != NULL	2013-05-16 12:01:11 -07:00
kprobes.c	kprobes: Fix to free gone and unused optprobes	2013-05-28 10:37:59 +02:00
ksysfs.c	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-12-11 18:10:49 -08:00
kthread.c	kthread: implement probe_kthread_data()	2013-04-30 17:04:02 -07:00
latencytop.c
lglock.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c	Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block	2013-05-08 11:51:05 -07:00
Makefile	We get rid of the general module prefix confusion with a binary config option,	2013-05-05 10:58:06 -07:00
modsign_certificate.S	CONFIG_SYMBOL_PREFIX: cleanup.	2013-03-15 15:09:43 +10:30
modsign_pubkey.c	keys: use keyring_alloc() to create module signing keyring	2012-12-20 17:40:21 -08:00
module_signing.c	MODSIGN: Don't use enum-type bitfields in module signature info block	2012-12-05 11:27:24 +10:30
module-internal.h
module.c	kmemleak: No need for scanning specific module sections	2013-05-17 09:53:36 +01:00
mutex-debug.c
mutex-debug.h
mutex.c	mutex: Add w/w mutex slowpath debugging	2013-06-26 12:10:56 +02:00
mutex.h
notifier.c
nsproxy.c	proc: Split the namespace stuff out into linux/proc_ns.h	2013-05-01 17:29:39 -04:00
padata.c	padata: use __this_cpu_read per-cpu helper	2012-12-06 17:16:23 +08:00
panic.c	dump_stack: implement arch-specific hardware description in task dumps	2013-04-30 17:04:02 -07:00
params.c	params: Fix potential memory leak in add_sysfs_param()	2013-03-18 11:40:21 +00:00
pid_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
pid.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
posix-cpu-timers.c	posix_timers: Fix pre-condition to stop the tick on full dynticks	2013-04-22 19:59:25 +02:00
posix-timers.c	posix-timers: Remove unused variable	2013-04-18 12:51:19 +02:00
printk.c	kmsg: honor dmesg_restrict sysctl on /dev/kmsg	2013-06-12 16:29:44 -07:00
profile.c	proc: Supply PDE attribute setting accessor functions	2013-05-01 17:29:18 -04:00
ptrace.c	Fix: kernel/ptrace.c: ptrace_peek_siginfo() missing __put_user() validation	2013-06-29 11:29:08 -07:00
range.c	range: Do not add new blank slot with add_range_with_merge	2013-06-18 11:32:10 -05:00
rcu.h	rcu: Provide RCU CPU stall warnings for tiny RCU	2013-01-28 22:06:21 -08:00
rcupdate.c	Merge branches 'cbnum.2013.06.10a', 'doc.2013.06.10a', 'fixes.2013.06.10a', 'srcu.2013.06.10a' and 'tiny.2013.06.10a' into HEAD	2013-06-10 13:46:44 -07:00
rcutiny_plugin.h	rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs	2013-06-10 13:45:53 -07:00
rcutiny.c	rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs	2013-06-10 13:45:53 -07:00
rcutorture.c	rcu: Remove srcu_read_lock_raw() and srcu_read_unlock_raw().	2013-06-10 13:45:25 -07:00
rcutree_plugin.h	Merge branches 'cbnum.2013.06.10a', 'doc.2013.06.10a', 'fixes.2013.06.10a', 'srcu.2013.06.10a' and 'tiny.2013.06.10a' into HEAD	2013-06-10 13:46:44 -07:00
rcutree_trace.c	rcutrace: single_open() leaks	2013-05-05 00:16:35 -04:00
rcutree.c	Merge branches 'cbnum.2013.06.10a', 'doc.2013.06.10a', 'fixes.2013.06.10a', 'srcu.2013.06.10a' and 'tiny.2013.06.10a' into HEAD	2013-06-10 13:46:44 -07:00
rcutree.h	rcu: Drive quiescent-state-forcing delay from HZ	2013-06-10 13:44:56 -07:00
relay.c	Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block	2013-05-08 10:13:35 -07:00
res_counter.c	res_counter: return amount of charges after res_counter_uncharge()	2012-12-18 15:02:12 -08:00
resource.c	ACPI/APEI: Add parameter check before error injection	2013-06-06 15:20:51 -07:00
rtmutex_common.h
rtmutex-debug.c	sched/rt: Move rt specific bits into new header file	2013-02-07 20:51:08 +01:00
rtmutex-debug.h
rtmutex-tester.c	locking/rtmutex/tester: Set correct permissions on sysfs files	2013-04-10 14:48:37 +02:00
rtmutex.c	rtmutex: Document rt_mutex_adjust_prio_chain()	2013-05-28 09:23:52 +02:00
rtmutex.h
rwsem.c	Revert "rw_semaphore: remove up/down_read_non_owner"	2013-03-23 15:53:52 -07:00
seccomp.c	seccomp: allow BPF_XOR based ALU instructions.	2013-03-26 11:07:19 +11:00
semaphore.c	semaphore: use `bool' type for semaphore_waiter's up	2013-04-30 17:04:08 -07:00
signal.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
smp.c	kernel/smp.c: cleanups	2013-04-30 17:04:03 -07:00
smpboot.c	kthread: Prevent unpark race which puts threads on the wrong cpu	2013-04-12 14:18:43 +02:00
smpboot.h
softirq.c	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-07-02 16:14:35 -07:00
spinlock.c
srcu.c	srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()	2013-02-07 15:19:36 -08:00
stacktrace.c
stop_machine.c	stop_machine: Mark per cpu stopper enabled early	2013-02-26 22:25:17 +01:00
sys_ni.c	unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE	2013-05-09 13:46:38 -04:00
sys.c	reboot: rigrate shutdown/reboot to boot cpu	2013-06-12 16:29:44 -07:00
sysctl_binary.c	switch compat_sys_sysctl to COMPAT_SYSCALL_DEFINE	2013-05-09 14:53:20 -04:00
sysctl.c	perf: Drop sample rate when sampling is too slow	2013-06-23 11:52:57 +02:00
task_work.c
taskstats.c
test_kprobes.c	kernel/: rename random32() to prandom_u32()	2013-04-29 18:28:42 -07:00
time.c	sched: Rename sched.c as sched/core.c in comments and Documentation	2013-06-19 12:58:42 +02:00
timeconst.bc	kernel: Replace timeconst.pl with a bc script	2013-02-16 23:17:25 +01:00
timer.c	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-05-15 14:05:17 -07:00
tracepoint.c	Tracing updates for Linux 3.10	2013-04-29 13:55:38 -07:00
tsacct.c	cputime: Use accessors to read task cputime stats	2013-01-27 19:23:31 +01:00
uid16.c	make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect	2013-03-03 22:58:33 -05:00
up.c
user_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
user-return-notifier.c	hlist: drop the node parameter from iterators	2013-02-27 19:10:24 -08:00
user.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
utsname_sysctl.c	kernel/utsname_sysctl.c: put get/get_uts() into CONFIG_PROC_SYSCTL code block	2013-02-27 19:10:22 -08:00
utsname.c	proc: Split the namespace stuff out into linux/proc_ns.h	2013-05-01 17:29:39 -04:00
wait.c	Add wait_on_atomic_t() and wake_up_atomic_t()	2013-05-15 13:50:38 +01:00
watchdog.c	watchdog: Add comments to explain the watchdog_disabled variable	2013-03-14 08:24:05 +01:00
workqueue_internal.h	sched: Rename sched.c as sched/core.c in comments and Documentation	2013-06-19 12:58:42 +02:00
workqueue.c	workqueue: don't perform NUMA-aware allocations on offline nodes in wq_numa_init()	2013-05-15 14:24:24 -07:00