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e1f47d891c
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Steven Rostedt e1f47d891c sched: RT-balance, avoid overloading 
This patch changes the searching for a run queue by a waking RT task
to try to pick another runqueue if the currently running task
is an RT task.

The reason is that RT tasks behave different than normal
tasks. Preempting a normal task to run a RT task to keep
its cache hot is fine, because the preempted non-RT task
may wait on that same runqueue to run again unless the
migration thread comes along and pulls it off.

RT tasks behave differently. If one is preempted, it makes
an active effort to continue to run. So by having a high
priority task preempt a lower priority RT task, that lower
RT task will then quickly try to run on another runqueue.
This will cause that lower RT task to replace its nice
hot cache (and TLB) with a completely cold one. This is
for the hope that the new high priority RT task will keep
 its cache hot.

Remeber that this high priority RT task was just woken up.
So it may likely have been sleeping for several milliseconds,
and will end up with a cold cache anyway. RT tasks run till
they voluntarily stop, or are preempted by a higher priority
task. This means that it is unlikely that the woken RT task
will have a hot cache to wake up to. So pushing off a lower
RT task is just killing its cache for no good reason.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:12 +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
acct.c acct: real_parent ppid 2008-01-07 14:55:37 -08:00
audit_tree.c [PATCH] audit: watching subtrees 2007-10-21 02:37:45 -04:00
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
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_debug.c Task Control Groups: simple task cgroup debug info subsystem 2007-10-19 11:53:36 -07:00
cgroup.c Improve cgroup printks 2007-11-14 18:45:37 -08:00
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
fork.c sched: add RT-balance cpu-weight 2008-01-25 21:08:07 +01:00
futex_compat.c [FUTEX] Fix address computation in compat code. 2007-11-09 16:13:08 -08:00
futex.c futex: Prevent stale futex owner when interrupted/timeout 2008-01-08 16:21:39 -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
Kconfig.hz
Kconfig.instrumentation Tiny clean-up of OPROFILE/KPROBES configuration 2007-12-06 09:41:12 -08:00
Kconfig.preempt Move PREEMPT_NOTIFIERS into an always-included Kconfig 2007-10-17 08:42:55 -07:00
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
lockdep_internals.h
lockdep_proc.c lockdep: Avoid /proc/lockdep & lock_stat infinite output 2007-10-11 22:11:11 +02:00
lockdep.c softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks 2008-01-25 21:08:02 +01:00
Makefile revert "Task Control Groups: example CPU accounting subsystem" 2007-11-14 18:45:40 -08:00
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
mutex.c lockdep: fixup mutex annotations 2007-10-11 22:11:12 +02:00
mutex.h
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 Isolate some explicit usage of task->tgid 2007-10-19 11:53:40 -07:00
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
rcupdate.c rcu: fix section mismatch 2008-01-22 09:17:48 -08:00
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_common.h FUTEX: Tidy up the code 2007-07-16 09:05:49 -07:00
rtmutex-debug.c Use helpers to obtain task pid in printks 2007-10-19 11:53:43 -07:00
rtmutex-debug.h
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
rwsem.c sched: mark rwsem functions as __sched for wchan/profiling 2007-12-18 15:21:13 +01:00
sched_debug.c sched: fix gcc warnings 2007-12-30 17:24:35 +01:00
sched_fair.c sched: de-SCHED_OTHER-ize the RT path 2008-01-25 21:08:09 +01:00
sched_idletask.c sched: de-SCHED_OTHER-ize the RT path 2008-01-25 21:08:09 +01:00
sched_rt.c sched: RT-balance, avoid overloading 2008-01-25 21:08:12 +01:00
sched_stats.h sched: clean up kernel/sched_stat.h 2007-11-28 15:52:56 +01:00
sched.c sched: wake-balance fixes 2008-01-25 21:08:12 +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
stacktrace.c
stop_machine.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
sys_ni.c [COMPAT]: Fix build on COMPAT platforms when CONFIG_NET is disabled. 2007-10-30 21:29:56 -07:00
sys.c x86: ignore the sys_getcpu() tcache parameter 2007-11-17 16:27:00 +01:00
sysctl_check.c sysctl: fix ax25 checks 2007-12-17 19:28:17 -08:00
sysctl.c softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks 2008-01-25 21:08:02 +01:00
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_namespace.c Fix user namespace exiting OOPs 2007-09-19 11:24:18 -07:00
user.c Kobject: convert kernel/user.c to use kobject_init/add_ng() 2008-01-24 20:40:31 -08:00
utsname_sysctl.c Isolate the UTS namespace's domainname and hostname back 2007-11-29 09:24:53 -08:00
utsname.c Fix UTS corruption during clone(CLONE_NEWUTS) 2007-09-19 11:24:17 -07:00
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