Re: [PATCH v2] workqueue: doc: Call out the non-reentrance conditions

[Tejun Heo]

On Fri, Oct 22, 2021 at 08:42:08AM +0800, Boqun Feng wrote:
> The current doc of workqueue API suggests that work items are
> non-reentrant: any work item is guaranteed to be executed by at most one
> worker system-wide at any given time. However this is not true, the
> following case can cause a work item W executed by two workers at
> the same time:
> 
>         queue_work_on(0, WQ1, W);
>         // after a worker picks up W and clear the pending bit
>         queue_work_on(1, WQ2, W);
>         // workers on CPU0 and CPU1 will execute W in the same time.
> 
> , which means the non-reentrance of a work item is conditional, and
> Lai Jiangshan provided a nice summary[1] of the conditions, therefore
> use it to describe a work item instance and improve the doc.
> 
> [1]: https://lore.kernel.org/lkml/CAJhGHyDudet_xyNk=8xnuO2==o-u06s0E0GZVP4Q67nmQ84Ceg@xxxxxxxxxxxxxx/
> 
> Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Suggested-by: Tejun Heo <tj@xxxxxxxxxx>
> Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>

Applied to wq/for-5.16.

Thanks.

-- 
tejun