From e18e157bb5c8c1cd8a9ba25acfdcf4f3035836f4 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 19 Jul 2023 14:31:09 -0400 Subject: [PATCH] SUNRPC: Send RPC message on TCP with a single sock_sendmsg() call There is now enough infrastructure in place to combine the stream record marker into the biovec array used to send each outgoing RPC message on TCP. The whole message can be more efficiently sent with a single call to sock_sendmsg() using a bio_vec iterator. Note that this also helps with RPC-with-TLS: the TLS implementation can now clearly see where the upper layer message boundaries are. Before, it would send each component of the xdr_buf (record marker, head, page payload, tail) in separate TLS records. Suggested-by: David Howells Reviewed-by: David Howells Signed-off-by: Chuck Lever --- include/linux/sunrpc/svcsock.h | 2 ++ net/sunrpc/svcsock.c | 33 ++++++++++++++++++--------------- 2 files changed, 20 insertions(+), 15 deletions(-) diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h index a711604..caf3308 100644 --- a/include/linux/sunrpc/svcsock.h +++ b/include/linux/sunrpc/svcsock.h @@ -38,6 +38,8 @@ struct svc_sock { /* Number of queued send requests */ atomic_t sk_sendqlen; + struct page_frag_cache sk_frag_cache; + struct completion sk_handshake_done; struct page * sk_pages[RPCSVC_MAXPAGES]; /* received data */ diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 90b1ab9..d4d8160 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1213,31 +1213,30 @@ err_noclose: static int svc_tcp_sendmsg(struct svc_sock *svsk, struct svc_rqst *rqstp, rpc_fraghdr marker, unsigned int *sentp) { - struct kvec rm = { - .iov_base = &marker, - .iov_len = sizeof(marker), - }; struct msghdr msg = { - .msg_flags = MSG_MORE, + .msg_flags = MSG_SPLICE_PAGES, }; unsigned int count; + void *buf; int ret; *sentp = 0; - ret = kernel_sendmsg(svsk->sk_sock, &msg, &rm, 1, rm.iov_len); - if (ret < 0) - return ret; - *sentp += ret; - if (ret != rm.iov_len) - return -EAGAIN; + /* The stream record marker is copied into a temporary page + * fragment buffer so that it can be included in rq_bvec. + */ + buf = page_frag_alloc(&svsk->sk_frag_cache, sizeof(marker), + GFP_KERNEL); + if (!buf) + return -ENOMEM; + memcpy(buf, &marker, sizeof(marker)); + bvec_set_virt(rqstp->rq_bvec, buf, sizeof(marker)); - count = xdr_buf_to_bvec(rqstp->rq_bvec, ARRAY_SIZE(rqstp->rq_bvec), - &rqstp->rq_res); + count = xdr_buf_to_bvec(rqstp->rq_bvec + 1, + ARRAY_SIZE(rqstp->rq_bvec) - 1, &rqstp->rq_res); - msg.msg_flags = MSG_SPLICE_PAGES; iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, - count, rqstp->rq_res.len); + 1 + count, sizeof(marker) + rqstp->rq_res.len); ret = sock_sendmsg(svsk->sk_sock, &msg); if (ret < 0) return ret; @@ -1616,6 +1615,7 @@ static void svc_tcp_sock_detach(struct svc_xprt *xprt) static void svc_sock_free(struct svc_xprt *xprt) { struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + struct page_frag_cache *pfc = &svsk->sk_frag_cache; struct socket *sock = svsk->sk_sock; trace_svcsock_free(svsk, sock); @@ -1625,5 +1625,8 @@ static void svc_sock_free(struct svc_xprt *xprt) sockfd_put(sock); else sock_release(sock); + if (pfc->va) + __page_frag_cache_drain(virt_to_head_page(pfc->va), + pfc->pagecnt_bias); kfree(svsk); } -- 2.7.4