Luis R. Rodriguez d5374226c3 rcu: Use idle versions of swait to make idle-hack clear ... These RCU waits were set to use interruptible waits to avoid the kthreads contributing to system load average, even though they are not interruptible as they are spawned from a kthread. Use the new TASK_IDLE swaits which makes our goal clear, and removes confusion about these paths possibly being interruptible -- they are not. When the system is idle the RCU grace-period kthread will spend all its time blocked inside the swait_event_interruptible(). If the interruptible() was not used, then this kthread would contribute to the load average. This means that an idle system would have a load average of 2 (or 3 if PREEMPT=y), rather than the load average of 0 that almost fifty years of UNIX has conditioned sysadmins to expect. The same argument applies to swait_event_interruptible_timeout() use. The RCU grace-period kthread spends its time blocked inside this call while waiting for grace periods to complete. In particular, if there was only one busy CPU, but that CPU was frequently invoking call_rcu(), then the RCU grace-period kthread would spend almost all its time blocked inside the swait_event_interruptible_timeout(). This would mean that the load average would be 2 rather than the expected 1 for the single busy CPU. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>		2017-08-17 07:26:15 -07:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2017-07-20 16:33:39 -07:00
cgroup	mm, cpuset: always use seqlock when changing task's nodemask	2017-07-06 16:24:34 -07:00
configs	config: android-base: disable CONFIG_NFSD and CONFIG_NFS_FS	2017-06-09 11:47:38 +02:00
debug	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
events	Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-07-21 11:12:48 -07:00
gcov	gcov: support GCC 7.1	2017-05-12 15:57:15 -07:00
irq	genirq/PM: Properly pretend disabled state when force resuming interrupts	2017-07-17 22:32:20 +02:00
livepatch	livepatch: Fix stacking of patches with respect to RCU	2017-06-20 10:42:19 +02:00
locking	Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-07-21 11:11:23 -07:00
power	More power management updates for v4.13-rc1	2017-07-10 15:16:21 -07:00
printk	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk	2017-07-05 11:11:26 -07:00
rcu	rcu: Use idle versions of swait to make idle-hack clear	2017-08-17 07:26:15 -07:00
sched	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-07-21 11:16:12 -07:00
time	Merge branch 'timers-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2017-07-05 15:34:35 -07:00
trace	trace: fix the errors caused by incompatible type of RCU variables	2017-07-20 09:27:29 -04:00
.gitignore
acct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
async.c	async: Adjust system_state checks	2017-05-23 10:01:37 +02:00
audit_fsnotify.c	Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2017-05-03 11:05:15 -07:00
audit_tree.c	Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2017-05-03 11:05:15 -07:00
audit_watch.c	Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2017-05-03 11:05:15 -07:00
audit.c	Merge branch 'stable-4.13' of git://git.infradead.org/users/pcmoore/audit	2017-07-20 10:22:26 -07:00
audit.h	audit: style fix	2017-06-12 18:07:43 -04:00
auditfilter.c	audit: kernel generated netlink traffic should have a portid of 0	2017-05-02 10:16:05 -04:00
auditsc.c	Merge branch 'stable-4.13' of git://git.infradead.org/users/pcmoore/audit	2017-07-05 11:24:05 -07:00
backtracetest.c
bounds.c
capability.c	capability: export has_capability	2017-01-12 07:01:56 -07:00
compat.c	Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2017-07-06 20:57:13 -07:00
configs.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
context_tracking.c
cpu_pm.c
cpu.c	smp/hotplug: Replace BUG_ON and react useful	2017-07-11 22:25:44 +02:00
crash_core.c	kdump: protect vmcoreinfo data under the crash memory	2017-07-12 16:26:00 -07:00
crash_dump.c
cred.c	doc: ReSTify credentials.txt	2017-05-18 10:30:19 -06:00
delayacct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c	rcu: Create reasonable API for do_exit() TASKS_RCU processing	2017-08-17 07:26:05 -07:00
extable.c	lib/extable.c: use bsearch() library function in search_extable()	2017-07-10 16:32:35 -07:00
fork.c	fork,random: use get_random_canary() to set tsk->stack_canary	2017-07-12 16:26:03 -07:00
freezer.c
futex_compat.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
futex.c	Now that IPC and other changes have landed, enable manual markings for	2017-07-19 08:55:18 -07:00
groups.c	kernel/groups.c: use sort library function	2017-07-10 16:32:34 -07:00
hung_task.c	kernel/hung_task.c: defer showing held locks	2017-05-08 17:15:10 -07:00
irq_work.c
jump_label.c	jump_label: Reorder hotplug lock and jump_label_lock	2017-05-26 10:10:45 +02:00
kallsyms.c	kernel/kallsyms.c: replace all_var with IS_ENABLED(CONFIG_KALLSYMS_ALL)	2017-07-10 16:32:34 -07:00
kcmp.c	kcmp: add KCMP_EPOLL_TFD mode to compare epoll target files	2017-07-12 16:26:01 -07:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: simplify interrupt check	2017-05-08 17:15:12 -07:00
kexec_core.c	kdump: protect vmcoreinfo data under the crash memory	2017-07-12 16:26:00 -07:00
kexec_file.c	kexec_file: adjust declaration of kexec_purgatory	2017-07-12 16:26:02 -07:00
kexec_internal.h	kexec_file: adjust declaration of kexec_purgatory	2017-07-12 16:26:02 -07:00
kexec.c	kdump: protect vmcoreinfo data under the crash memory	2017-07-12 16:26:00 -07:00
kmod.c	kmod: throttle kmod thread limit	2017-07-14 15:05:13 -07:00
kprobes.c	kprobes: Ensure that jprobe probepoints are at function entry	2017-07-08 11:05:35 +02:00
ksysfs.c	kexec: move vmcoreinfo out of the kernel's .bss section	2017-07-12 16:25:59 -07:00
kthread.c	cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups	2017-03-17 10:18:47 -04:00
latencytop.c	sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h>	2017-03-02 08:42:39 +01:00
Makefile	kernel/watchdog: split up config options	2017-07-12 16:26:02 -07:00
membarrier.c	Fix: Disable sys_membarrier when nohz_full is enabled	2017-01-23 11:32:16 -08:00
memremap.c	mm, memory_hotplug: replace for_device by want_memblock in arch_add_memory	2017-07-06 16:24:32 -07:00
module_signing.c
module-internal.h
module.c	Modules updates for v4.13	2017-07-12 17:22:01 -07:00
notifier.c	kernel/notifier.c: simplify expression	2017-02-24 17:46:56 -08:00
nsproxy.c	perf: Add PERF_RECORD_NAMESPACES to include namespaces related info	2017-03-13 15:57:41 -03:00
padata.c	padata: Avoid nested calls to cpus_read_lock() in pcrypt_init_padata()	2017-05-26 10:10:37 +02:00
panic.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
params.c	boot/param: Move next_arg() function to lib/cmdline.c for later reuse	2017-04-18 10:37:13 +02:00
pid_namespace.c	pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes	2017-05-13 17:26:01 -05:00
pid.c	mm: update callers to use HASH_ZERO flag	2017-07-06 16:24:33 -07:00
profile.c	sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h>	2017-03-02 08:42:39 +01:00
ptrace.c	ptrace: Properly initialize ptracer_cred on fork	2017-05-23 07:40:44 -05:00
range.c
reboot.c
relay.c	Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2017-05-02 11:38:06 -07:00
resource.c
seccomp.c	seccomp: Switch from atomic_t to recount_t	2017-06-26 09:24:00 -07:00
signal.c	kernel/signal.c: avoid undefined behaviour in kill_something_info	2017-07-10 16:32:36 -07:00
smp.c	smp, cpumask: Use non-atomic cpumask_{set,clear}_cpu()	2017-05-23 10:01:32 +02:00
smpboot.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
smpboot.h
softirq.c	sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags()	2017-04-11 09:06:32 +02:00
stacktrace.c	stacktrace/x86: add function for detecting reliable stack traces	2017-03-08 09:18:02 +01:00
stop_machine.c	stop_machine: Provide stop_machine_cpuslocked()	2017-05-26 10:10:36 +02:00
sys_ni.c	move aio compat to fs/aio.c	2016-12-22 22:58:37 -05:00
sys.c	fix a braino in compat_sys_getrlimit()	2017-07-12 09:15:00 -07:00
sysctl_binary.c	kernel/sysctl_binary.c: check name array length in deprecated_sysctl_warning()	2017-07-12 16:26:00 -07:00
sysctl.c	kernel/watchdog: split up config options	2017-07-12 16:26:02 -07:00
task_work.c
taskstats.c	taskstats: add e/u/stime for TGID command	2017-05-08 17:15:12 -07:00
test_kprobes.c
torture.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>	2017-03-02 08:42:27 +01:00
tracepoint.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
tsacct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
ucount.c	ucount: Remove the atomicity from ucount->count	2017-03-06 15:26:37 -06:00
uid16.c	sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>	2017-03-02 08:42:31 +01:00
up.c
user_namespace.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>	2017-03-02 08:42:29 +01:00
user-return-notifier.c
user.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h>	2017-03-02 08:42:29 +01:00
utsname_sysctl.c	sched/headers: Remove <linux/rwsem.h> from <linux/sched.h>	2017-03-03 01:45:36 +01:00
utsname.c	sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h>	2017-03-02 08:42:38 +01:00
watchdog_hld.c	kernel/watchdog: split up config options	2017-07-12 16:26:02 -07:00
watchdog.c	kernel/watchdog.c: use better pr_fmt prefix	2017-07-14 15:05:13 -07:00
workqueue_internal.h
workqueue.c	sched/wait: Rename wait_queue_t => wait_queue_entry_t	2017-06-20 12:18:27 +02:00