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
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
perf_event: Fix broken calc_timer_values()
2011-08-31 15:56:29 +02:00
gcov: disable CONSTRUCTORS for UML
2011-07-26 16:49:45 -07:00
genirq: Make irq_shutdown() symmetric vs. irq_startup again
2011-09-12 09:38:53 +02:00
PM / Domains: Fix build for CONFIG_PM_RUNTIME unset
2011-08-14 13:34:31 +02:00
alarmtimers: Avoid possible denial of service with high freq periodic timers
2011-08-10 10:26:09 -07:00
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
2011-08-19 10:47:07 -07:00
async: Fixed an include coding style issue
2011-06-14 22:48:46 -04:00
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
audit: make functions static
2010-10-30 01:42:19 -04:00
audit_tree,rcu: Convert call_rcu(__put_tree) to kfree_rcu()
2011-07-20 14:10:11 -07:00
kill path_lookup()
2011-03-14 09:15:23 -04:00
netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms
2011-03-03 10:55:40 -08:00
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
memcg: remove direct page_cgroup-to-page pointer
2011-03-23 19:46:28 -07:00
Merge branch 'master' into next
2011-05-19 18:51:57 +10:00
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
cgroups: add per-thread subsystem callbacks
2011-05-26 17:12:34 -07:00
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
kernel/configs.c: include MODULE_*() when CONFIG_IKCONFIG_PROC=n
2011-07-25 20:57:15 -07:00
Fix common misspellings
2011-03-31 11:26:23 -03:00
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn
2011-03-23 19:47:19 -07:00
move RLIMIT_NPROC check from set_user() to do_execve_common()
2011-08-11 11:24:42 -07:00
KVM: Steal time implementation
2011-07-14 12:59:14 +03:00
ipc: introduce shm_rmid_forced sysctl
2011-07-26 16:49:44 -07:00
extable, core_kernel_data(): Make sure all archs define _sdata
2011-05-20 08:56:56 +02:00
move RLIMIT_NPROC check from set_user() to do_execve_common()
2011-08-11 11:24:42 -07:00
Freezer: Use SMP barriers
2011-05-17 23:19:17 +02:00
Merge branch 'linus' into core/urgent
2011-08-04 09:09:27 +02:00
userns: user namespaces: convert several capable() calls
2011-03-23 19:47:08 -07:00
userns: user namespaces: convert several capable() calls
2011-03-23 19:47:08 -07:00
hrtimers: Fix typo causing erratic timers
2011-05-25 15:31:58 -07:00
watchdog, hung_task_timeout: Add Kconfig configurable default
2011-04-28 09:13:17 +02:00
irq_work: Use per cpu atomics instead of regular atomics
2010-12-18 15:54:48 +01:00
jump_label: Fix jump_label update for modules
2011-06-29 09:59:17 -04:00
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
arch:Kconfig.locks Remove unused config option.
2011-04-10 17:01:05 +02:00
sched: Isolate preempt counting in its own config option
2011-06-10 15:15:40 +02:00
treewide: Convert uses of struct resource to resource_size(ptr)
2011-06-10 14:55:36 +02:00
kfifo: fix scatterlist usage
2010-10-01 10:50:58 -07:00
Boot up with usermodehelper disabled
2011-08-03 22:03:29 -10:00
kprobes: Return -ENOENT if probe point doesn't exist
2011-07-15 15:11:47 -04:00
kernel/ksysfs.c: expose file_caps_enabled in sysfs
2011-04-19 16:45:51 -07:00
cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed
2011-05-28 17:02:57 +02:00
Fix common misspellings
2011-03-31 11:26:23 -03:00
rcu: Restore checks for blocking in RCU read-side critical sections
2011-09-28 21:36:37 -07:00
lockdep: Remove unused 'factor' variable from lockdep_stats_show()
2011-03-23 13:54:47 +01:00
jump label: Reduce the cycle count by changing the link order
2011-08-05 23:57:33 +02:00
module: add /sys/module/<name>/uevent files
2011-07-24 22:06:04 +09:30
mutex: Use p->on_cpu for the adaptive spin
2011-04-14 08:52:33 +02:00
mutex: Use p->on_cpu for the adaptive spin
2011-04-14 08:52:33 +02:00
lockdep, mutex: provide mutex_lock_nest_lock
2011-05-25 08:39:17 -07:00
mutex: Use p->on_cpu for the adaptive spin
2011-04-14 08:52:33 +02:00
notifiers: sys: move reboot notifiers into reboot.h
2011-07-25 20:57:14 -07:00
make sure that nsproxy_cache is initialized early enough
2011-07-20 01:44:07 -04:00
Fix common misspellings
2011-03-31 11:26:23 -03:00
panic: panic=-1 for immediate reboot
2011-07-26 16:49:45 -07:00
module: add /sys/module/<name>/uevent files
2011-07-24 22:06:04 +09:30
rcu: Restore checks for blocking in RCU read-side critical sections
2011-09-28 21:36:37 -07:00
pidns: call pid_ns_prepare_proc() from create_pid_namespace()
2011-03-23 19:46:58 -07:00
plist: Remove the need to supply locks to plist heads
2011-07-08 14:02:53 +02:00
hrtimers: Avoid touching inactive timer bases
2011-05-23 13:59:54 +02:00
posix-timers: RCU conversion
2011-05-24 12:10:51 +02:00
kernel/printk: do not turn off bootconsole in printk_late_init() if keep_bootcon
2011-08-25 16:25:34 -07:00
kernel/profile.c: remove some duplicate code from profile_hits()
2011-05-26 17:12:37 -07:00
ptrace: PTRACE_LISTEN forgets to unlock ->siglock
2011-09-25 11:02:00 -07:00
kernel/range.c: fix clean_sort_range() for the case of full array
2010-11-12 07:55:31 -08:00
rcu: Add grace-period, quiescent-state, and call_rcu trace events
2011-09-28 21:38:21 -07:00
rcu: Add event-tracing for RCU callback invocation
2011-09-28 21:38:12 -07:00
rcu: Add grace-period, quiescent-state, and call_rcu trace events
2011-09-28 21:38:21 -07:00
rcu: Make TINY_RCU also use softirq for RCU_BOOST=n
2011-09-28 21:38:20 -07:00
rcu: Don't destroy rcu_torture_boost() callback until it is done
2011-09-28 21:38:10 -07:00
rcu: Simplify quiescent-state accounting
2011-09-28 21:38:22 -07:00
rcu: Simplify quiescent-state accounting
2011-09-28 21:38:22 -07:00
rcu: Simplify quiescent-state accounting
2011-09-28 21:38:22 -07:00
rcu: Simplify quiescent-state accounting
2011-09-28 21:38:22 -07:00
Clean up relay_alloc_page_array() slightly by using vzalloc rather than vmalloc and memset
2010-11-05 08:21:34 -07:00
memcg: res_counter_read_u64(): fix potential races on 32-bit machines
2011-03-23 19:46:22 -07:00
resources: Add lookup_resource()
2011-07-30 21:21:39 +02:00
rtmutex: Simplify PI algorithm and make highest prio task get lock
2011-01-27 21:13:51 -05:00
rtmutex: tester: Remove the remaining BKL leftovers
2011-02-22 22:07:22 +01:00
plist: Remove the need to supply locks to plist heads
2011-07-08 14:02:53 +02:00
rtmutex: Simplify PI algorithm and make highest prio task get lock
2011-01-27 21:13:51 -05:00
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
rcu: Restore checks for blocking in RCU read-side critical sections
2011-09-28 21:36:37 -07:00
Fix common misspellings
2011-03-31 11:26:23 -03:00
sched: Skip autogroup when looking for all rt sched groups
2011-07-01 10:39:08 +02:00
sched: Add some clock info to sched_debug
2010-11-23 10:29:08 +01:00
sched: Get rid of lock_depth
2011-04-24 13:18:38 +02:00
sched: Cleanup duplicate local variable in [enqueue|dequeue]_task_fair
2011-07-22 12:47:22 +02:00
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: Drop the rq argument to sched_class::select_task_rq()
2011-04-14 08:52:36 +02:00
sched: Skip autogroup when looking for all rt sched groups
2011-07-01 10:39:08 +02:00
sched: More sched_domain iterations fixes
2011-05-28 17:02:54 +02:00
sched: Drop the rq argument to sched_class::select_task_rq()
2011-04-14 08:52:36 +02:00
signals: sys_ssetmask/sys_rt_sigsuspend should use set_current_blocked()
2011-07-27 12:53:36 -07:00
generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts
2011-06-17 10:17:12 +02:00
softirq,rcu: Inform RCU of irq_exit() activity
2011-07-20 10:50:12 -07:00
rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status
2011-01-14 04:56:49 -08:00
stack_trace: Add weak save_stack_trace_regs()
2011-06-14 22:48:52 -04:00
atomic: use <linux/atomic.h>
2011-07-26 16:49:47 -07:00
Add a personality to report 2.6.x version numbers
2011-08-25 10:17:28 -07:00
All Arch: remove linkage for sys_nfsservctl system call
2011-08-26 15:09:58 -07:00
sysctl,rcu: Convert call_rcu(free_head) to kfree
2011-07-20 14:10:18 -07:00
xfs: remove subdirectories
2011-08-12 16:21:35 -05:00
xfs: remove subdirectories
2011-08-12 16:21:35 -05:00
Make TASKSTATS require root access
2011-09-19 17:04:37 -07:00
kprobes: Fix selftest to clear flags field for reusing probes
2010-10-14 08:55:27 +02:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-03-15 18:53:35 -07:00
timers: Consider slack value in mod_timer()
2011-06-03 15:02:32 +02:00
jump label: Introduce static_branch() interface
2011-04-04 12:48:08 -04:00
Make taskstats round statistics down to nearest 1k bytes/events
2011-09-19 17:10:57 -07:00
userns: user namespaces: convert several capable() calls
2011-03-23 19:47:08 -07:00
Fix common misspellings
2011-03-31 11:26:23 -03:00
userns: add a user_namespace as creator/owner of uts_namespace
2011-03-23 19:46:59 -07:00
user_ns: improve the user_ns on-the-slab packaging
2011-01-13 08:03:18 -08:00
ns proc: Add support for the uts namespace
2011-05-10 14:35:35 -07:00
Fix common misspellings
2011-03-31 11:26:23 -03:00
perf, x86: P4 PMU - Introduce event alias feature
2011-07-14 17:25:04 -04:00
workqueue: lock cwq access in drain_workqueue
2011-09-14 18:09:38 -07:00
e4cc1f22b2