Peter Zijlstra 866ab43efd sched: Fix the group_imb logic ... On a 2*6*2 machine something like: taskset -c 3-11 bash -c 'for ((i=0;i<9;i++)) do while :; do :; done & done' _should_ result in 9 busy CPUs, each running 1 task. However it didn't quite work reliably, most of the time one cpu of the second socket (6-11) would be idle and one cpu of the first socket (0-5) would have two tasks on it. The group_imb logic is supposed to deal with this and detect when a particular group is imbalanced (like in our case, 0-2 are idle but 3-5 will have 4 tasks on it). The detection phase needed a bit of a tweak as it was too weak and required more than 2 avg weight tasks difference between idle and busy cpus in the group which won't trigger for our test-case. So cure that to be one or more avg task weight difference between cpus. Once the detection phase worked, it was then defeated by the f_b_g() tests trying to avoid ping-pongs. In particular, this_load >= max_load triggered because the pulling cpu (the (first) idle cpu in on the second socket, say 6) would find this_load to be 5 and max_load to be 4 (there'd be 5 tasks running on our socket and only 4 on the other socket). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nikhil Rao <ncrao@google.com> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2011-02-23 11:33:57 +01:00
..
debug	Merge branch 'master' into for-next	2010-12-22 18:57:02 +01:00
gcov	llseek: automatically add .llseek fop	2010-10-15 15:53:27 +02:00
irq	genirq: Prevent irq storm on migration	2011-02-02 22:15:08 +01:00
power	Merge branch 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2011-02-18 12:36:06 -08:00
time	timer debug: Hide kernel addresses via %pK in /proc/timer_list	2011-02-12 14:11:56 +01:00
trace	Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block	2011-02-09 11:45:21 -08:00
.gitignore
acct.c	pass a struct path to vfs_statfs	2010-08-09 16:48:42 -04:00
async.c	async: use workqueue for worker pool	2010-07-14 11:29:46 +02:00
audit_tree.c	in untag_chunk() we need to do alloc_chunk() a bit earlier	2010-10-30 02:18:32 -04:00
audit_watch.c	audit: make functions static	2010-10-30 01:42:19 -04:00
audit.c	audit: error message typo correction	2010-11-03 13:49:58 -04:00
audit.h	audit: make functions static	2010-10-30 01:42:19 -04:00
auditfilter.c	Audit: add support to match lsm labels on user audit messages	2010-10-30 01:41:57 -04:00
auditsc.c	audit mmap	2010-10-30 08:45:43 -04:00
backtracetest.c
bounds.c
capability.c	security: add cred argument to security_capable()	2011-02-11 17:41:58 +11:00
cgroup_freezer.c	cgroup_freezer: update_freezer_state() does incorrect state transitions	2010-10-27 18:03:08 -07:00
cgroup.c	Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin	2011-01-14 09:08:29 -08:00
compat.c	compat: Make compat_alloc_user_space() incorporate the access_ok()	2010-09-14 16:08:45 -07:00
configs.c	llseek: automatically add .llseek fop	2010-10-15 15:53:27 +02:00
cpu.c	Merge branches 'x86-alternatives-for-linus', 'x86-fpu-for-linus', 'x86-hwmon-for-linus', 'x86-paravirt-for-linus', 'core-locking-for-linus' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-01-06 11:11:50 -08:00
cpuset.c	convert cgroup and cpuset	2010-10-29 04:17:06 -04:00
cred.c	CRED: Fix memory and refcount leaks upon security_prepare_creds() failure	2011-02-07 14:04:00 -08:00
delayacct.c
dma.c
elfcore.c
exec_domain.c	sys_personality: remove the bogus checks in sys_personality()->__set_personality() path	2010-08-09 20:45:05 -07:00
exit.c	Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-01-11 11:02:13 -08:00
extable.c
fork.c	thp: khugepaged	2011-01-13 17:32:43 -08:00
freezer.c	Freezer: Fix a race during freezing of TASK_STOPPED tasks	2010-12-24 15:02:40 +01:00
futex_compat.c	futex: Address compiler warnings in exit_robust_list	2010-11-10 13:27:50 +01:00
futex.c	Merge branches 'core-fixes-for-linus', 'x86-fixes-for-linus', 'timers-fixes-for-linus' and 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-01-15 12:45:00 -08:00
groups.c	kernel/groups.c: fix integer overflow in groups_search	2010-09-09 18:57:24 -07:00
hrtimer.c	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-01-13 10:05:56 -08:00
hung_task.c	lockup detector: Fix grammar by adding a missing "to" in the comments	2010-08-17 09:11:52 +02:00
hw_breakpoint.c	perf: Dynamic pmu types	2010-12-16 11:36:43 +01:00
irq_work.c	irq_work: Use per cpu atomics instead of regular atomics	2010-12-18 15:54:48 +01:00
itimer.c
jump_label.c	jump label: Make arch_jump_label_text_poke_early() optional	2010-10-29 12:56:13 -04:00
kallsyms.c	Revert "kernel: make /proc/kallsyms mode 400 to reduce ease of attacking"	2010-11-19 11:54:40 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c	tree-wide: fix comment/printk typos	2010-11-01 15:38:34 -04:00
kfifo.c	kfifo: fix scatterlist usage	2010-10-01 10:50:58 -07:00
kmod.c	Make do_execve() take a const filename pointer	2010-08-17 18:07:43 -07:00
kprobes.c	Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2011-01-07 17:02:58 -08:00
ksysfs.c	sysfs: add struct file* to bin_attr callbacks	2010-05-21 09:37:31 -07:00
kthread.c	sched: Constify function scope static struct sched_param usage	2011-01-07 15:55:45 +01:00
latencytop.c	fs/proc/base.c, kernel/latencytop.c: convert sprintf_symbol() to %ps	2011-01-13 08:03:16 -08:00
lockdep_internals.h	lockdep: No need to disable preemption in debug atomic ops	2010-05-04 05:38:16 +02:00
lockdep_proc.c	locking, lockdep: Convert sprintf_symbol to %pS	2010-11-10 10:23:58 +01:00
lockdep_states.h
lockdep.c	lockdep: Move early boot local IRQ enable/disable status to init/main.c	2011-01-20 13:32:33 +01:00
Makefile	kernel: clean up USE_GENERIC_SMP_HELPERS	2011-01-13 08:03:08 -08:00
module.c	tracepoints: Fix section alignment using pointer array	2011-02-03 09:28:46 -05:00
mutex-debug.c
mutex-debug.h
mutex.c	mutexes, sched: Introduce arch_mutex_cpu_relax()	2010-11-26 15:05:34 +01:00
mutex.h
notifier.c
ns_cgroup.c	cgroup: notify ns_cgroup deprecated	2010-10-27 18:03:09 -07:00
nsproxy.c
padata.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2010-08-04 15:23:14 -07:00
panic.c	ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type support	2011-01-12 03:06:19 -05:00
params.c	module: show version information for built-in modules in sysfs	2011-01-24 14:32:51 +10:30
perf_event.c	perf: Fix reading in perf_event_read()	2011-02-03 12:15:46 +01:00
pid_namespace.c
pid.c	Add RCU check for find_task_by_vpid().	2010-08-19 17:18:02 -07:00
pm_qos_params.c	PM / PM QoS: Fix reversed min and max	2010-11-15 22:45:22 +01:00
posix-cpu-timers.c	posix-cpu-timers: Rcu_read_lock/unlock protect find_task_by_vpid call	2010-11-10 13:07:06 +01:00
posix-timers.c	posix-timers: Annotate lock_timer()	2010-10-21 17:30:06 +02:00
printk.c	cap_syslog: accept CAP_SYS_ADMIN for now	2011-02-10 17:53:55 -08:00
profile.c	llseek: automatically add .llseek fop	2010-10-15 15:53:27 +02:00
ptrace.c	ptrace: use safer wake up on ptrace_detach()	2011-02-11 16:12:19 -08:00
range.c	kernel/range.c: fix clean_sort_range() for the case of full array	2010-11-12 07:55:31 -08:00
rcupdate.c	Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/rcu	2010-10-07 09:43:11 +02:00
rcutiny_plugin.h	rcu: Distinguish between boosting and boosted	2010-11-29 22:01:56 -08:00
rcutiny.c	rcu: avoid pointless blocked-task warnings	2011-01-14 04:58:08 -08:00
rcutorture.c	rcu: add priority-inversion testing to rcutorture	2010-10-07 10:41:08 -07:00
rcutree_plugin.h	rcu: increase synchronize_sched_expedited() batching	2010-12-17 12:34:08 -08:00
rcutree_trace.c	rcu,cleanup: simplify the code when cpu is dying	2010-11-29 22:01:58 -08:00
rcutree.c	Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2011-01-07 17:02:58 -08:00
rcutree.h	rcu: limit rcu_node leaf-level fanout	2010-12-17 12:34:20 -08:00
relay.c	Clean up relay_alloc_page_array() slightly by using vzalloc rather than vmalloc and memset	2010-11-05 08:21:34 -07:00
res_counter.c
resource.c	resources: add arch hook for preventing allocation in reserved areas	2010-12-17 10:01:09 -08:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c	rtmutex-tester: make it build without BKL	2010-10-19 11:29:56 +02:00
rtmutex.c
rtmutex.h
rwsem.c
sched_autogroup.c	sched, autogroup: Fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure	2011-01-18 15:09:42 +01:00
sched_autogroup.h	sched, autogroup: Fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure	2011-01-18 15:09:42 +01:00
sched_clock.c	sched: Add some clock info to sched_debug	2010-11-23 10:29:08 +01:00
sched_cpupri.c	sched: No need for bootmem special cases	2010-07-17 12:06:22 +02:00
sched_cpupri.h	sched: No need for bootmem special cases	2010-07-17 12:06:22 +02:00
sched_debug.c	sched: Use a buddy to implement yield_task_fair()	2011-02-03 14:20:33 +01:00
sched_fair.c	sched: Fix the group_imb logic	2011-02-23 11:33:57 +01:00
sched_features.h	sched: Rewrite tg_shares_up)	2010-11-18 13:27:46 +01:00
sched_idletask.c	sched: Fix switch_from_fair()	2011-01-26 12:33:22 +01:00
sched_rt.c	Merge commit 'v2.6.38-rc5' into sched/core	2011-02-16 13:31:55 +01:00
sched_stats.h	sched_stat: Update sched_info_queue/dequeue() code comments	2010-10-24 13:29:01 +02:00
sched_stoptask.c	sched: Fix switch_from_fair()	2011-01-26 12:33:22 +01:00
sched.c	sched: Add yield_to(task, preempt) functionality	2011-02-03 14:20:33 +01:00
seccomp.c
semaphore.c
signal.c	signals: annotate lock context change on ptrace_stop()	2010-10-27 18:03:12 -07:00
smp.c	Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-01-20 18:30:37 -08:00
softirq.c	softirqs: Free up pf flag PF_KSOFTIRQD	2011-01-26 12:33:20 +01:00
spinlock.c
srcu.c	rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status	2011-01-14 04:56:49 -08:00
stacktrace.c
stop_machine.c	stop_machine: convert cpu notifier to return encapsulate errno value	2010-10-26 16:52:15 -07:00
sys_ni.c	powerpc: define a compat_sys_recv cond_syscall	2010-09-23 17:03:55 +10:00
sys.c	Fix prlimit64 for suid/sgid processes	2011-01-31 13:01:27 +10:00
sysctl_binary.c	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-01-13 10:05:56 -08:00
sysctl_check.c	sysctl: min/max bounds are optional	2010-10-15 14:42:24 -07:00
sysctl.c	Merge commit 'v2.6.38-rc5' into sched/core	2011-02-16 13:31:55 +01:00
taskstats.c	taskstats: use better ifdef for alignment	2011-01-13 08:03:19 -08:00
test_kprobes.c	kprobes: Fix selftest to clear flags field for reusing probes	2010-10-14 08:55:27 +02:00
time.c	time: Add nsecs_to_cputime64 interface for asm-generic	2011-01-26 12:33:20 +01:00
timeconst.pl
timer.c	Revert "lockdep, timer: Fix del_timer_sync() annotation"	2011-02-08 16:18:39 +01:00
tracepoint.c	tracepoints: Fix section alignment using pointer array	2011-02-03 09:28:46 -05:00
tsacct.c	taskstats: use real microsecond granularity for CPU times	2010-10-27 18:03:17 -07:00
uid16.c
up.c
user_namespace.c	user_ns: improve the user_ns on-the-slab packaging	2011-01-13 08:03:18 -08:00
user-return-notifier.c
user.c	fix freeing user_struct in user cache	2010-12-29 11:31:38 -08:00
utsname_sysctl.c
utsname.c
wait.c	docbook: add more wait/wake/completion to device-drivers docbook	2010-10-26 17:32:41 -07:00
watchdog.c	watchdog, nmi: Lower the severity of error messages	2011-02-10 13:21:59 +01:00
workqueue_sched.h	workqueue: implement concurrency managed dynamic worker pool	2010-06-29 10:07:14 +02:00
workqueue.c	workqueue: make sure MAYDAY_INITIAL_TIMEOUT is at least 2 jiffies long	2011-02-16 18:10:19 +01:00