On Saturday 29 August 2009, Rafael J. Wysocki wrote: > On Saturday 29 August 2009, Alan Stern wrote: ... > > Strictly speaking, a new thread should be started only when needed. > > That is, only when all the existing threads are busy running a > > callback. It shouldn't be too hard to keep track of when that happens. > > The async framework does that for us. :-) So, when I said "async threads", I should have rather said "async functions", because one async thread can execute multiple functions scheduled with async_schedule(). Taking that into consideration, it all works like this. When there's a new async device to handle and there are no async threads available, a new thread is started and it runs the async function that handles the device and "opportunistically" searches dpm_list (once) for other device that are ready for handling. After this function has returned, the thread goes to sleep and it only exits after being idle for 1 s. In turn, when there's a new async device to handle and there are async threads available, on of them gets the async function to run. I don't really think we can do much better than this in any other approach. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
