Commit c11a3dfd authored Mar 07, 2018 by Julian Wiedmann Committed by Martin Schwidefsky Mar 26, 2018

s390/qdio: restrict buffer merging to eligible devices



Only attempt to merge PENDING into EMPTY buffers for devices where
the PENDING state is actually expected (ie. IQD with CQ).
This might speed up the hot path a little bit.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 0cf1e051

drivers/s390/cio/qdio_main.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -761,7 +761,8 @@ static int get_outbound_buffer_frontier(struct qdio_q *q)
		if (!count)
		goto out;

		count = get_buf_states(q, q->first_to_check, &state, count, 0, 1);
		count = get_buf_states(q, q->first_to_check, &state, count, 0,
		q->u.out.use_cq);
		if (!count)
		goto out;