On Mon, 13 Aug 2007, Rafael J. Wysocki wrote: > On Sunday, 12 August 2007 10:11, Stefan Richter wrote: > > In which situations is create_freezeable_workqueue() to be preferred > > over create_singlethread_workqueue()? > > > > Is a freezable worqueue preferable whenever the worker thread /can/ be > > frozen, or is it only to be used if the thread /must/ be frozen during > > suspend? > > The latter, IMO. > > Generally, if you want it to be frozen.
A good example of a reason for making a workqueue freezable is that the workqueue contains entries which would cause a suspended device to be resumed. Obviously you don't want such things to happen while the system is going to sleep. A little less obviously, there might also be problems if such a routine ran while the system was waking up. Another reason might be that the workqueue contains entries which would try to register or unregister a device. Such actions aren't a good idea at times when the PM core is iterating through a list of all devices in order to suspend or resume them. And in the future such actions may block, effectively freezing the workqueue anyway -- which could be troublesome if you don't want the workqueue to be frozen! Alan Stern - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
