kernel_optimize_test/kernel
Frederic Weisbecker 0a8a2e78b7 timer: Fix bad idle check on irq entry
idle_cpu() is called on irq entry to guess if we need to call
tick_check_idle(). This way we can catch up with jiffies if the tick
was stopped, stop accounting idle time during the interrupt and
maintain the sched clock if it is unstable.

But if we are going to exit the idle loop to schedule a new task (ie:
if we have a task in the runqueue or a remotely enqueued ttwu to
perform), the idle_cpu() check will return 0 such that we miss the
call to tick_check_idle() for all interrupts happening before we
schedule the new task.

As a result these interrupts and the softirqs coming along may deal
with stale jiffies values, bad sched clock values, and won't substract
their time from the idle time accounting.

Fix this with using is_idle_task() instead that strictly checks that
we are running the idle task, without caring about the fact we are
going to schedule a task soon.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/1327427984-23282-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-02-15 15:23:09 +01:00
..
debug module: struct module_ref should contains long fields 2012-01-13 09:32:14 +10:30
events perf: Fix double start/stop in x86_pmu_start() 2012-02-07 16:58:56 +01:00
gcov
irq module_param: make bool parameters really bool (core code) 2012-01-13 09:32:18 +10:30
power PM / Freezer: Thaw only kernel threads if freezing of kernel threads fails 2012-02-04 22:23:05 +01:00
sched sched/rt: Fix task stack corruption under __ARCH_WANT_INTERRUPTS_ON_CTXSW 2012-01-27 12:49:41 +01:00
time nohz: Remove ts->Einidle checks before restarting the tick 2012-02-15 15:23:09 +01:00
trace Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-01-15 11:26:35 -08:00
.gitignore
acct.c
async.c kernel/async: remove redundant declaration. 2012-01-13 09:32:18 +10:30
audit_tree.c
audit_watch.c
audit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit 2012-01-17 16:41:31 -08:00
audit.h audit: remove AUDIT_SETUP_CONTEXT as it isn't used 2012-01-17 16:16:57 -05:00
auditfilter.c audit: allow interfield comparison in audit rules 2012-01-17 16:17:01 -05:00
auditsc.c kernel-doc: fix new warnings in auditsc.c 2012-01-23 08:44:53 -08:00
backtracetest.c
bounds.c
capability.c Revert "capabitlies: ns_capable can use the cap helpers rather than lsm call" 2012-01-17 10:19:41 -08:00
cgroup_freezer.c
cgroup.c
compat.c
configs.c
cpu_pm.c
cpu.c
cpuset.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c sched: Fix ancient race in do_exit() 2012-01-27 11:55:36 +01:00
extable.c
fork.c Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2012-02-11 10:07:11 -08:00
freezer.c
futex_compat.c
futex.c
groups.c
hrtimer.c
hung_task.c
irq_work.c
itimer.c
jump_label.c
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c kdump: crashk_res init check for /sys/kernel/kexec_crash_size 2012-01-12 20:13:11 -08:00
kfifo.c
kmod.c
kprobes.c kprobes: fix a memory leak in function pre_handler_kretprobe() 2012-02-03 16:16:41 -08:00
ksysfs.c
kthread.c
latencytop.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c
Makefile PM: Make sysrq-o be available for CONFIG_PM unset 2012-01-14 00:33:03 +01:00
module.c error: implicit declaration of function 'module_flags_taint' 2012-01-15 16:21:07 -08:00
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
nsproxy.c
padata.c
panic.c panic: don't print redundant backtraces on oops 2012-01-12 20:13:11 -08:00
params.c module: make module param bint handle nul value 2012-02-14 11:02:15 +10:30
pid_namespace.c sysctl: add the kernel.ns_last_pid control 2012-01-12 20:13:11 -08:00
pid.c sysctl: add the kernel.ns_last_pid control 2012-01-12 20:13:11 -08:00
posix-cpu-timers.c
posix-timers.c
printk.c module_param: make bool parameters really bool (core code) 2012-01-13 09:32:18 +10:30
profile.c
ptrace.c Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security 2012-01-14 18:36:33 -08:00
range.c
rcu.h
rcupdate.c
rcutiny_plugin.h
rcutiny.c
rcutorture.c rcu: Add missing __cpuinit annotation in rcutorture code 2012-01-16 09:44:05 -08:00
rcutree_plugin.h
rcutree_trace.c
rcutree.c
rcutree.h
relay.c relay: prevent integer overflow in relay_open() 2012-02-10 09:04:49 +01:00
res_counter.c net: introduce res_counter_charge_nofail() for socket allocations 2012-01-22 15:08:46 -05:00
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
seccomp.c seccomp: audit abnormal end to a process due to seccomp 2012-01-17 16:16:55 -05:00
semaphore.c
signal.c
smp.c
softirq.c timer: Fix bad idle check on irq entry 2012-02-15 15:23:09 +01:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c c/r: prctl: add PR_SET_MM codes to set up mm_struct entries 2012-01-12 20:13:13 -08:00
sysctl_binary.c
sysctl_check.c
sysctl.c
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c
tracepoint.c tracepoints/module: Fix disabling tracepoints with taint CRAP or OOT 2012-01-16 11:35:57 -05:00
tsacct.c
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
wait.c
watchdog.c bugs, x86: Fix printk levels for panic, softlockups and stack dumps 2012-01-26 21:28:45 +01:00
workqueue_sched.h
workqueue.c