kernel_optimize_test/kernel
Frederic Weisbecker 280f06774a nohz: Separate out irq exit and idle loop dyntick logic
The tick_nohz_stop_sched_tick() function, which tries to delay
the next timer tick as long as possible, can be called from two
places:

- From the idle loop to start the dytick idle mode
- From interrupt exit if we have interrupted the dyntick
idle mode, so that we reprogram the next tick event in
case the irq changed some internal state that requires this
action.

There are only few minor differences between both that
are handled by that function, driven by the ts->inidle
cpu variable and the inidle parameter. The whole guarantees
that we only update the dyntick mode on irq exit if we actually
interrupted the dyntick idle mode, and that we enter in RCU extended
quiescent state from idle loop entry only.

Split this function into:

- tick_nohz_idle_enter(), which sets ts->inidle to 1, enters
dynticks idle mode unconditionally if it can, and enters into RCU
extended quiescent state.

- tick_nohz_irq_exit() which only updates the dynticks idle mode
when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called).

To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed
into tick_nohz_idle_exit().

This simplifies the code and micro-optimize the irq exit path (no need
for local_irq_save there). This also prepares for the split between
dynticks and rcu extended quiescent state logics. We'll need this split to
further fix illegal uses of RCU in extended quiescent states in the idle
loop.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-12-11 10:31:35 -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: Separate out irq exit and idle loop dyntick logic 2011-12-11 10:31:35 -08:00
trace trace: Allow ftrace_dump() to be called from modules 2011-12-11 10:31:25 -08:00
.gitignore
acct.c
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
audit.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
audit.h
auditfilter.c
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
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
exit.c oom: remove oom_disable_count 2011-10-31 17:30:45 -07:00
extable.c
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
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
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 [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.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
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 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
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
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-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
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_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_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 nohz: Separate out irq exit and idle loop dyntick logic 2011-12-11 10:31:35 -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
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
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.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00