On Mon, Feb 17, 2014 at 09:29:34PM -0500, Peter Hurley wrote: > >It never would have occurred to me that you could safely change the > >function for a work item that is already scheduled or running. > >Especially given that PREPARE_WORK() is just a simple assignment (i.e. > >no serialisation). > > process_one_work() has an established order that safely allows for > resetting the work function and scheduling the work, and further > guaranteeing that the new work function will run. > > Further, existing memory barriers ensure that > 1. The new work function is visible on all cpus before testing if > the work is already pending. > 2. The new work function is stored as the worker's current function > before the work is marked as not pending. > > If this wasn't possible, then single-threaded workqueues could > not be used for multiple functions without flushing work. > > I wonder if the floppy driver is broken too.
Ugh... I'd just rather remove PREPARE_WORK altogether. It's a pretty dumb thing to do anyway. I'll look into it. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
