Re: [PATCH] flush_cpu_workqueue: don't flush an empty ->worklist

[Andrew Morton <akpm@osdl.org>]

Just a sad little note that I've utterly lost the plot on the workqueue
changes.

schedule_on_each_cpu-use-preempt_disable.patch
reimplement-flush_workqueue.patch
implement-flush_work.patch
implement-flush_work-sanity.patch
implement-flush_work_keventd.patch
flush_workqueue-use-preempt_disable-to-hold-off-cpu-hotplug.patch
flush_cpu_workqueue-dont-flush-an-empty-worklist.patch
aio-use-flush_work.patch
kblockd-use-flush_work.patch
relayfs-use-flush_keventd_work.patch
tg3-use-flush_keventd_work.patch
e1000-use-flush_keventd_work.patch
libata-use-flush_work.patch
phy-use-flush_work.patch
#bridge-avoid-using-noautorel-workqueues.patch
#
extend-notifier_call_chain-to-count-nr_calls-made.patch
extend-notifier_call_chain-to-count-nr_calls-made-fixes.patch
extend-notifier_call_chain-to-count-nr_calls-made-fixes-2.patch
define-and-use-new-eventscpu_lock_acquire-and-cpu_lock_release.patch
define-and-use-new-eventscpu_lock_acquire-and-cpu_lock_release-fix.patch
eliminate-lock_cpu_hotplug-in-kernel-schedc.patch
eliminate-lock_cpu_hotplug-in-kernel-schedc-fix.patch
handle-cpu_lock_acquire-and-cpu_lock_release-in-workqueue_cpu_callback.patch
fix-flush_workqueue-vs-cpu_dead-race.patch

I don't know which of these are good, bad or indifferent.

Furthermore I don't know which of these need to be tossed overboard if/when
we get around to using the task freezer for CPU hotplug synchronisation. 
Hopefully, a lot of them.  I don't really understand why we're continuing
to struggle with the existing approach before that question is settled.