android_kernel_samsung_msm8976/include
Tejun Heo 3a101d0548 sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining
Currently, when a cpu goes down, cpu_active is cleared before
CPU_DOWN_PREPARE starts and cpuset configuration is updated from a
default priority cpu notifier.  When a cpu is coming up, it's set
before CPU_ONLINE but cpuset configuration again is updated from the
same cpu notifier.

For cpu notifiers, this presents an inconsistent state.  Threads which
a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be
migrated to other cpus because the cpu is no more inactive.

Fix it by updating cpu_active in the highest priority cpu notifier and
cpuset configuration in the second highest when a cpu is coming up.
Down path is updated similarly.  This guarantees that all other cpu
notifiers see consistent cpu_active and cpuset configuration.

cpuset_track_online_cpus() notifier is converted to
cpuset_update_active_cpus() which just updates the configuration and
now called from cpuset_cpu_[in]active() notifiers registered from
sched_init_smp().  If cpuset is disabled, cpuset_update_active_cpus()
degenerates into partition_sched_domains() making separate notifier
for !CONFIG_CPUSETS unnecessary.

This problem is triggered by cmwq.  During CPU_DOWN_PREPARE, hotplug
callback creates a kthread and kthread_bind()s it to the target cpu,
and the thread is expected to run on that cpu.

* Ingo's test discovered __cpuinit/exit markups were incorrect.
  Fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Menage <menage@google.com>
2010-06-08 21:40:36 +02:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2010-05-28 14:42:18 -07:00
asm-generic Merge branch 'for-35' of git://repo.or.cz/linux-kbuild 2010-06-01 08:55:52 -07:00
crypto
drm Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2010-06-03 07:19:45 -07:00
keys
linux sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining 2010-06-08 21:40:36 +02:00
math-emu
media V4L/DVB: saa7134: add RM-K6 remote control support for Avermedia M135A 2010-06-01 01:22:09 -03:00
mtd
net net: check for refcount if pop a stacked dst_entry 2010-06-04 15:56:00 -07:00
pcmcia
rdma IB/core: Allow device-specific per-port sysfs files 2010-05-21 10:34:44 -07:00
rxrpc
scsi SCSI: implement sd_unlock_native_capacity() 2010-06-02 13:50:04 -04:00
sound Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 2010-05-20 09:41:44 -07:00
trace Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-06-03 15:47:51 -07:00
video fbdev: move FBIO_WAITFORVSYNC to linux/fb.h 2010-05-25 08:07:09 -07:00
xen
Kbuild