Re: [PATCH 3/4] workqueue: remove per-node unbound pool when node goes offline.

Lai Jiangshan
2014-12-15T02:02:20Z

On 12/14/2014 12:35 AM, Kamezawa Hiroyuki wrote:
> remove node aware unbound pools if node goes offline.
>
> scan unbound workqueue and remove numa affine pool when
> a node goes offline.
>
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> ---
> kernel/workqueue.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 35f4f00..07b4eb5 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -4921,11 +4921,40 @@ early_initcall(init_workqueues);
> * cached pools per cpu should be freed at node unplug
> */
>
> +/*
> + * Replace per-node pwq with dfl_pwq because this node disappers.
> + * The new pool will be set at CPU_ONLINE by wq_update_unbound_numa.
> + */
> +static void wq_release_unbound_numa(struct workqueue_struct *wq, int nid)
> +{
> + struct pool_workqueue *old_pwq = NULL;
> +
> + if (!wq_numa_enabled || !(wq->flags & WQ_UNBOUND))
> + return;
> + mutex_lock(&wq->mutex);
> + if (wq->unbound_attrs->no_numa)
> + goto out_unlock;
> + spin_lock_irq(&wq->dfl_pwq->pool->lock);
> + get_pwq(wq->dfl_pwq);
> + spin_unlock_irq(&wq->dfl_pwq->pool->lock);
> + old_pwq = numa_pwq_tbl_install(wq, nid, wq->dfl_pwq);
> +out_unlock:
> + mutex_unlock(&wq->mutex);
> + put_pwq_unlocked(old_pwq);
> + return;
> +}

We have already did it in wq_update_unbound_numa().

> +
> void workqueue_register_numanode(int nid)
> {
> }
>
> void workqueue_unregister_numanode(int nid)
> {
> + struct workqueue_struct *wq;
> +
> + mutex_lock(&wq_pool_mutex);
> + list_for_each_entry(wq, &workqueues, list)
> + wq_release_unbound_numa(wq, nid);
> + mutex_unlock(&wq_pool_mutex);
> }
> #endif