linux/kernel
Peter Zijlstra 8f4d37ec07 sched: high-res preemption tick
Use HR-timers (when available) to deliver an accurate preemption tick.

The regular scheduler tick that runs at 1/HZ can be too coarse when nice
level are used. The fairness system will still keep the cpu utilisation 'fair'
by then delaying the task that got an excessive amount of CPU time but try to
minimize this by delivering preemption points spot-on.

The average frequency of this extra interrupt is sched_latency / nr_latency.
Which need not be higher than 1/HZ, its just that the distribution within the
sched_latency period is important.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:29 +01:00
..
irq genirq: revert lazy irq disable for simple irqs 2007-12-18 18:05:58 +01:00
power driver core: make /sys/power a kobject 2008-01-24 20:40:25 -08:00
time Driver core: change sysdev classes to use dynamic kobject names 2008-01-24 20:40:40 -08:00
.gitignore gitignore: ignore more generated files 2006-01-03 11:35:26 +01:00
Kconfig.hz sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
Kconfig.instrumentation Tiny clean-up of OPROFILE/KPROBES configuration 2007-12-06 09:41:12 -08:00
Kconfig.preempt Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
Makefile Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
acct.c acct: real_parent ppid 2008-01-07 14:55:37 -08:00
audit.c [PATCH] audit: watching subtrees 2007-10-21 02:37:45 -04:00
audit.h [PATCH] audit: watching subtrees 2007-10-21 02:37:45 -04:00
audit_tree.c [PATCH] audit: watching subtrees 2007-10-21 02:37:45 -04:00
auditfilter.c [PATCH] audit: watching subtrees 2007-10-21 02:37:45 -04:00
auditsc.c auditsc: fix kernel-doc param warnings 2007-10-22 19:40:02 -07:00
capability.c Uninline find_pid etc set of functions 2007-10-19 11:53:41 -07:00
cgroup.c Improve cgroup printks 2007-11-14 18:45:37 -08:00
cgroup_debug.c Task Control Groups: simple task cgroup debug info subsystem 2007-10-19 11:53:36 -07:00
compat.c Merge ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt 2007-10-18 15:12:41 -07:00
configs.c use simple_read_from_buffer in kernel/ 2007-05-09 12:30:49 -07:00
cpu.c cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() 2008-01-25 21:08:02 +01:00
cpuset.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
delayacct.c Add scaled time to taskstats based process accounting 2007-10-18 14:37:28 -07:00
dma.c whitespace fixes: DMA channel allocator 2007-10-18 14:37:24 -07:00
exec_domain.c whitespace fixes: execution domains 2007-10-18 14:37:26 -07:00
exit.c wait_task_stopped(): pass correct exit_code to wait_noreap_copyout() 2007-11-29 09:24:55 -08:00
extable.c [PATCH] symbol_put_addr() locks kernel 2006-05-15 11:20:55 -07:00
fork.c Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
futex.c futex: Prevent stale futex owner when interrupted/timeout 2008-01-08 16:21:39 -08:00
futex_compat.c [FUTEX] Fix address computation in compat code. 2007-11-09 16:13:08 -08:00
hrtimer.c hrtimer: fix section mismatch 2008-01-21 19:39:41 -08:00
itimer.c whitespace fixes: interval timers 2007-10-18 14:37:26 -07:00
kallsyms.c FRV: fix the extern declaration of kallsyms_num_syms 2007-11-29 09:24:54 -08:00
kexec.c vmcoreinfo: add the array length of "free_list" for filtering free pages 2008-01-08 16:10:36 -08:00
kfifo.c is_power_of_2: kernel/kfifo.c 2007-07-16 09:05:50 -07:00
kmod.c Fix unbalanced helper_lock in kernel/kmod.c 2008-01-17 15:38:59 -08:00
kprobes.c kprobes: support kretprobe blacklist 2007-10-16 09:43:10 -07:00
ksysfs.c Kobject: convert remaining kobject_unregister() to kobject_put() 2008-01-24 20:40:40 -08:00
kthread.c kthread: silence bogus section mismatch warning 2007-07-31 15:39:42 -07:00
latency.c [PATCH] severing module.h->sched.h 2006-12-04 02:00:22 -05:00
lockdep.c softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks 2008-01-25 21:08:02 +01:00
lockdep_internals.h [PATCH] lockdep: more chains 2006-12-07 08:39:43 -08:00
lockdep_proc.c lockdep: Avoid /proc/lockdep & lock_stat infinite output 2007-10-11 22:11:11 +02:00
marker.c Linux Kernel Markers: fix marker mutex not taken upon module load 2007-11-14 18:45:40 -08:00
module.c Kobject: convert remaining kobject_unregister() to kobject_put() 2008-01-24 20:40:40 -08:00
mutex-debug.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00
mutex-debug.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
mutex.c lockdep: fixup mutex annotations 2007-10-11 22:11:12 +02:00
mutex.h [PATCH] lockdep: prove mutex locking correctness 2006-07-03 15:27:04 -07:00
notifier.c Add kernel/notifier.c 2007-10-19 11:53:34 -07:00
ns_cgroup.c cgroups: implement namespace tracking subsystem 2007-10-19 11:53:37 -07:00
nsproxy.c pid namespaces: allow cloning of new namespace 2007-10-19 11:53:39 -07:00
panic.c debug: add end-of-oops marker 2007-12-20 15:01:17 +01:00
params.c Modules: remove unneeded release function 2008-01-24 20:40:39 -08:00
pid.c pidns: Place under CONFIG_EXPERIMENTAL 2007-11-14 18:45:43 -08:00
posix-cpu-timers.c sched: SCHED_FIFO/SCHED_RR watchdog timer 2008-01-25 21:08:27 +01:00
posix-timers.c Isolate some explicit usage of task->tgid 2007-10-19 11:53:40 -07:00
printk.c sched: remove printk_clock() 2008-01-25 21:07:59 +01:00
profile.c sched: document profile=sleep requiring CONFIG_SCHEDSTATS 2007-10-24 18:23:50 +02:00
ptrace.c ptrace: Call arch_ptrace_attach() when request=PTRACE_TRACEME 2008-01-25 08:31:39 +01:00
rcuclassic.c Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
rcupdate.c Preempt-RCU: fix rcu_barrier for preemptive environment. 2008-01-25 21:08:24 +01:00
rcupreempt.c Preempt-RCU: CPU Hotplug handling 2008-01-25 21:08:25 +01:00
rcupreempt_trace.c Preempt-RCU: implementation 2008-01-25 21:08:24 +01:00
rcutorture.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
relay.c whitespace fixes: relayfs 2007-10-18 14:37:24 -07:00
resource.c Add IORESOUCE_BUSY flag for System RAM 2007-11-14 18:45:39 -08:00
rtmutex-debug.c Use helpers to obtain task pid in printks 2007-10-19 11:53:43 -07:00
rtmutex-debug.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
rtmutex-tester.c Driver core: change sysdev classes to use dynamic kobject names 2008-01-24 20:40:40 -08:00
rtmutex.c Use helpers to obtain task pid in printks 2007-10-19 11:53:43 -07:00
rtmutex.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
rtmutex_common.h FUTEX: Tidy up the code 2007-07-16 09:05:49 -07:00
rwsem.c sched: mark rwsem functions as __sched for wchan/profiling 2007-12-18 15:21:13 +01:00
sched.c sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
sched_debug.c sched: fix gcc warnings 2007-12-30 17:24:35 +01:00
sched_fair.c sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
sched_idletask.c sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
sched_rt.c sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
sched_stats.h sched: clean up kernel/sched_stat.h 2007-11-28 15:52:56 +01:00
seccomp.c make seccomp zerocost in schedule 2007-07-16 09:05:50 -07:00
signal.c sigwait eats blocked default-ignore signals 2007-11-12 16:05:23 -08:00
softirq.c [KERNEL]: Unexport raise_softirq_irqoff 2007-10-10 16:49:18 -07:00
softlockup.c softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks 2008-01-25 21:08:02 +01:00
spinlock.c lockstat: hook into spinlock_t, rwlock_t, rwsem and mutex 2007-07-19 10:04:49 -07:00
srcu.c [PATCH] SRCU: report out-of-memory errors 2006-10-04 07:55:30 -07:00
stacktrace.c [PATCH] lockdep: stacktrace subsystem, core 2006-07-03 15:27:02 -07:00
stop_machine.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
sys.c x86: ignore the sys_getcpu() tcache parameter 2007-11-17 16:27:00 +01:00
sys_ni.c [COMPAT]: Fix build on COMPAT platforms when CONFIG_NET is disabled. 2007-10-30 21:29:56 -07:00
sysctl.c softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks 2008-01-25 21:08:02 +01:00
sysctl_check.c sysctl: fix ax25 checks 2007-12-17 19:28:17 -08:00
taskstats.c kernel/taskstats.c: fix bogus nlmsg_free() 2007-11-14 18:45:44 -08:00
time.c whitespace fixes: time syscalls 2007-10-18 14:37:24 -07:00
timer.c timer: fix section mismatch 2008-01-21 19:39:41 -08:00
tsacct.c Add scaled time to taskstats based process accounting 2007-10-18 14:37:28 -07:00
uid16.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
user.c uids: merge multiple error paths in alloc_uid() into one 2008-01-25 21:08:26 +01:00
user_namespace.c Fix user namespace exiting OOPs 2007-09-19 11:24:18 -07:00
utsname.c Fix UTS corruption during clone(CLONE_NEWUTS) 2007-09-19 11:24:17 -07:00
utsname_sysctl.c Isolate the UTS namespace's domainname and hostname back 2007-11-29 09:24:53 -08:00
wait.c Fix occurrences of "the the " 2007-05-09 08:57:56 +02:00
workqueue.c cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() 2008-01-25 21:08:02 +01:00