Re: [PATCH 00/10] workqueue: async worker destruction and pool-binding synchronization

Tejun Heo
2014-05-05T15:05:32Z

On Sun, Apr 27, 2014 at 12:08:55PM +0800, Lai Jiangshan wrote:
> Patch1-4: async worker destruction
>
> The old version(https://lkml.org/lkml/2014/2/17/418) code of async worker
> destruction has to dance with pool->lock and worker_idr, it is complicated.
>
> But worker_idr in the new version dosn't requies pool->lock, and the code in
> put_unbound_pool() which waits workers exit is changed to wait on a
> wait_queue_head_t. These two changes make the new async worker destruction
> much simpler.
>
> Patch2 reduces the review burden. It will be easier to review the whole
> patchset if we know destroy_worker() is forced to destroy idle workers only.
>
> ==========
> Patch5-10: pool-binding synchronization and simplify the workers management
>
> The code which binds a worker to the pool and unbind a worker from the pool
> is unfolded in create_worker()/destroy_worker().
> The patchset moves this pool-binding code out and wraps them.
>
> patch3-4 moves the pool-unbinding code out from destroy_worker(), and make
> manger_mutex only protects the pool-unbinding code only rather than
> protects the whole worker-destruction path.
>
> patch5-7 makes manger_mutex only protects the pool-binding code rather than the
> whole worker-creation path.
>
> patch8: rename manger_mutex to bind_mutex
> patch9-10: moves the pool-binding code out from create_worker() and use it for
> rescuer.

Sorry about the late review. I've been pretty sick last week.
Overall, excellent work. We'll prolly go through a couple more
iterations but I really like what's going on.

Thanks a lot!

--
tejun