Paul E. McKenney e4cc1f22b2 rcu: Simplify quiescent-state accounting ... There is often a delay between the time that a CPU passes through a quiescent state and the time that this quiescent state is reported to the RCU core. It is quite possible that the grace period ended before the quiescent state could be reported, for example, some other CPU might have deduced that this CPU passed through dyntick-idle mode. It is critically important that quiescent state be counted only against the grace period that was in effect at the time that the quiescent state was detected. Previously, this was handled by recording the number of the last grace period to complete when passing through a quiescent state. The RCU core then checks this number against the current value, and rejects the quiescent state if there is a mismatch. However, one additional possibility must be accounted for, namely that the quiescent state was recorded after the prior grace period completed but before the current grace period started. In this case, the RCU core must reject the quiescent state, but the recorded number will match. This is handled when the CPU becomes aware of a new grace period -- at that point, it invalidates any prior quiescent state. This works, but is a bit indirect. The new approach records the current grace period, and the RCU core checks to see (1) that this is still the current grace period and (2) that this grace period has not yet ended. This approach simplifies reasoning about correctness, and this commit changes over to this new approach. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>		2011-09-28 21:38:22 -07:00
..
debug	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb	2011-08-01 13:39:40 -10:00
events	perf_event: Fix broken calc_timer_values()	2011-08-31 15:56:29 +02:00
gcov	gcov: disable CONSTRUCTORS for UML	2011-07-26 16:49:45 -07:00
irq	genirq: Make irq_shutdown() symmetric vs. irq_startup again	2011-09-12 09:38:53 +02:00
power	PM / Domains: Fix build for CONFIG_PM_RUNTIME unset	2011-08-14 13:34:31 +02:00
time	alarmtimers: Avoid possible denial of service with high freq periodic timers	2011-08-10 10:26:09 -07:00
trace	Merge branch 'for-linus' of git://git.kernel.dk/linux-block	2011-08-19 10:47:07 -07:00
.gitignore
acct.c
async.c	async: Fixed an include coding style issue	2011-06-14 22:48:46 -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
audit.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
audit.h
auditfilter.c
auditsc.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c
cgroup.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6	2011-07-27 19:26:38 -07:00
compat.c	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6	2011-07-30 00:08:53 -07:00
configs.c	kernel/configs.c: include MODULE_*() when CONFIG_IKCONFIG_PROC=n	2011-07-25 20:57:15 -07:00
cpu.c
cpuset.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
crash_dump.c
cred.c	move RLIMIT_NPROC check from set_user() to do_execve_common()	2011-08-11 11:24:42 -07:00
delayacct.c	KVM: Steal time implementation	2011-07-14 12:59:14 +03:00
dma.c
elfcore.c
exec_domain.c
exit.c	ipc: introduce shm_rmid_forced sysctl	2011-07-26 16:49:44 -07:00
extable.c
fork.c	move RLIMIT_NPROC check from set_user() to do_execve_common()	2011-08-11 11:24:42 -07:00
freezer.c
futex_compat.c
futex.c	Merge branch 'linus' into core/urgent	2011-08-04 09:09:27 +02:00
groups.c
hrtimer.c
hung_task.c
irq_work.c
itimer.c
jump_label.c	jump_label: Fix jump_label update for modules	2011-06-29 09:59:17 -04:00
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt	sched: Isolate preempt counting in its own config option	2011-06-10 15:15:40 +02:00
kexec.c	treewide: Convert uses of struct resource to resource_size(ptr)	2011-06-10 14:55:36 +02:00
kfifo.c
kmod.c	Boot up with usermodehelper disabled	2011-08-03 22:03:29 -10:00
kprobes.c	kprobes: Return -ENOENT if probe point doesn't exist	2011-07-15 15:11:47 -04:00
ksysfs.c
kthread.c
latencytop.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c	rcu: Restore checks for blocking in RCU read-side critical sections	2011-09-28 21:36:37 -07:00
Makefile	jump label: Reduce the cycle count by changing the link order	2011-08-05 23:57:33 +02:00
module.c	module: add /sys/module/<name>/uevent files	2011-07-24 22:06:04 +09:30
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c	notifiers: sys: move reboot notifiers into reboot.h	2011-07-25 20:57:14 -07:00
nsproxy.c	make sure that nsproxy_cache is initialized early enough	2011-07-20 01:44:07 -04:00
padata.c
panic.c	panic: panic=-1 for immediate reboot	2011-07-26 16:49:45 -07:00
params.c	module: add /sys/module/<name>/uevent files	2011-07-24 22:06:04 +09:30
pid_namespace.c
pid.c	rcu: Restore checks for blocking in RCU read-side critical sections	2011-09-28 21:36:37 -07:00
pm_qos_params.c	plist: Remove the need to supply locks to plist heads	2011-07-08 14:02:53 +02:00
posix-cpu-timers.c
posix-timers.c
printk.c	kernel/printk: do not turn off bootconsole in printk_late_init() if keep_bootcon	2011-08-25 16:25:34 -07:00
profile.c
ptrace.c	ptrace: PTRACE_LISTEN forgets to unlock ->siglock	2011-09-25 11:02:00 -07:00
range.c
rcu.h	rcu: Add grace-period, quiescent-state, and call_rcu trace events	2011-09-28 21:38:21 -07:00
rcupdate.c	rcu: Add event-tracing for RCU callback invocation	2011-09-28 21:38:12 -07:00
rcutiny_plugin.h	rcu: Make TINY_RCU also use softirq for RCU_BOOST=n	2011-09-28 21:38:20 -07:00
rcutiny.c	rcu: Add grace-period, quiescent-state, and call_rcu trace events	2011-09-28 21:38:21 -07:00
rcutorture.c	rcu: Don't destroy rcu_torture_boost() callback until it is done	2011-09-28 21:38:10 -07:00
rcutree_plugin.h	rcu: Simplify quiescent-state accounting	2011-09-28 21:38:22 -07:00
rcutree_trace.c	rcu: Simplify quiescent-state accounting	2011-09-28 21:38:22 -07:00
rcutree.c	rcu: Simplify quiescent-state accounting	2011-09-28 21:38:22 -07:00
rcutree.h	rcu: Simplify quiescent-state accounting	2011-09-28 21:38:22 -07:00
relay.c
res_counter.c
resource.c	resources: Add lookup_resource()	2011-07-30 21:21:39 +02:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c	plist: Remove the need to supply locks to plist heads	2011-07-08 14:02:53 +02:00
rtmutex.h
rwsem.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
sched_autogroup.c
sched_autogroup.h	sched: Skip autogroup when looking for all rt sched groups	2011-07-01 10:39:08 +02:00
sched_clock.c
sched_cpupri.c
sched_cpupri.h
sched_debug.c
sched_fair.c	sched: Cleanup duplicate local variable in [enqueue|dequeue]_task_fair	2011-07-22 12:47:22 +02:00
sched_features.h	Merge branch 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm	2011-07-24 09:07:03 -07:00
sched_idletask.c
sched_rt.c	sched: Skip autogroup when looking for all rt sched groups	2011-07-01 10:39:08 +02:00
sched_stats.h
sched_stoptask.c
sched.c	rcu: Restore checks for blocking in RCU read-side critical sections	2011-09-28 21:36:37 -07:00
seccomp.c
semaphore.c
signal.c	signals: sys_ssetmask/sys_rt_sigsuspend should use set_current_blocked()	2011-07-27 12:53:36 -07:00
smp.c	generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts	2011-06-17 10:17:12 +02:00
softirq.c	softirq,rcu: Inform RCU of irq_exit() activity	2011-07-20 10:50:12 -07:00
spinlock.c
srcu.c
stacktrace.c	stack_trace: Add weak save_stack_trace_regs()	2011-06-14 22:48:52 -04:00
stop_machine.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
sys_ni.c	All Arch: remove linkage for sys_nfsservctl system call	2011-08-26 15:09:58 -07:00
sys.c	Add a personality to report 2.6.x version numbers	2011-08-25 10:17:28 -07:00
sysctl_binary.c	xfs: remove subdirectories	2011-08-12 16:21:35 -05:00
sysctl_check.c	xfs: remove subdirectories	2011-08-12 16:21:35 -05:00
sysctl.c	sysctl,rcu: Convert call_rcu(free_head) to kfree	2011-07-20 14:10:18 -07:00
taskstats.c	Make TASKSTATS require root access	2011-09-19 17:04:37 -07:00
test_kprobes.c
time.c
timeconst.pl
timer.c	timers: Consider slack value in mod_timer()	2011-06-03 15:02:32 +02:00
tracepoint.c
tsacct.c	Make taskstats round statistics down to nearest 1k bytes/events	2011-09-19 17:10:57 -07:00
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
wait.c
watchdog.c	perf, x86: P4 PMU - Introduce event alias feature	2011-07-14 17:25:04 -04:00
workqueue_sched.h
workqueue.c	workqueue: lock cwq access in drain_workqueue	2011-09-14 18:09:38 -07:00