linux/kernel
Vaidyanathan Srinivasan 7eb52dfa70 sched: bias task wakeups to preferred semi-idle packages
Impact: tweak task wakeup to save power more agressively

Preferred wakeup cpu (from a semi idle package) has been
nominated in find_busiest_group() in the previous patch.  Use
this information in sched_mc_preferred_wakeup_cpu in function
wake_idle() to bias task wakeups if the following conditions
are satisfied:

        - The present cpu that is trying to wakeup the process is
          idle and waking the target process on this cpu will
          potentially wakeup a completely idle package
        - The previous cpu on which the target process ran is
          also idle and hence selecting the previous cpu may
          wakeup a semi idle cpu package
        - The task being woken up is allowed to run in the
          nominated cpu (cpu affinity and restrictions)

Basically if both the current cpu and the previous cpu on
which the task ran is idle, select the nominated cpu from semi
idle cpu package for running the new task that is waking up.

Cache hotness is considered since the actual biasing happens
in wake_idle() only if the application is cache cold.

This technique will effectively move short running bursty jobs in
a mostly idle system.

Wakeup biasing for power savings gets automatically disabled if
system utilisation increases due to the fact that the probability
of finding both this_cpu and prev_cpu idle decreases.

Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 09:21:52 +01:00
..
irq Merge branch 'irq/sparseirq' into cpus4096 2008-12-17 13:16:08 +01:00
power Merge branch 'sched/core' into cpus4096 2008-12-12 13:48:57 +01:00
time Merge ../linux-2.6-x86 2008-12-13 21:55:51 +10:30
trace Merge ../linux-2.6-x86 2008-12-13 21:55:51 +10:30
.gitignore
Kconfig.freezer container freezer: implement freezer cgroup subsystem 2008-10-20 08:52:34 -07:00
Kconfig.hz sched: fix SCHED_HRTICK dependency 2008-07-28 14:37:38 +02:00
Kconfig.preempt
Makefile Merge branch 'tracing/fastboot' into cpus4096 2008-12-12 12:43:05 +01:00
acct.c tty: Fix abusers of current->sighand->tty 2008-10-13 09:51:42 -07:00
audit.c [PATCH] fix broken timestamps in AVC generated by kernel threads 2008-12-09 02:27:41 -05:00
audit.h
audit_tree.c Fix inotify watch removal/umount races 2008-11-15 12:26:44 -08:00
auditfilter.c Fix inotify watch removal/umount races 2008-11-15 12:26:44 -08:00
auditsc.c [PATCH] fix broken timestamps in AVC generated by kernel threads 2008-12-09 02:27:41 -05:00
backtracetest.c
bounds.c
capability.c security: Fix setting of PF_SUPERPRIV by __capable() 2008-08-14 22:59:43 +10:00
cgroup.c cgroups: fix a race between rmdir and remount 2008-12-15 16:27:07 -08:00
cgroup_debug.c cgroups: fix probable race with put_css_set[_taskexit] and find_css_set 2008-10-20 08:52:38 -07:00
cgroup_freezer.c freezer_cg: disable writing freezer.state of root cgroup 2008-11-12 17:17:16 -08:00
compat.c Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', 'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus 2008-10-20 13:14:06 +02:00
configs.c kernel/configs.c: remove useless comments 2008-10-20 08:52:34 -07:00
cpu.c cpumask: centralize cpu_online_map and cpu_possible_map 2008-12-13 21:19:41 +10:30
cpuset.c cpumask: change cpumask_scnprintf, cpumask_parse_user, cpulist_parse, and cpulist_scnprintf to take pointers. 2008-12-13 21:20:25 +10:30
delayacct.c per-task-delay-accounting: update taskstats for memory reclaim delay 2008-07-25 10:53:47 -07:00
dma-coherent.c dma-coherent: export dma_[alloc|release]_from_coherent methods 2008-08-22 08:34:53 +02:00
dma.c kernel/dma.c: remove a CVS keyword 2008-10-16 11:21:30 -07:00
exec_domain.c proc: move /proc/execdomains to kernel/exec_domain.c 2008-10-23 14:30:41 +04:00
exit.c Merge branches 'sched/core', 'core/core' and 'tracing/core' into cpus4096 2008-11-24 17:46:57 +01:00
extable.c Merge branch 'tracing/fastboot' into cpus4096 2008-12-12 12:43:05 +01:00
fork.c Merge branch 'sched/core' into cpus4096 2008-12-12 13:48:57 +01:00
freezer.c freezer_cg: use thaw_process() in unfreeze_cgroup() 2008-10-30 11:38:45 -07:00
futex.c Merge branches 'core/debug', 'core/futexes', 'core/locking', 'core/rcu', 'core/signal', 'core/urgent' and 'core/xen' into core/core 2008-11-24 17:44:55 +01:00
futex_compat.c
hrtimer.c hrtimer: clean up unused callback modes 2008-11-12 09:54:40 +01:00
itimer.c timers: fix itimer/many thread hang 2008-09-14 16:25:35 +02:00
kallsyms.c sprint_symbol(): use less stack 2008-11-19 18:49:58 -08:00
kexec.c kexec: fix crash_save_vmcoreinfo_init build problem 2008-10-20 15:28:50 -07:00
kfifo.c
kgdb.c kgdb: call touch_softlockup_watchdog on resume 2008-10-06 13:50:59 -05:00
kmod.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus 2008-10-16 12:38:34 -07:00
kprobes.c kernel/kprobes.c: don't pad kretprobe_table_locks[] on uniprocessor builds 2008-11-12 17:17:17 -08:00
ksysfs.c profiling: dynamically enable readprofile at runtime 2008-10-16 11:21:31 -07:00
kthread.c tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() 2008-11-16 09:01:36 +01:00
latencytop.c KSYM_SYMBOL_LEN fixes 2008-12-10 08:01:54 -08:00
lockdep.c Merge branch 'tracing/fastboot' into cpus4096 2008-12-12 12:43:05 +01:00
lockdep_internals.h lockdep: build fix 2008-08-13 12:55:10 +02:00
lockdep_proc.c lockstat: contend with points 2008-10-20 15:43:10 +02:00
marker.c markers/tracpoints: fix non-modular build 2008-11-16 09:52:03 +01:00
module.c tracing/function-graph-tracer: introduce __notrace_funcgraph to filter special functions 2008-12-08 15:11:44 +01:00
mutex-debug.c
mutex-debug.h
mutex.c mutex: __used is needed for function referenced only from inline asm 2008-11-24 10:00:28 +01:00
mutex.h
notifier.c Merge branches 'core/debug', 'core/futexes', 'core/locking', 'core/rcu', 'core/signal', 'core/urgent' and 'core/xen' into core/core 2008-11-24 17:44:55 +01:00
ns_cgroup.c cgroup_clone: use pid of newly created task for new cgroup 2008-07-25 10:53:37 -07:00
nsproxy.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
panic.c taint: add missing comment 2008-12-01 19:55:24 -08:00
params.c Fix compile warning in kernel/params.c 2008-10-23 12:09:00 -07:00
pid.c pidns: remove now unused find_pid function. 2008-07-25 10:53:45 -07:00
pid_namespace.c pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exits 2008-09-02 19:21:38 -07:00
pm_qos_params.c pm_qos_requirement might sleep 2008-09-02 19:21:40 -07:00
posix-cpu-timers.c Merge branch 'sched/core' into cpus4096 2008-12-12 13:48:57 +01:00
posix-timers.c Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2 2008-10-22 09:48:06 +02:00
printk.c printk: remove unused code from kernel/printk.c 2008-10-23 21:54:29 +02:00
profile.c Merge ../linux-2.6-x86 2008-12-13 21:55:51 +10:30
ptrace.c remove __ARCH_WANT_COMPAT_SYS_PTRACE 2008-11-30 11:00:15 -08:00
rcuclassic.c sched: convert nohz_cpu_mask to cpumask_var_t. 2008-11-24 17:51:10 +01:00
rcupdate.c rcupdate: fix bug of rcu_barrier*() 2008-10-21 15:59:53 +02:00
rcupreempt.c byteorder: remove direct includes of linux/byteorder/swab[b].h 2008-10-20 08:52:40 -07:00
rcupreempt_trace.c rcu: trace fix possible mem-leak 2008-08-15 17:54:40 +02:00
rcutorture.c byteorder: remove direct includes of linux/byteorder/swab[b].h 2008-10-20 12:51:53 -07:00
relay.c relayfs: fix infinite loop with splice() 2008-12-10 08:01:52 -08:00
res_counter.c cgroup files: convert res_counter_write() to be a cgroups write_string() handler 2008-07-25 10:53:36 -07:00
resource.c reserve_region_with_split: Fix GFP_KERNEL usage under spinlock 2008-11-01 09:53:58 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c hrtimer: convert kernel/* to the new hrtimer apis 2008-09-05 21:35:13 -07:00
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c sched: nominate preferred wakeup cpu 2008-12-19 09:21:50 +01:00
sched_clock.c Revert "sched_clock: prevent scd->clock from moving backwards" 2008-12-14 16:23:17 -08:00
sched_cpupri.c sched: convert struct cpupri_vec cpumask_var_t. 2008-11-24 17:52:22 +01:00
sched_cpupri.h sched: convert struct cpupri_vec cpumask_var_t. 2008-11-24 17:52:22 +01:00
sched_debug.c sched: add uid information to sched_debug for CONFIG_USER_SCHED 2008-12-01 20:39:50 +01:00
sched_fair.c sched: bias task wakeups to preferred semi-idle packages 2008-12-19 09:21:52 +01:00
sched_features.h sched: backward looking buddy 2008-11-05 10:30:14 +01:00
sched_idletask.c sched: add CONFIG_SMP consistency 2008-10-22 10:01:52 +02:00
sched_rt.c Merge branch 'sched/core' into cpus4096 2008-12-12 13:48:57 +01:00
sched_stats.h Merge ../linux-2.6-x86 2008-12-13 21:55:51 +10:30
seccomp.c
semaphore.c semaphore: __down_common: use signal_pending_state() 2008-08-05 14:33:47 -07:00
signal.c tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() 2008-11-16 09:01:36 +01:00
smp.c generic-ipi: fix the smp_mb() placement 2008-11-06 08:41:56 +01:00
softirq.c irq: call __irq_enter() before calling the tick_idle_check 2008-11-10 22:36:39 +01:00
softlockup.c Merge branch 'sched/core' into cpus4096 2008-12-12 13:48:57 +01:00
spinlock.c lockdep: spin_lock_nest_lock(), checkpatch fixes 2008-08-13 13:56:51 +02:00
srcu.c
stacktrace.c
stop_machine.c stop_machine: fix race with return value (fixes Bug #11989) 2008-11-16 15:09:52 -08:00
sys.c thread_group_cputime: move a couple of callsites outside of ->siglock 2008-11-17 16:55:55 +01:00
sys_ni.c reintroduce accept4 2008-11-19 18:49:57 -08:00
sysctl.c Merge commit 'v2.6.28-rc7' into tracing/core 2008-12-04 09:07:19 +01:00
sysctl_check.c sysctl: check for bogus modes 2008-07-25 10:53:45 -07:00
taskstats.c cpumask: change cpumask_scnprintf, cpumask_parse_user, cpulist_parse, and cpulist_scnprintf to take pointers. 2008-12-13 21:20:25 +10:30
test_kprobes.c
time.c select: add a timespec_add_safe() function 2008-09-05 21:34:57 -07:00
timeconst.pl
timer.c Add round_jiffies_up and related routines 2008-11-06 08:42:48 +01:00
tracepoint.c markers/tracpoints: fix non-modular build 2008-11-16 09:52:03 +01:00
tsacct.c task IO accounting: move all IO statistics in struct task_io_accounting 2008-07-27 16:12:28 -07:00
uid16.c
user.c sched: add uid information to sched_debug for CONFIG_USER_SCHED 2008-12-01 20:39:50 +01:00
user_namespace.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
utsname.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
utsname_sysctl.c sysctl: simplify ->strategy 2008-10-16 11:21:47 -07:00
wait.c wait: kill is_sync_wait() 2008-10-16 11:21:31 -07:00
workqueue.c cpumask: introduce new API, without changing anything 2008-11-06 09:05:33 +01:00