linux/kernel
Paul E. McKenney 3fbfbf7a3b rcu: Add callback-free CPUs
RCU callback execution can add significant OS jitter and also can
degrade both scheduling latency and, in asymmetric multiprocessors,
energy efficiency.  This commit therefore adds the ability for selected
CPUs ("rcu_nocbs=" boot parameter) to have their callbacks offloaded
to kthreads.  If the "rcu_nocb_poll" boot parameter is also specified,
these kthreads will do polling, removing the need for the offloaded
CPUs to do wakeups.  At least one CPU must be doing normal callback
processing: currently CPU 0 cannot be selected as a no-CBs CPU.
In addition, attempts to offline the last normal-CBs CPU will fail.

This feature was inspired by Jim Houston's and Joe Korty's JRCU, and
this commit includes fixes to problems located by Fengguang Wu's
kbuild test robot.

[ paulmck: Added gfp.h include file as suggested by Fengguang Wu. ]

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-11-16 10:05:56 -08:00
..
debug KGDB/KDB fixes and cleanups 2012-10-13 11:16:58 +09:00
events Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-13 10:20:11 +09:00
gcov
irq irqdomain: augment add_simple() to allocate descs 2012-10-10 08:57:26 +02:00
power Merge branch 'pm-qos' 2012-09-17 20:25:51 +02:00
sched Merge branches 'urgent.2012.10.27a', 'doc.2012.11.16a', 'fixes.2012.11.13a', 'srcu.2012.10.27a', 'stall.2012.11.13a', 'tracing.2012.11.08a' and 'idle.2012.10.24a' into HEAD 2012-11-16 09:59:58 -08:00
time Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-12 22:17:48 +09:00
trace Merge branch 'virtio-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-07 21:04:56 +09:00
.gitignore
acct.c vfs: make path_openat take a struct filename pointer 2012-10-12 20:15:09 -04:00
async.c [SCSI] async: make async_synchronize_full() flush all work regardless of domain 2012-07-20 09:07:37 +01:00
audit_tree.c audit: clean up refcounting in audit-tree 2012-08-15 12:55:22 +02:00
audit_watch.c audit: optimize audit_compare_dname_path 2012-10-12 00:32:02 -04:00
audit.c fs: handle failed audit_log_start properly 2012-10-09 23:33:37 -04:00
audit.h audit: optimize audit_compare_dname_path 2012-10-12 00:32:02 -04:00
auditfilter.c audit: optimize audit_compare_dname_path 2012-10-12 00:32:02 -04:00
auditsc.c audit: make audit_inode take struct filename 2012-10-12 20:15:09 -04:00
backtracetest.c
bounds.c
capability.c userns: Teach inode_capable to understand inodes whose uids map to other namespaces. 2012-05-15 14:59:24 -07:00
cgroup_freezer.c cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them 2012-09-14 12:01:16 -07:00
cgroup.c Merge branch 'for-3.7-hierarchy' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2012-10-02 10:52:28 -07:00
compat.c new helper: sigsuspend() 2012-05-21 23:52:30 -04:00
configs.c
cpu_pm.c kernel/cpu_pm.c: fix various typos 2012-05-31 17:49:27 -07:00
cpu.c CPU hotplug, debug: detect imbalance between get_online_cpus() and put_online_cpus() 2012-10-09 16:22:15 +09:00
cpuset.c cpusets: Remove/update outdated comments 2012-07-24 13:53:28 +02:00
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 userns: Make credential debugging user namespace safe. 2012-08-23 22:54:18 -07:00
delayacct.c
dma.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
elfcore.c
exec_domain.c
exit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
extable.c extable: Skip sorting if sorted at build time. 2012-04-19 15:06:55 -07:00
fork.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-10 12:02:25 +09:00
freezer.c PM / Freezer: Remove references to TIF_FREEZE in comments 2012-03-04 23:08:54 +01:00
futex_compat.c futex: Mark get_robust_list as deprecated 2012-03-29 11:37:17 +02:00
futex.c futex: Forbid uaddr == uaddr2 in futex_wait_requeue_pi() 2012-07-24 16:02:57 +02:00
groups.c userns: Convert in_group_p and in_egroup_p to use kgid_t 2012-05-03 03:29:33 -07:00
hrtimer.c hrtimer: Update hrtimer base offsets each hrtimer_interrupt 2012-07-11 23:34:39 +02:00
hung_task.c hung task debugging: Inject NMI when hung and going to panic 2012-04-25 12:39:25 +02:00
irq_work.c irq_work: fix compile failure on tile from missing include 2012-04-13 13:15:16 -04:00
itimer.c itimer: Use printk_once instead of WARN_ONCE 2012-04-10 11:00:30 +02:00
jump_label.c jump_label: Export jump_label_rate_limit() 2012-08-06 19:00:35 +03:00
kallsyms.c vsprintf: fix %ps on non symbols when using kallsyms 2012-05-29 16:22:32 -07:00
kcmp.c syscalls, x86: add __NR_kcmp syscall 2012-05-31 17:49:32 -07:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking: Adjust spin lock inlining Kconfig options 2012-09-13 17:56:13 +02:00
Kconfig.preempt locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage 2012-03-23 13:18:57 +01:00
kexec.c kdump: remove unneeded include 2012-10-06 03:05:19 +09:00
kfifo.c [media] kernel:kfifo: export __kfifo_max_r symbol 2012-04-11 18:24:37 -03:00
kmod.c infrastructure for saner ret_from_kernel_thread semantics 2012-10-12 13:35:07 -04:00
kprobes.c kprobes/x86: Fix to support jprobes on ftrace-based kprobe 2012-09-13 22:52:11 -04:00
ksysfs.c rcu: Add a module parameter to force use of expedited RCU primitives 2012-10-23 14:54:08 -07:00
kthread.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-13 10:05:52 +09:00
latencytop.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
lglock.c brlocks/lglocks: turn into functions 2012-05-29 23:28:41 -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 lockdep: Check if nested lock is actually held 2012-09-13 17:00:44 +02:00
Makefile Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
modsign_pubkey.c MODSIGN: Provide module signing public keys to the kernel 2012-10-10 20:01:22 +10:30
module_signing.c MODSIGN: Move the magic string to the end of a module and eliminate the search 2012-10-19 17:30:40 -07:00
module-internal.h MODSIGN: Move the magic string to the end of a module and eliminate the search 2012-10-19 17:30:40 -07:00
module.c MODSIGN: Move the magic string to the end of a module and eliminate the search 2012-10-19 17:30:40 -07:00
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.c sched/rt: Use schedule_preempt_disabled() 2012-03-01 10:28:03 +01:00
mutex.h
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 padata: Fix cpu hotplug 2012-03-29 19:52:46 +08:00
panic.c panic: fix a possible deadlock in panic() 2012-07-30 17:25:13 -07:00
params.c params: replace printk(KERN_<LVL>...) with pr_<lvl>(...) 2012-05-04 17:28:18 -07:00
pid_namespace.c pidns: remove recursion from free_pid_ns() 2012-10-19 14:07:47 -07:00
pid.c net ip6 flowlabel: Make owner a union of struct pid * and kuid_t 2012-08-14 21:49:25 -07:00
posix-cpu-timers.c [S390] cputime: add sparse checking and cleanup 2011-12-15 14:56:19 +01:00
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: Fix scheduling-while-atomic problem in console_cpu_notify() 2012-10-16 18:17:44 -07:00
profile.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
ptrace.c ptrace: mark __ptrace_may_access() static 2012-08-03 14:47:17 +10:00
range.c range: fix bogus misuse of module.h to get printk() 2011-10-31 09:20:11 -04:00
rcu.h rcu: Add a module parameter to force use of expedited RCU primitives 2012-10-23 14:54:08 -07:00
rcupdate.c rcu: Add a module parameter to force use of expedited RCU primitives 2012-10-23 14:54:08 -07:00
rcutiny_plugin.h rcu: Add a module parameter to force use of expedited RCU primitives 2012-10-23 14:54:08 -07:00
rcutiny.c rcu: Fix TINY_RCU rcu_is_cpu_rrupt_from_idle check 2012-11-13 14:08:34 -08:00
rcutorture.c Merge branches 'urgent.2012.10.27a', 'doc.2012.11.16a', 'fixes.2012.11.13a', 'srcu.2012.10.27a', 'stall.2012.11.13a', 'tracing.2012.11.08a' and 'idle.2012.10.24a' into HEAD 2012-11-16 09:59:58 -08:00
rcutree_plugin.h rcu: Add callback-free CPUs 2012-11-16 10:05:56 -08:00
rcutree_trace.c rcu: Add callback-free CPUs 2012-11-16 10:05:56 -08:00
rcutree.c rcu: Add callback-free CPUs 2012-11-16 10:05:56 -08:00
rcutree.h rcu: Add callback-free CPUs 2012-11-16 10:05:56 -08:00
relay.c splice: fix racy pipe->buffers uses 2012-06-13 21:16:42 +02:00
res_counter.c rescounters: add res_counter_uncharge_until() 2012-05-29 16:22:27 -07:00
resource.c kernel/resource.c: fix stack overflow in __reserve_region_with_split() 2012-10-06 03:05:31 +09:00
rtmutex_common.h
rtmutex-debug.c lockdep, rtmutex, bug: Show taint flags on error 2011-12-06 08:16:49 +01:00
rtmutex-debug.h
rtmutex-tester.c rtmutex-tester: convert sysdev_class to a regular subsystem 2011-12-14 14:54:22 -08:00
rtmutex.c Revert "rcu: Permit rt_mutex_unlock() with irqs disabled" 2011-12-11 10:33:18 -08:00
rtmutex.h
rwsem.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
seccomp.c seccomp: fix build warnings when there is no CONFIG_SECCOMP_FILTER 2012-04-18 12:24:52 +10:00
semaphore.c semaphore: fix improper comment reference to mutex 2012-04-05 17:15:55 -07:00
signal.c coredump: pass siginfo_t* to do_coredump() and below, not merely signr 2012-10-06 03:05:16 +09:00
smp.c smp: Remove ipi_call_lock[_irq]()/ipi_call_unlock[_irq]() 2012-06-05 17:27:14 +02:00
smpboot.c hotplug: Fix UP bug in smpboot hotplug code 2012-08-13 17:01:07 +02:00
smpboot.h smpboot: Provide infrastructure for percpu hotplug threads 2012-08-13 17:01:07 +02:00
softirq.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-10-01 10:43:39 -07:00
spinlock.c locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage 2012-03-23 13:18:57 +01:00
srcu.c Merge branches 'urgent.2012.10.27a', 'doc.2012.11.16a', 'fixes.2012.11.13a', 'srcu.2012.10.27a', 'stall.2012.11.13a', 'tracing.2012.11.08a' and 'idle.2012.10.24a' into HEAD 2012-11-16 09:59:58 -08:00
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 syscalls, x86: add __NR_kcmp syscall 2012-05-31 17:49:32 -07:00
sys.c use clamp_t in UNAME26 fix 2012-10-19 18:51:17 -07:00
sysctl_binary.c mm: prepare for removal of obsolete /proc/sys/vm/nr_pdflush_threads 2012-07-31 18:42:40 -07:00
sysctl.c Kconfig: clean up the "#if defined(arch)" list for exception-trace sysctl entry 2012-10-09 16:22:14 +09:00
task_work.c task_work: task_work_add() should not succeed after exit_task_work() 2012-09-13 16:47:34 +02:00
taskstats.c taskstats: cgroupstats_user_cmd() may leak on error 2012-10-06 03:05:31 +09:00
test_kprobes.c
time.c time: Move update_vsyscall definitions to timekeeper_internal.h 2012-09-24 12:38:06 -04:00
timeconst.pl
timer.c timers: Fix endless looping between cascade() and internal_add_timer() 2012-10-09 21:27:14 +02:00
tracepoint.c static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]() 2012-02-24 10:05:59 +01:00
tsacct.c userns: Convert taskstats to handle the user and pid namespaces. 2012-09-18 01:01:32 -07:00
uid16.c userns: Convert setting and getting uid and gid system calls to use kuid and kgid 2012-05-03 03:28:41 -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 userns: Add kprojid_t and associated infrastructure in projid.h 2012-09-18 01:01:37 -07:00
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 userns: Add kprojid_t and associated infrastructure in projid.h 2012-09-18 01:01:37 -07:00
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 userns: Use cred->user_ns instead of cred->user->user_ns 2012-04-07 16:55:51 -07:00
wait.c lockdep/waitqueues: Add better annotation 2011-12-21 10:07:39 +01:00
watchdog.c watchdog: Use hotplug thread infrastructure 2012-08-13 17:01:07 +02:00
workqueue_sched.h
workqueue.c Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2012-10-02 09:54:49 -07:00