Messages in this thread | | | Subject | Re: [PATCH] powerpc pseries eeh: Convert to kthread API | From | Benjamin Herrenschmidt <> | Date | Tue, 24 Apr 2007 12:42:24 +1000 |
| |
On Mon, 2007-04-23 at 20:08 -0600, Eric W. Biederman wrote: > Benjamin Herrenschmidt <benh@kernel.crashing.org> writes: > > >> 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) > > > > - 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). > > On that note does anyone have a problem is we manage the irq spawning > safe kthreads the same way that we manage the work queue entries. > > i.e. by a structure allocated by the caller?
Not sure... I can see places where I might want to spawn an arbitrary number of these without having to preallocate structures... and if I allocate on the fly, then I need a way to free that structure when the kthread is reaped which I don't think we have currently, do we ? (In fact, I could use that for other things too now that I'm thinking of it ... I might have a go at providing optional kthread destructors).
Ben.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |