Home
Reading
Searching
Subscribe
Sponsors
Statistics
Posting
Contact
Spam
Lists
Links
About
Hosting
Filtering
Features Download
Marketing
Archives
FAQ
Blog
 
Gmane
From: Tejun Heo <tj <at> kernel.org>
Subject: [PATCHSET wq/for-3.10] workqueue: break up workqueue_lock into multiple locks
Newsgroups: gmane.linux.kernel
Date: Thursday 14th March 2013 02:57:18 UTC (over 3 years ago)
Hello,

Currently, workqueue_lock protects most shared workqueue resources -
the pools, workqueues, pool_workqueues, draining, ID assignments,
mayday handling and so on.  The coverage has grown organically and
there is no identified bottleneck coming from workqueue_lock, but it
has grown a bit too much and scheduled rebinding changes need the
pools and workqueues to be protected by a mutex instead of a spinlock.

The following seven patches break out workqueue_lock into three locks
- wq_mutex, pwq_lock and wq_mayday_lock - so that we get to have a
mutex for pools and workqueues, and the overall locking scheme is
easier to follow.

 0001-workqueue-rename-worker_pool-assoc_mutex-to-manager_.patch
 0002-workqueue-factor-out-initial-worker-creation-into-cr.patch
 0003-workqueue-better-define-locking-rules-around-worker-.patch
 0004-workqueue-relocate-global-variable-defs-and-function.patch
 0005-workqueue-separate-out-pool-and-workqueue-locking-in.patch
 0006-workqueue-separate-out-pool_workqueue-locking-into-p.patch
 0007-workqueue-rename-workqueue_lock-to-wq_mayday_lock.patch

0001-0004 are prep / cleanup patches.

0005 separates out pool and workqueue locking into wq_mutex.

0006 separates out pool_workqueue locking into pwq_lock.

0007 renames workqueue_lock to wq_mayday_lock as that's the only left
user of the lock.

This patchset is on top of

  wq/for-3.10 e626761691 ("workqueue: implement
current_is_workqueue_rescuer()")
+ "workqueue: misc cleanups" patchset [1]

and available in the following git branch.

 git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git
review-finer-locking

diffstat follows.  Thanks.

 kernel/workqueue.c |  355
+++++++++++++++++++++++++++++------------------------
 1 file changed, 195 insertions(+), 160 deletions(-)

--
tejun

[1] http://thread.gmane.org/gmane.linux.kernel/1456511
 
CD: 3ms