From: Tejun Heo <tj@kernel.org>
To: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: linux-kernel@vger.kernel.org, axboe@kernel.dk, jmoyer@redhat.com,
zab@redhat.com
Subject: Re: [PATCH 14/31] workqueue: replace POOL_MANAGING_WORKERS flag with worker_pool->manager_mutex
Date: Sun, 10 Mar 2013 05:46:32 -0700 [thread overview]
Message-ID: <20130310124632.GF24522@htj.dyndns.org> (raw)
In-Reply-To: <513C5BE2.8090409@cn.fujitsu.com>
Hello, Lai.
On Sun, Mar 10, 2013 at 06:09:38PM +0800, Lai Jiangshan wrote:
> > - if (pool->flags & POOL_MANAGING_WORKERS)
> > + if (!mutex_trylock(&pool->manager_mutex))
> > return ret;
> >
> > - pool->flags |= POOL_MANAGING_WORKERS;
>
>
> if mutex_trylock(&pool->manager_mutex) fails, it does not mean
> the pool is managing workers. (although current code does).
> so I recommend to keep POOL_MANAGING_WORKERS.
So, that's the intention. It's gonna be used during pool destruction
and we want all the workers to think that the pool is being managed
and it's safe to proceed.
> I suggest that you reuse assoc_mutex for your purpose(later patches).
> (and rename assoc_mutex back to manager_mutex)
They are different. assoc_mutex makes the workers wait for the
managership, which shouldn't happen during pool destruction. We want
the workers to assume that the pool is managed which is what
manager_mutex achieves.
Thanks.
--
tejun
next prev parent reply other threads:[~2013-03-10 12:46 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-02 3:23 [PATCHSET wq/for-3.10-tmp] workqueue: implement workqueue with custom worker attributes Tejun Heo
2013-03-02 3:23 ` [PATCH 01/31] workqueue: make sanity checks less punshing using WARN_ON[_ONCE]()s Tejun Heo
2013-03-02 3:23 ` [PATCH 02/31] workqueue: make workqueue_lock irq-safe Tejun Heo
2013-03-02 3:23 ` [PATCH 03/31] workqueue: introduce kmem_cache for pool_workqueues Tejun Heo
2013-03-02 3:23 ` [PATCH 04/31] workqueue: add workqueue_struct->pwqs list Tejun Heo
2013-03-02 3:23 ` [PATCH 05/31] workqueue: replace for_each_pwq_cpu() with for_each_pwq() Tejun Heo
2013-03-02 3:23 ` [PATCH 06/31] workqueue: introduce for_each_pool() Tejun Heo
2013-03-02 3:23 ` [PATCH 07/31] workqueue: restructure pool / pool_workqueue iterations in freeze/thaw functions Tejun Heo
2013-03-10 10:09 ` Lai Jiangshan
2013-03-10 12:34 ` Tejun Heo
2013-03-02 3:23 ` [PATCH 08/31] workqueue: add wokrqueue_struct->maydays list to replace mayday cpu iterators Tejun Heo
2013-03-02 3:24 ` [PATCH 09/31] workqueue: consistently use int for @cpu variables Tejun Heo
2013-03-02 3:24 ` [PATCH 10/31] workqueue: remove workqueue_struct->pool_wq.single Tejun Heo
2013-03-02 3:24 ` [PATCH 11/31] workqueue: replace get_pwq() with explicit per_cpu_ptr() accesses and first_pwq() Tejun Heo
2013-03-02 3:24 ` [PATCH 12/31] workqueue: update synchronization rules on workqueue->pwqs Tejun Heo
2013-03-10 10:09 ` Lai Jiangshan
2013-03-10 12:38 ` Tejun Heo
2013-03-12 18:20 ` [PATCH v2 " Tejun Heo
2013-03-02 3:24 ` [PATCH 13/31] workqueue: update synchronization rules on worker_pool_idr Tejun Heo
2013-03-12 18:20 ` [PATCH v2 " Tejun Heo
2013-03-02 3:24 ` [PATCH 14/31] workqueue: replace POOL_MANAGING_WORKERS flag with worker_pool->manager_mutex Tejun Heo
2013-03-10 10:09 ` Lai Jiangshan
2013-03-10 12:46 ` Tejun Heo [this message]
2013-03-12 18:19 ` [PATCH v2 " Tejun Heo
2013-03-02 3:24 ` [PATCH 15/31] workqueue: separate out init_worker_pool() from init_workqueues() Tejun Heo
2013-03-02 3:24 ` [PATCH 16/31] workqueue: introduce workqueue_attrs Tejun Heo
2013-03-04 18:37 ` [PATCH v2 " Tejun Heo
2013-03-05 22:29 ` Ryan Mallon
2013-03-05 22:33 ` Tejun Heo
2013-03-05 22:34 ` Tejun Heo
2013-03-05 22:40 ` Ryan Mallon
2013-03-05 22:44 ` Tejun Heo
2013-03-05 23:20 ` Ryan Mallon
2013-03-05 23:28 ` Tejun Heo
2013-03-02 3:24 ` [PATCH 17/31] workqueue: implement attribute-based unbound worker_pool management Tejun Heo
2013-03-10 10:08 ` Lai Jiangshan
2013-03-10 12:58 ` Tejun Heo
2013-03-10 18:36 ` Tejun Heo
2013-03-12 18:21 ` [PATCH v2 " Tejun Heo
2013-03-02 3:24 ` [PATCH 18/31] workqueue: remove unbound_std_worker_pools[] and related helpers Tejun Heo
2013-03-02 3:24 ` [PATCH 19/31] workqueue: drop "std" from cpu_std_worker_pools and for_each_std_worker_pool() Tejun Heo
2013-03-02 3:24 ` [PATCH 20/31] workqueue: add pool ID to the names of unbound kworkers Tejun Heo
2013-03-02 3:24 ` [PATCH 21/31] workqueue: drop WQ_RESCUER and test workqueue->rescuer for NULL instead Tejun Heo
2013-03-02 3:24 ` [PATCH 22/31] workqueue: restructure __alloc_workqueue_key() Tejun Heo
2013-03-02 3:24 ` [PATCH 23/31] workqueue: implement get/put_pwq() Tejun Heo
2013-03-02 3:24 ` [PATCH 24/31] workqueue: prepare flush_workqueue() for dynamic creation and destrucion of unbound pool_workqueues Tejun Heo
2013-03-02 3:24 ` [PATCH 25/31] workqueue: perform non-reentrancy test when queueing to unbound workqueues too Tejun Heo
2013-03-02 3:24 ` [PATCH 26/31] workqueue: implement apply_workqueue_attrs() Tejun Heo
2013-03-02 3:24 ` [PATCH 27/31] workqueue: make it clear that WQ_DRAINING is an internal flag Tejun Heo
2013-03-02 3:24 ` [PATCH 28/31] workqueue: reject increasing max_active for ordered workqueues Tejun Heo
2013-03-04 18:30 ` [PATCH UPDATED 28/31] workqueue: reject adjusting max_active or applying attrs to " Tejun Heo
2013-03-02 3:24 ` [PATCH 29/31] cpumask: implement cpumask_parse() Tejun Heo
2013-03-02 3:24 ` [PATCH 30/31] driver/base: implement subsys_virtual_register() Tejun Heo
2013-03-02 18:17 ` Greg Kroah-Hartman
2013-03-02 20:26 ` Tejun Heo
2013-03-03 6:42 ` Kay Sievers
2013-03-05 20:43 ` Tejun Heo
2013-03-07 23:31 ` Greg Kroah-Hartman
2013-03-08 0:04 ` Kay Sievers
2013-03-10 11:57 ` Tejun Heo
2013-03-10 16:45 ` Greg Kroah-Hartman
2013-03-10 17:00 ` Kay Sievers
2013-03-10 17:24 ` Greg Kroah-Hartman
2013-03-10 17:50 ` Kay Sievers
2013-03-10 18:34 ` Tejun Heo
2013-03-12 18:40 ` Tejun Heo
2013-03-02 3:24 ` [PATCH 31/31] workqueue: implement sysfs interface for workqueues Tejun Heo
2013-03-04 18:30 ` [PATCH v2 " Tejun Heo
2013-03-05 20:41 ` [PATCHSET wq/for-3.10-tmp] workqueue: implement workqueue with custom worker attributes Tejun Heo
2013-03-10 10:34 ` Lai Jiangshan
2013-03-10 12:01 ` Tejun Heo
2013-03-11 15:24 ` Tejun Heo
2013-03-11 15:40 ` Lai Jiangshan
2013-03-11 15:42 ` Lai Jiangshan
2013-03-11 15:43 ` Tejun Heo
2013-03-12 18:10 ` Tejun Heo
2013-03-12 18:34 ` Tejun Heo
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