xprtrdma: Optimize rpcrdma_post_recvs()

Micro-optimization: In rpcrdma_post_recvs, since commit e340c2d6ef2a
("xprtrdma: Reduce the doorbell rate (Receive)"), the common case is
to return without doing anything. Found with perf.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index db90083..ac2abf4 100644 (file)
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1465,7 +1465,7 @@ rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
        count = 0;
 
        needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1);
-       if (ep->rep_receive_count > needed)
+       if (likely(ep->rep_receive_count > needed))
                goto out;
        needed -= ep->rep_receive_count;
        if (!temp)