Tejun Heo e804ac780e md: fix and update workqueue usage
Workqueue usage in md has two problems.

* Flush can be used during or depended upon by memory reclaim, but md
  uses the system workqueue for flush_work which may lead to deadlock.

* md depends on flush_scheduled_work() to achieve exclusion against
  completion of removal of previous instances.  flush_scheduled_work()
  may incur unexpected amount of delay and is scheduled to be removed.

This patch adds two workqueues to md - md_wq and md_misc_wq.  The
former is guaranteed to make forward progress under memory pressure
and serves flush_work.  The latter serves as the flush domain for
other works.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:32:29 +11:00
..
2010-08-12 04:14:13 +01:00
2010-08-12 04:14:11 +01:00
2010-08-12 04:14:32 +01:00
2010-09-10 20:07:38 +02:00
2010-08-12 04:14:12 +01:00
2010-08-12 04:14:08 +01:00
2010-09-10 12:35:38 +02:00
2010-10-28 17:32:29 +11:00
2010-09-10 12:35:38 +02:00
2010-09-10 12:35:38 +02:00
2010-10-28 17:32:26 +11:00
2010-09-10 12:35:38 +02:00
2010-10-28 17:32:26 +11:00
2010-09-10 12:35:38 +02:00