Commit 0af3442a authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Add explicit rescheduling points in the receive path 



When reading the reply from the server, insert an explicit
cond_resched() to avoid starving higher priority tasks.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 3d188805

net/sunrpc/xprtsock.c

+19 −2
Original line number Diff line number Diff line
@@ -1005,6 +1005,7 @@ static void xs_local_data_receive(struct sock_xprt *transport) 
	struct sock *sk;

	int err;



restart:

	mutex_lock(&transport->recv_mutex);

	sk = transport->inet;

	if (sk == NULL)
@@ -1018,6 +1019,11 @@ static void xs_local_data_receive(struct sock_xprt *transport) 
		}

		if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))

			break;

		if (need_resched()) {

			mutex_unlock(&transport->recv_mutex);

			cond_resched();

			goto restart;

		}

	}

out:

	mutex_unlock(&transport->recv_mutex);
@@ -1096,6 +1102,7 @@ static void xs_udp_data_receive(struct sock_xprt *transport) 
	struct sock *sk;

	int err;



restart:

	mutex_lock(&transport->recv_mutex);

	sk = transport->inet;

	if (sk == NULL)
@@ -1109,6 +1116,11 @@ static void xs_udp_data_receive(struct sock_xprt *transport) 
		}

		if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))

			break;

		if (need_resched()) {

			mutex_unlock(&transport->recv_mutex);

			cond_resched();

			goto restart;

		}

	}

out:

	mutex_unlock(&transport->recv_mutex);
@@ -1528,16 +1540,16 @@ static void xs_tcp_data_receive(struct sock_xprt *transport) 
		.arg.data = xprt,

	};

	unsigned long total = 0;

	int loop;

	int read = 0;



restart:

	mutex_lock(&transport->recv_mutex);

	sk = transport->inet;

	if (sk == NULL)

		goto out;



	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */

	for (loop = 0; loop < 64; loop++) {

	for (;;) {

		rd_desc.count = RPC_TCP_READ_CHUNK_SZ;

		lock_sock(sk);

		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
@@ -1548,6 +1560,11 @@ static void xs_tcp_data_receive(struct sock_xprt *transport) 
		}

		release_sock(sk);

		total += read;

		if (need_resched()) {

			mutex_unlock(&transport->recv_mutex);

			cond_resched();

			goto restart;

		}

	}

	if (test_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))

		queue_work(xprtiod_workqueue, &transport->recv_worker);