Re: [PATCH] powerpc pseries eeh: Convert to kthread API

Benjamin Herrenschmidt [off-list ref] writes:

quoted

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.

quoted

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?

Eric