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: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 620be57..1880302 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1005,6 +1005,7 @@
struct sock *sk;
int err;
+restart:
mutex_lock(&transport->recv_mutex);
sk = transport->inet;
if (sk == NULL)
@@ -1018,6 +1019,11 @@
}
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 @@
struct sock *sk;
int err;
+restart:
mutex_lock(&transport->recv_mutex);
sk = transport->inet;
if (sk == NULL)
@@ -1109,6 +1116,11 @@
}
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 @@
.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 @@
}
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);