linux/kernel
Frederic Weisbecker 265f22a975 sched: Keep at least 1 tick per second for active dynticks tasks
The scheduler doesn't yet fully support environments
with a single task running without a periodic tick.

In order to ensure we still maintain the duties of scheduler_tick(),
keep at least 1 tick per second.

This makes sure that we keep the progression of various scheduler
accounting and background maintainance even with a very low granularity.
Examples include cpu load, sched average, CFS entity vruntime,
avenrun and events such as load balancing, amongst other details
handled in sched_class::task_tick().

This limitation will be removed in the future once we get
these individual items to work in full dynticks CPUs.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-05-04 08:32:02 +02:00
..
cpu idle: Remove GENERIC_IDLE_LOOP config switch 2013-04-17 10:39:38 +02:00
debug KGDB/KDB fixes and cleanups 2013-03-02 08:31:39 -08:00
events Merge commit '8700c95adb03' into timers/nohz 2013-05-02 17:54:19 +02:00
gcov kernel/gcov: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:33 -08:00
irq Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
power Driver core patches for 3.9-rc1 2013-02-21 12:05:51 -08:00
sched sched: Keep at least 1 tick per second for active dynticks tasks 2013-05-04 08:32:02 +02:00
time sched: Keep at least 1 tick per second for active dynticks tasks 2013-05-04 08:32:02 +02:00
trace Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-30 07:41:01 -07:00
.gitignore kernel/hz.bc: ignore. 2013-04-22 07:09:06 -07:00
acct.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
async.c async: rename and redefine async_func_ptr 2013-03-12 13:59:14 -07:00
audit_tree.c kernel/audit_tree.c: tree will leak memory when failure occurs in audit_trim_trees() 2013-04-29 15:54:26 -07:00
audit_watch.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
audit.c audit: don't check if kauditd is valid every time 2013-04-29 15:54:26 -07:00
audit.h audit: remove unnecessary #if CONFIG_AUDIT 2013-04-29 15:54:26 -07:00
auditfilter.c kernel/auditfilter.c: tree and watch will memory leak when failure occurs 2013-04-29 15:54:26 -07:00
auditsc.c kernel/auditsc.c: use kzalloc instead of kmalloc+memset 2013-04-29 15:54:26 -07:00
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: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free() 2012-11-19 08:13:38 -08:00
cgroup.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-30 07:43:28 -07:00
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
configs.c
context_tracking.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
cpu_pm.c kernel/cpu_pm.c: fix various typos 2012-05-31 17:49:27 -07:00
cpu.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:04:55 -08:00
cpuset.c Merge branch 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2013-04-29 19:14:20 -07:00
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 Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
elfcore.c
exec_domain.c
exit.c Revert "lockdep: check that no locks held at freeze time" 2013-03-31 11:38:33 -07:00
extable.c extable: Skip sorting if sorted at build time. 2012-04-19 15:06:55 -07:00
fork.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-30 07:43:28 -07:00
freezer.c freezer: change ptrace_stop/do_signal_stop to use freezable_schedule() 2012-10-26 14:27:49 -07:00
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: fix kernel-doc notation and spello 2013-03-12 20:42:10 -07:00
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 Merge commit '8700c95adb03' into timers/nohz 2013-05-02 17:54:19 +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 Merge branch 'nohz/printk-v8' into irq/core 2013-02-05 00:48:46 +01:00
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 kcmp: include linux/ptrace.h 2012-12-20 17:40:19 -08:00
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 kexec, vmalloc: export additional vmalloc layer information 2013-04-29 15:54:34 -07:00
kmod.c Merge branch 'master' into for-3.9-async 2013-01-23 09:31:01 -08:00
kprobes.c kprobes: Fix a double lock bug of kprobe_mutex 2013-04-18 08:58:38 -07:00
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 Merge branch 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-04-29 19:07:40 -07:00
latencytop.c
lglock.c brlocks/lglocks: turn into functions 2012-05-29 23:28:41 -04:00
lockdep_internals.h
lockdep_proc.c lockdep: Use KSYM_NAME_LEN'ed buffer for __get_key_name() 2012-10-24 12:39:09 +02:00
lockdep_states.h
lockdep.c lockdep: Consolidate bug messages into a single print_lockdep_off() function 2013-04-26 08:37:22 +02:00
Makefile idle: Provide a generic entry point for the idle code 2013-04-08 17:39:23 +02:00
modsign_certificate.S MODSIGN: Avoid using .incbin in C source 2012-12-14 13:06:44 +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 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 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
mutex-debug.c
mutex-debug.h
mutex.c mutex: Back out architecture specific check for negative mutex count 2013-04-19 09:33:36 +02:00
mutex.h
notifier.c
nsproxy.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
padata.c padata: use __this_cpu_read per-cpu helper 2012-12-06 17:16:23 +08:00
panic.c taint: add explicit flag to show whether lock dep is still OK. 2013-01-21 17:17:57 +10:30
params.c params: replace printk(KERN_<LVL>...) with pr_<lvl>(...) 2012-05-04 17:28:18 -07:00
pid_namespace.c pid: Handle the exit of a multi-threaded init. 2013-03-26 03:41:23 -07:00
pid.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
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: convert to idr_alloc() 2013-02-27 19:10:19 -08:00
printk.c printk: fix failure to return error in devkmsg_poll() 2013-04-29 18:28:14 -07:00
profile.c profiling: Remove unused timer hook 2013-01-24 15:37:26 +01:00
ptrace.c uprobes: Add exports for module use 2013-02-08 17:47:13 +01:00
range.c
rcu.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcupdate.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutiny_plugin.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcutiny.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutorture.c rcu: Allow rcutorture to be built at low optimization levels 2013-02-04 12:18:20 -08:00
rcutree_plugin.h Merge commit '8700c95adb03' into timers/nohz 2013-05-02 17:54:19 +02:00
rcutree_trace.c rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks 2013-03-26 08:04:51 -07:00
rcutree.c Merge commit '8700c95adb03' into timers/nohz 2013-05-02 17:54:19 +02:00
rcutree.h Merge commit '8700c95adb03' into timers/nohz 2013-05-02 17:54:19 +02:00
relay.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
res_counter.c res_counter: return amount of charges after res_counter_uncharge() 2012-12-18 15:02:12 -08:00
resource.c mem hotunplug: fix kfree() of bootmem memory 2013-04-29 15:54:40 -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 sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex.h
rwsem.c lockdep, rwsem: provide down_write_nest_lock() 2013-01-11 14:54:55 -08:00
seccomp.c seccomp: Make syscall skipping and nr changes more consistent 2012-10-02 21:14:29 +10:00
semaphore.c semaphore: fix improper comment reference to mutex 2012-04-05 17:15:55 -07:00
signal.c kernel/signal.c: stop info leak via the tkill and the tgkill syscalls 2013-04-17 16:10:45 -07:00
smp.c smp: make smp_call_function_many() use logic similar to smp_call_function_single() 2013-02-21 17:22:20 -08:00
smpboot.c kthread: Prevent unpark race which puts threads on the wrong cpu 2013-04-12 14:18:43 +02:00
smpboot.h smpboot: Provide infrastructure for percpu hotplug threads 2012-08-13 17:01:07 +02:00
softirq.c Merge commit '8700c95adb03' into timers/nohz 2013-05-02 17:54:19 +02:00
spinlock.c locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage 2012-03-23 13:18:57 +01:00
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 module: add syscall to load module from fd 2012-12-14 13:05:22 +10:30
sys.c PM / reboot: call syscore_shutdown() after disable_nonboot_cpus() 2013-04-08 22:10:40 +02:00
sysctl_binary.c sysctl: fix null checking in bin_dn_node_address() 2013-02-27 19:10:21 -08:00
sysctl.c mm: replace hardcoded 3% with admin_reserve_pages knob 2013-04-29 15:54:36 -07:00
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 kernel/: rename random32() to prandom_u32() 2013-04-29 18:28:42 -07:00
time.c time: don't inline EXPORT_SYMBOL functions 2013-02-21 17:22:19 -08:00
timeconst.bc kernel: Replace timeconst.pl with a bc script 2013-02-16 23:17:25 +01:00
timer.c nohz: Rename CONFIG_NO_HZ to CONFIG_NO_HZ_COMMON 2013-04-03 13:56:03 +02:00
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 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
user_namespace.c userns: Changing any namespace id mappings should require privileges 2013-04-14 18:11:32 -07:00
user-return-notifier.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
user.c userns: Restrict when proc and sysfs can be mounted 2013-03-27 07:50:08 -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 kernel/utsname.c: fix wrong comment about clone_uts_ns() 2013-02-27 19:10:22 -08:00
wait.c propagate name change to comments in kernel source 2012-12-06 10:39:54 +01:00
watchdog.c watchdog: Add comments to explain the watchdog_disabled variable 2013-03-14 08:24:05 +01:00
workqueue_internal.h workqueue: directly restore CPU affinity of workers from CPU_ONLINE 2013-03-19 13:45:21 -07:00
workqueue.c workqueue: use kmem_cache_free() instead of kfree() 2013-04-09 11:33:40 -07:00