kernel_optimize_test/kernel
Ingo Molnar d7ea17a769 sched: Fix dynamic power-balancing crash
This crash:

[ 1774.088275] divide error: 0000 [#1] SMP
[ 1774.100355] CPU 13
[ 1774.102498] Modules linked in:
[ 1774.105631] Pid: 30881, comm: hackbench Not tainted 2.6.31-rc8-tip-01308-g484d664-dirty #1629 X8DTN
[ 1774.114807] RIP: 0010:[<ffffffff81041c38>]  [<ffffffff81041c38>]
sched_balance_self+0x19b/0x2d4

Triggers because update_group_power() modifies the sd tree and does
temporary calculations there - not considering that other CPUs
could observe intermediate values, such as the zero initial value.

Calculate it in a temporary variable instead. (we need no memory
barrier as these are all statistical values anyway)

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090904092742.GA11014@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-04 11:52:52 +02:00
..
gcov
irq
power
time
trace
.gitignore
acct.c
async.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cgroup_debug.c
cgroup_freezer.c
cgroup.c
compat.c
configs.c
cpu.c
cpuset.c
cred-internals.h
cred.c
delayacct.c
dma-coherent.c
dma.c
exec_domain.c
exit.c
extable.c
fork.c
freezer.c
futex_compat.c
futex.c
groups.c
hrtimer.c
hung_task.c
itimer.c
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c
kfifo.c
kgdb.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c
Makefile
marker.c
module.c
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
panic.c
params.c
perf_counter.c
pid_namespace.c
pid.c
pm_qos_params.c
posix-cpu-timers.c
posix-timers.c
printk.c
profile.c
ptrace.c
rcuclassic.c
rcupdate.c
rcupreempt_trace.c
rcupreempt.c
rcutorture.c
rcutree_trace.c
rcutree.c
rcutree.h
relay.c
res_counter.c
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c
sched_cpupri.c
sched_cpupri.h
sched_debug.c
sched_fair.c sched: Add wait, sleep and iowait accounting tracepoints 2009-09-02 09:12:18 +02:00
sched_features.h
sched_idletask.c
sched_rt.c sched: Scale down cpu_power due to RT tasks 2009-09-04 10:09:55 +02:00
sched_stats.h
sched.c sched: Fix dynamic power-balancing crash 2009-09-04 11:52:52 +02:00
seccomp.c
semaphore.c
signal.c
slow-work.c
smp.c
softirq.c
softlockup.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c
sysctl_check.c
sysctl.c sched: Scale down cpu_power due to RT tasks 2009-09-04 10:09:55 +02:00
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user.c
utsname_sysctl.c
utsname.c
wait.c
workqueue.c