IB/cq: Don't process more than the given budget

The caller might not want this overhead.
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NYuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/infiniband/core/cq.c

@@ -29,7 +29,13 @@ static int __ib_process_cq(struct ib_cq *cq, int budget)
 {
 	int i, n, completed = 0;
 
-	while ((n = ib_poll_cq(cq, IB_POLL_BATCH, cq->wc)) > 0) {
+	/*
+	 * budget might be (-1) if the caller does not
+	 * want to bound this call, thus we need unsigned
+	 * minimum here.
+	 */
+	while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH,
+			budget - completed), cq->wc)) > 0) {
 		for (i = 0; i < n; i++) {
 			struct ib_wc *wc = &cq->wc[i];