diff options
| author | Chuck Lever <chuck.lever@oracle.com> | 2023-07-19 14:31:29 -0400 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2023-08-29 17:45:22 -0400 |
| commit | 2b877fc53e975bdc5614c0a7d64047cfdbae3894 (patch) | |
| tree | 1b164f42603b3d0de0284044e79b9a1eda5b92da | |
| parent | 89d2d9fbeadcbdbd6302d3d0cd6bfbe219d85b68 (diff) | |
SUNRPC: Reduce thread wake-up rate when receiving large RPC messages
With large NFS WRITE requests on TCP, I measured 5-10 thread wake-
ups to receive each request. This is because the socket layer
calls ->sk_data_ready() frequently, and each call triggers a
thread wake-up. Each recvmsg() seems to pull in less than 100KB.
Have the socket layer hold ->sk_data_ready() calls until the full
incoming message has arrived to reduce the wake-up rate.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
| -rw-r--r-- | net/sunrpc/svcsock.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 8db8227e6c83..2864af3abdca 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1089,6 +1089,9 @@ static void svc_tcp_fragment_received(struct svc_sock *svsk) /* If we have more data, signal svc_xprt_enqueue() to try again */ svsk->sk_tcplen = 0; svsk->sk_marker = xdr_zero; + + smp_wmb(); + tcp_set_rcvlowat(svsk->sk_sk, 1); } /** @@ -1178,10 +1181,17 @@ err_incomplete: goto err_delete; if (len == want) svc_tcp_fragment_received(svsk); - else + else { + /* Avoid more ->sk_data_ready() calls until the rest + * of the message has arrived. This reduces service + * thread wake-ups on large incoming messages. */ + tcp_set_rcvlowat(svsk->sk_sk, + svc_sock_reclen(svsk) - svsk->sk_tcplen); + trace_svcsock_tcp_recv_short(&svsk->sk_xprt, svc_sock_reclen(svsk), svsk->sk_tcplen - sizeof(rpc_fraghdr)); + } goto err_noclose; error: if (len != -EAGAIN) |