On Tue, Apr 24, 2007 at 11:38:53AM +1000, Benjamin Herrenschmidt wrote: > > The only reason for using threads here is to get the error recovery > > out of an interrupt context (where errors may be detected), and then, > > an hour later, decrement a counter (which is how we limit these to > > 6 per hour). Thread reaping is "trivial", the thread just exits > > after an hour. > > In addition, it should be a thread and not done from within keventd > because : > > - It can take a long time (well, relatively but still too long for a > work queue) Uhh, 15 or 20 seconds even. That's a long time by any kernel standard. > - The driver callbacks might need to use keventd or do flush_workqueue > to synchronize with their own workqueues when doing an internal > recovery. > > > Since these are events rare, I've no particular concern about > > performance or resource consumption. The current code seems > > to work just fine. :-) > > I think moving to kthread's is cleaner (just a wrapper around kernel > threads that simplify dealing with reaping them out mostly) and I agree > with Christoph that it would be nice to be able to "fire off" kthreads > from interrupt context.. in many cases, we abuse work queues for things > that should really done from kthreads instead (basically anything that > takes more than a couple hundred microsecs or so). It would be nice to have threads that can be "fired off" from an interrupt context. That would simplify the EEH code slightly (removing a few dozen lines of code that do this bounce). I presume that various device drivers might find this useful as well. --linas - To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
