From patchwork Fri Mar 31 16:09:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 77845 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp685277vqo; Fri, 31 Mar 2023 09:25:50 -0700 (PDT) X-Google-Smtp-Source: AKy350b1uNBY2MVdMBoCoK7W44cQXBDfDCmp59HW1qBYVKhBrKsNGa6XHNJVgG2LC+FfIb6nfXIY X-Received: by 2002:aa7:dc1a:0:b0:502:7767:3c73 with SMTP id b26-20020aa7dc1a000000b0050277673c73mr3507533edu.22.1680279950142; Fri, 31 Mar 2023 09:25:50 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1680279950; cv=none; d=google.com; s=arc-20160816; b=0hhhFYO+O0AdoqXGOOPhefGrPs2TC6PTroXrqkQDvm0gnC8IDAnVJrPe7UI3SpVyB3 xmieUwBT02idfpYkqf9t86TLZFOLSs2A9zWkxX8vmUU3FMc19JtUCKjIPLk3XncuuaOt RrA+y8L5P65Qj0OIAxr6h6IhBCuJmautGPZH+6sbG7GB+Q/0cqpP5bVvfE3spwKNKZDp RuKsn5FXeStT9YE6n3VRwzpsf3XfwkWiMG8VfKrpDGCfY4pvgOMRrbCZKV/wF9YnQgsm rg2gKwmKEKSWgA5fITUIFyi3z8Lvu92KcuIk700H+W+v+gBZMB85whCgPxMwFOso57tY rzag== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=pMIF11EWm/8cej/KXQhM8DA1wUu2yCmqcuxOX1F+AiY=; b=Mctq03JNQswnBtgOUjNpA1a2Awi61yZ2uHKNLB6DRuKpOFrFbpovSCb34PFCFYRUF/ sGAKp1cr0uqQHCJeNJUyza8UuwTqWoHP8Cx/YDGT4onmJAEy1FA7XG1a23raaFteIORE JjJX0ZxQJUB3LV7L3zOgI6BzXSnWLS1k1m3FbM65Qn2wlrtOrsIr7I/+U0yHuaDL2Zcb bghK4Yeo6gx1yr2RK92IQeW73mNNQh6WUZGACJN5rD87Q/q1thx/mdHM/9edBBB2msSt UDhhMGPdQHHI2LeLyXbea2BN4YosZI9BgCSGtbtSJ/w/aHN9aat9LpRGMEKOI700dxeX TDMQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=A05aVZMF; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id v18-20020aa7dbd2000000b005002e6f0f60si2058939edt.576.2023.03.31.09.25.25; Fri, 31 Mar 2023 09:25:50 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=A05aVZMF; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233527AbjCaQTE (ORCPT + 99 others); Fri, 31 Mar 2023 12:19:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233472AbjCaQR5 (ORCPT ); Fri, 31 Mar 2023 12:17:57 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2C0627839 for ; Fri, 31 Mar 2023 09:12:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1680279096; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pMIF11EWm/8cej/KXQhM8DA1wUu2yCmqcuxOX1F+AiY=; b=A05aVZMFapSVtfyfb3gVBN6B/1XRMMKQJxZBbbzX7wqA1AFG/pHttGlOlr1kleLRFJp5oo f/WW+5UOg9qbujMseFG46zWlypBWGnWQPBlfaZQ+uzFccXb5ANF8+nBSIk9bnHnpsxLKlr KMeB1QsiXsgHagLVDs21nsL47MRMRWU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-237-7dchcmswOjSwjHDFElj0Zg-1; Fri, 31 Mar 2023 12:11:30 -0400 X-MC-Unique: 7dchcmswOjSwjHDFElj0Zg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9D36988904B; Fri, 31 Mar 2023 16:11:28 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id 724AC4020C82; Fri, 31 Mar 2023 16:11:26 +0000 (UTC) From: David Howells To: Matthew Wilcox , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: David Howells , Al Viro , Christoph Hellwig , Jens Axboe , Jeff Layton , Christian Brauner , Chuck Lever III , Linus Torvalds , netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Santosh Shilimkar , linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com Subject: [PATCH v3 46/55] rds: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage Date: Fri, 31 Mar 2023 17:09:05 +0100 Message-Id: <20230331160914.1608208-47-dhowells@redhat.com> In-Reply-To: <20230331160914.1608208-1-dhowells@redhat.com> References: <20230331160914.1608208-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 X-Spam-Status: No, score=-0.2 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1761901229115518835?= X-GMAIL-MSGID: =?utf-8?q?1761901229115518835?= When transmitting data, call down into TCP using a single sendmsg with MSG_SPLICE_PAGES to indicate that content should be spliced rather than performing several sendmsg and sendpage calls to transmit header and data pages. To make this work, the data is assembled in a bio_vec array and attached to a BVEC-type iterator. The header are copied into memory acquired from zcopy_alloc() which just breaks a page up into small pieces that can be freed with put_page(). Signed-off-by: David Howells cc: Santosh Shilimkar cc: "David S. Miller" cc: Eric Dumazet cc: Jakub Kicinski cc: Paolo Abeni cc: Jens Axboe cc: Matthew Wilcox cc: linux-rdma@vger.kernel.org cc: rds-devel@oss.oracle.com cc: netdev@vger.kernel.org --- net/rds/tcp_send.c | 86 +++++++++++++++++++++------------------------- 1 file changed, 40 insertions(+), 46 deletions(-) diff --git a/net/rds/tcp_send.c b/net/rds/tcp_send.c index 8c4d1d6e9249..660d9f203d99 100644 --- a/net/rds/tcp_send.c +++ b/net/rds/tcp_send.c @@ -52,29 +52,24 @@ void rds_tcp_xmit_path_complete(struct rds_conn_path *cp) tcp_sock_set_cork(tc->t_sock->sk, false); } -/* the core send_sem serializes this with other xmit and shutdown */ -static int rds_tcp_sendmsg(struct socket *sock, void *data, unsigned int len) -{ - struct kvec vec = { - .iov_base = data, - .iov_len = len, - }; - struct msghdr msg = { - .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL, - }; - - return kernel_sendmsg(sock, &msg, &vec, 1, vec.iov_len); -} - /* the core send_sem serializes this with other xmit and shutdown */ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm, unsigned int hdr_off, unsigned int sg, unsigned int off) { struct rds_conn_path *cp = rm->m_inc.i_conn_path; struct rds_tcp_connection *tc = cp->cp_transport_data; + struct msghdr msg = { + .msg_flags = MSG_SPLICE_PAGES | MSG_DONTWAIT | MSG_NOSIGNAL, + }; + struct bio_vec *bvec; + unsigned int i, size = 0, ix = 0; + bool free_hdr = false; int done = 0; - int ret = 0; - int more; + int ret = -ENOMEM; + + bvec = kmalloc_array(1 + sg, sizeof(struct bio_vec), GFP_KERNEL); + if (!bvec) + goto out; if (hdr_off == 0) { /* @@ -99,43 +94,37 @@ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm, if (hdr_off < sizeof(struct rds_header)) { /* see rds_tcp_write_space() */ + void *p; + set_bit(SOCK_NOSPACE, &tc->t_sock->sk->sk_socket->flags); - ret = rds_tcp_sendmsg(tc->t_sock, - (void *)&rm->m_inc.i_hdr + hdr_off, - sizeof(rm->m_inc.i_hdr) - hdr_off); - if (ret < 0) - goto out; - done += ret; - if (hdr_off + done != sizeof(struct rds_header)) + ret = -ENOMEM; + p = page_frag_memdup(NULL, + (void *)&rm->m_inc.i_hdr + hdr_off, + sizeof(rm->m_inc.i_hdr) - hdr_off, + GFP_KERNEL, ULONG_MAX); + if (!p) goto out; + bvec_set_virt(&bvec[ix], p, sizeof(rm->m_inc.i_hdr) - hdr_off); + free_hdr = true; + size += bvec[ix].bv_len; + ix++; } - more = rm->data.op_nents > 1 ? (MSG_MORE | MSG_SENDPAGE_NOTLAST) : 0; - while (sg < rm->data.op_nents) { - int flags = MSG_DONTWAIT | MSG_NOSIGNAL | more; - - ret = tc->t_sock->ops->sendpage(tc->t_sock, - sg_page(&rm->data.op_sg[sg]), - rm->data.op_sg[sg].offset + off, - rm->data.op_sg[sg].length - off, - flags); - rdsdebug("tcp sendpage %p:%u:%u ret %d\n", (void *)sg_page(&rm->data.op_sg[sg]), - rm->data.op_sg[sg].offset + off, rm->data.op_sg[sg].length - off, - ret); - if (ret <= 0) - break; - - off += ret; - done += ret; - if (off == rm->data.op_sg[sg].length) { - off = 0; - sg++; - } - if (sg == rm->data.op_nents - 1) - more = 0; + for (i = sg; i < rm->data.op_nents; i++) { + bvec_set_page(&bvec[ix], + sg_page(&rm->data.op_sg[i]), + rm->data.op_sg[i].length - off, + rm->data.op_sg[i].offset + off); + off = 0; + size += bvec[ix].bv_len; + ix++; } + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, bvec, ix, size); + ret = sock_sendmsg(tc->t_sock, &msg); + rdsdebug("tcp sendmsg-splice %u,%u ret %d\n", ix, size, ret); + out: if (ret <= 0) { /* write_space will hit after EAGAIN, all else fatal */ @@ -158,6 +147,11 @@ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm, } if (done == 0) done = ret; + if (bvec) { + if (free_hdr) + put_page(bvec[0].bv_page); + kfree(bvec); + } return done; }