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
