On Thu, Mar 21, 2013 at 09:35:32AM -0700, Kent Overstreet wrote: > Freeing a kiocb needed to touch the kioctx for three things: > > * Pull it off the reqs_active list > * Decrementing reqs_active > * Issuing a wakeup, if the kioctx was in the process of being freed. > > This patch moves these to aio_complete(), for a couple reasons: > > * aio_complete() already has to issue the wakeup, so if we drop the > kioctx refcount before aio_complete does its wakeup we don't have to > do it twice. > * aio_complete currently has to take the kioctx lock, so it makes sense > for it to pull the kiocb off the reqs_active list too. > * A later patch is going to change reqs_active to include unreaped > completions - this will mean allocating a kiocb doesn't have to look > at the ringbuffer. So taking the decrement of reqs_active out of > kiocb_free() is useful prep work for that patch. > > This doesn't really affect cancellation, since existing (usb) code that > implements a cancel function still calls aio_complete() - we just have > to make sure that aio_complete does the necessary teardown for cancelled > kiocbs. > > It does affect code paths where we free kiocbs that were never > submitted; they need to decrement reqs_active and pull the kiocb off the > reqs_active list. This occurs in two places: kiocb_batch_free(), which > is going away in a later patch, and the error path in io_submit_one. > > Signed-off-by: Kent Overstreet <[email protected]>
Reviewed-by: "Theodore Ts'o" <[email protected]> -- 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/
