linux/kernel
Peter Zijlstra 74f5187ac8 sched: Cure load average vs NO_HZ woes
Chase reported that due to us decrementing calc_load_task prematurely
(before the next LOAD_FREQ sample), the load average could be scewed
by as much as the number of CPUs in the machine.

This patch, based on Chase's patch, cures the problem by keeping the
delta of the CPU going into NO_HZ idle separately and folding that in
on the next LOAD_FREQ update.

This restores the balance and we get strict LOAD_FREQ period samples.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chase Douglas <chase.douglas@canonical.com>
LKML-Reference: <1271934490.1776.343.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-23 11:02:02 +02:00
..
gcov
irq Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-04-06 13:03:22 -07:00
power PM / Hibernate: user.c, fix SNAPSHOT_SET_SWAP_AREA handling 2010-04-10 22:28:56 +02:00
time Merge branch 'linus' into sched/core 2010-04-15 09:36:16 +02:00
trace Merge branch 'master' into export-slabh 2010-04-05 11:37:28 +09:00
.gitignore
acct.c copy_signal() cleanup: kill taskstats_tgid_init() and acct_init_pacct() 2010-03-12 15:52:39 -08:00
async.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit_tree.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit_watch.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
audit.h
auditfilter.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
auditsc.c audit: preface audit printk with audit 2010-04-05 13:19:45 -07:00
backtracetest.c
bounds.c kbuild: move bounds.h to include/generated 2009-12-12 13:08:14 +01:00
capability.c sched: Remove remaining USER_SCHED code 2010-04-02 20:12:00 +02:00
cgroup_freezer.c Merge branch 'master' into export-slabh 2010-04-05 11:37:28 +09:00
cgroup.c cgroups: remove duplicate include 2010-03-24 16:31:19 -07:00
compat.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
configs.c
cpu.c Merge branch 'linus' into sched/core 2010-04-15 09:36:16 +02:00
cpuset.c sched: Make select_fallback_rq() cpuset friendly 2010-04-02 20:12:03 +02:00
cred.c Merge branch 'linus' into sched/core 2010-04-15 09:36:16 +02:00
delayacct.c
dma.c
early_res.c x86: Do not free zero sized per cpu areas 2010-03-29 18:55:40 +02:00
elfcore.c elf coredump: add extended numbering support 2010-03-06 11:26:46 -08:00
exec_domain.c
exit.c Merge branch 'linus' into sched/core 2010-04-15 09:36:16 +02:00
extable.c
fork.c mm: avoid null-pointer deref in sync_mm_rss() 2010-04-07 08:38:02 -07:00
freezer.c
futex_compat.c futex: Protect pid lookup in compat code with RCU 2009-12-09 14:22:14 +01:00
futex.c futex: Handle futex value corruption gracefully 2010-02-03 15:13:22 +01:00
groups.c
hrtimer.c hrtimers: Convert to raw_spinlocks 2009-12-14 23:55:34 +01:00
hung_task.c softlockup: Fix hung_task_check_count sysctl 2009-11-27 06:21:57 +01:00
hw_breakpoint.c Merge branch 'perf/core' into perf/urgent 2010-03-04 11:47:52 +01:00
itimer.c itimers: Fix racy writes to cpu_itimer fields 2009-11-18 16:32:12 +01:00
kallsyms.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks mutex: Better control mutex adaptive spinning config 2009-12-03 11:50:11 +01:00
Kconfig.preempt
kexec.c percpu: add __percpu sparse annotations to core kernel subsystems 2010-02-17 11:17:38 +09:00
kfifo.c kfifo: Don't use integer as NULL pointer 2010-02-16 15:11:08 -08:00
kgdb.c kgdb: Turn off tracing while in the debugger 2010-04-02 14:58:19 -05:00
kmod.c kmod: fix resource leak in call_usermodehelper_pipe() 2010-01-11 09:34:04 -08:00
kprobes.c kprobes: Calculate the index correctly when freeing the out-of-line execution slot 2010-03-11 14:06:16 +01:00
ksysfs.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
kthread.c cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node 2010-03-24 16:31:21 -07:00
latencytop.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c Merge branch 'slabh' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc 2010-04-05 09:39:11 -07:00
Makefile elf coredump: replace ELF_CORE_EXTRA_* macros by functions 2010-03-06 11:26:45 -08:00
module.c Fix up possibly racy module refcounting 2010-04-05 19:50:02 -07:00
mutex-debug.c
mutex-debug.h locking: Implement new raw_spinlock 2009-12-14 23:55:32 +01:00
mutex.c mutex: Better control mutex adaptive spinning config 2009-12-03 11:50:11 +01:00
mutex.h
notifier.c sched: Use lockdep-based checking on rcu_dereference() 2010-02-25 10:34:26 +01:00
ns_cgroup.c
nsproxy.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
padata.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
panic.c panic: fix panic_timeout accuracy when running on a hypervisor 2010-03-06 11:26:33 -08:00
params.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-03-12 16:04:50 -08:00
perf_event.c Merge branch 'master' into export-slabh 2010-04-05 11:37:28 +09:00
pid_namespace.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
pid.c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-13 14:43:01 -08:00
pm_qos_params.c
posix-cpu-timers.c Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-26 15:10:38 -07:00
posix-timers.c posix-timers.c: Don't export local functions 2010-02-05 14:54:10 +01:00
printk.c printk: avoid warning when CONFIG_PRINTK is disabled 2010-03-06 11:26:33 -08:00
profile.c
ptrace.c ptrace: Fix ptrace_regset() comments and diagnose errors specifically 2010-02-23 13:45:26 -08:00
range.c x86: Change range end to start+size 2010-02-10 17:47:17 -08:00
rcupdate.c rcu: Make rcu_read_lock_bh_held() allow for disabled BH 2010-03-16 09:57:49 +01:00
rcutiny.c rcu: Eliminate unneeded function wrapping 2009-11-22 18:58:16 +01:00
rcutorture.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2010-03-03 07:34:18 -08:00
rcutree_plugin.h rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU 2010-02-28 09:17:42 +01:00
rcutree_trace.c rcu: Stop overflowing signed integers 2010-02-25 10:34:57 +01:00
rcutree.c rcu: Fix accelerated grace periods for last non-dynticked CPU 2010-02-27 09:53:52 +01:00
rcutree.h rcu: Increase RCU CPU stall timeouts if PROVE_RCU 2010-03-11 13:38:01 +01:00
relay.c splice: comparing unsigned int < 0 2010-03-06 11:26:32 -08:00
res_counter.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
resource.c resources: add interfaces that return conflict information 2010-03-23 13:33:50 -07:00
rtmutex_common.h
rtmutex-debug.c sched: Convert pi_lock to raw_spinlock 2009-12-14 23:55:33 +01:00
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c rtmutes: Convert rtmutex.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
rtmutex.h
rwsem.c
sched_clock.c sched: Fix cpu_clock() in NMIs, on !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK 2009-12-15 09:04:36 +01:00
sched_cpupri.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sched_cpupri.h sched: Convert cpupri lock to raw_spinlock 2009-12-14 23:55:33 +01:00
sched_debug.c Merge branch 'linus' into sched/core 2010-04-15 09:36:16 +02:00
sched_fair.c sched: Add enqueue/dequeue flags 2010-04-02 20:12:05 +02:00
sched_features.h sched: Remove ASYM_GRAN feature 2010-03-11 18:32:53 +01:00
sched_idletask.c sched: Cure load average vs NO_HZ woes 2010-04-23 11:02:02 +02:00
sched_rt.c sched: Add enqueue/dequeue flags 2010-04-02 20:12:05 +02:00
sched_stats.h
sched.c sched: Cure load average vs NO_HZ woes 2010-04-23 11:02:02 +02:00
seccomp.c
semaphore.c
signal.c kernel core: use helpers for rlimits 2010-03-06 11:26:33 -08:00
slow-work-debugfs.c SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
slow-work.c slow-work: use get_ref wrapper instead of directly calling get_ref 2010-03-29 09:13:30 -07:00
slow-work.h SLOW_WORK: CONFIG_SLOW_WORK_PROC should be CONFIG_SLOW_WORK_DEBUG 2010-03-29 09:14:47 -07:00
smp.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
softirq.c hrtimer, softirq: Fix hrtimer->softirq trampoline 2010-02-03 18:17:40 +01:00
softlockup.c softlockup: Stop spurious softlockup messages due to overflow 2010-03-21 19:30:13 +01:00
spinlock.c locking: Cleanup the name space completely 2009-12-14 23:55:33 +01:00
srcu.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
stacktrace.c
stop_machine.c percpu: add __percpu sparse annotations to core kernel subsystems 2010-02-17 11:17:38 +09:00
sys_ni.c Add generic sys_ipc wrapper 2010-03-12 15:52:32 -08:00
sys.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sysctl_binary.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sysctl_check.c ipv4 05/05: add sysctl to accept packets with local source addresses 2009-12-03 12:14:38 -08:00
sysctl.c sysctl extern cleanup: lockdep 2010-03-12 15:53:10 -08:00
taskstats.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
test_kprobes.c
time.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
timeconst.pl
timer.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tracepoint.c
tsacct.c mm: clean up mm_counter 2010-03-06 11:26:23 -08:00
uid16.c
up.c
user_namespace.c
user-return-notifier.c core: Clean up user return notifers use of per_cpu 2009-12-02 10:22:59 +01:00
user.c sched: Remove remaining USER_SCHED code 2010-04-02 20:12:00 +02:00
utsname_sysctl.c sysctl kernel: Remove binary sysctl logic 2009-11-12 02:04:55 -08:00
utsname.c
wait.c
workqueue.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2009-12-10 09:35:44 -08:00