From patchwork Tue Mar 21 15:03:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arseniy Krasnov X-Patchwork-Id: 13182866 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3DCFC7619A for ; Tue, 21 Mar 2023 15:06:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231207AbjCUPGt (ORCPT ); Tue, 21 Mar 2023 11:06:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229843AbjCUPGq (ORCPT ); Tue, 21 Mar 2023 11:06:46 -0400 Received: from mx.sberdevices.ru (mx.sberdevices.ru [45.89.227.171]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD89A5073E; Tue, 21 Mar 2023 08:06:42 -0700 (PDT) Received: from s-lin-edge02.sberdevices.ru (localhost [127.0.0.1]) by mx.sberdevices.ru (Postfix) with ESMTP id 2F9395FD37; Tue, 21 Mar 2023 18:06:40 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sberdevices.ru; s=mail; t=1679411200; bh=5mxajRLaq47uFRg0ulM6APCp7QX+4bPe7NJQcwr4Nyw=; h=Message-ID:Date:MIME-Version:To:From:Subject:Content-Type; b=T4XVFv0AP7+WUcnHZbSm5woSKZQzeLA3zeL8jBNuql+m18Ega28cRg4X35RZouW+H knq1wyvcfK1ToUU88jzDTvA1EgK9YGNs+XQ/X0seSSxn+HuFuaeslL8Rg5XT4XpKpW caMgeqjbzCF3mPhhxTZzhHBaN6GFBQovtaptyWv+6R27liBRI+ctu5cBppW18QOGsy fDPeHp5k2OYPOK7h4QDbhgh5QyQ9Y175hcfYTNXGv5G+iv6HX14CR4H8om3zxDmNfn /nMM4JmJUWO0m/Xp+qqtN3SLDU21XW9vpLdzHvRhI3C84b53z95KnIcLlfEquE6XV9 OUuvyELGbccng== Received: from S-MS-EXCH01.sberdevices.ru (S-MS-EXCH01.sberdevices.ru [172.16.1.4]) by mx.sberdevices.ru (Postfix) with ESMTP; Tue, 21 Mar 2023 18:06:36 +0300 (MSK) Message-ID: <0e0c1421-7cdc-2582-b120-cad6f42824bb@sberdevices.ru> Date: Tue, 21 Mar 2023 18:03:14 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Content-Language: en-US To: Stefan Hajnoczi , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Bobby Eshleman CC: , , , , , , From: Arseniy Krasnov Subject: [RFC PATCH v4] virtio/vsock: allocate multiple skbuffs on tx X-Originating-IP: [172.16.1.6] X-ClientProxiedBy: S-MS-EXCH02.sberdevices.ru (172.16.1.5) To S-MS-EXCH01.sberdevices.ru (172.16.1.4) X-KSMG-Rule-ID: 4 X-KSMG-Message-Action: clean X-KSMG-AntiSpam-Status: not scanned, disabled by settings X-KSMG-AntiSpam-Interceptor-Info: not scanned X-KSMG-AntiPhishing: not scanned, disabled by settings X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 1.1.2.30, bases: 2023/03/21 07:59:00 #20981652 X-KSMG-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC This adds small optimization for tx path: instead of allocating single skbuff on every call to transport, allocate multiple skbuff's until credit space allows, thus trying to send as much as possible data without return to af_vsock.c. Signed-off-by: Arseniy Krasnov Reviewed-by: Stefano Garzarella --- Link to v1: https://lore.kernel.org/netdev/2c52aa26-8181-d37a-bccd-a86bd3cbc6e1@sberdevices.ru/ Link to v2: https://lore.kernel.org/netdev/ea5725eb-6cb5-cf15-2938-34e335a442fa@sberdevices.ru/ Link to v3: https://lore.kernel.org/netdev/f33ef593-982e-2b3f-0986-6d537a3aaf08@sberdevices.ru/ Changelog: v1 -> v2: - If sent something, return number of bytes sent (even in case of error). Return error only if failed to sent first skbuff. v2 -> v3: - Handle case when transport callback returns unexpected value which is not equal to 'skb->len'. Break loop. - Don't check for zero value of 'rest_len' before calling 'virtio_transport_put_credit()'. Decided to add this check directly to 'virtio_transport_put_credit()' in separate patch. v3 -> v4: - Use WARN_ONCE() to handle case when transport callback returns unexpected value. - Remove useless 'ret = -EFAULT;' assignment for case above. net/vmw_vsock/virtio_transport_common.c | 59 +++++++++++++++++++------ 1 file changed, 45 insertions(+), 14 deletions(-) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 6564192e7f20..a300f25749ea 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -196,7 +196,8 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, const struct virtio_transport *t_ops; struct virtio_vsock_sock *vvs; u32 pkt_len = info->pkt_len; - struct sk_buff *skb; + u32 rest_len; + int ret; info->type = virtio_transport_get_type(sk_vsock(vsk)); @@ -216,10 +217,6 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, vvs = vsk->trans; - /* we can send less than pkt_len bytes */ - if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) - pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE; - /* virtio_transport_get_credit might return less than pkt_len credit */ pkt_len = virtio_transport_get_credit(vvs, pkt_len); @@ -227,17 +224,51 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW) return pkt_len; - skb = virtio_transport_alloc_skb(info, pkt_len, - src_cid, src_port, - dst_cid, dst_port); - if (!skb) { - virtio_transport_put_credit(vvs, pkt_len); - return -ENOMEM; - } + ret = 0; + rest_len = pkt_len; + + do { + struct sk_buff *skb; + size_t skb_len; + + skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE, rest_len); + + skb = virtio_transport_alloc_skb(info, skb_len, + src_cid, src_port, + dst_cid, dst_port); + if (!skb) { + ret = -ENOMEM; + break; + } - virtio_transport_inc_tx_pkt(vvs, skb); + virtio_transport_inc_tx_pkt(vvs, skb); - return t_ops->send_pkt(skb); + ret = t_ops->send_pkt(skb); + + if (ret < 0) + break; + + /* Both virtio and vhost 'send_pkt()' returns 'skb_len', + * but for reliability use 'ret' instead of 'skb_len'. + * Also if partial send happens (e.g. 'ret' != 'skb_len') + * somehow, we break this loop, but account such returned + * value in 'virtio_transport_put_credit()'. + */ + rest_len -= ret; + + if (WARN_ONCE(ret != skb_len, + "'send_pkt()' returns %i, but %zu expected\n", + ret, skb_len)) + break; + } while (rest_len); + + virtio_transport_put_credit(vvs, rest_len); + + /* Return number of bytes, if any data has been sent. */ + if (rest_len != pkt_len) + ret = pkt_len - rest_len; + + return ret; } static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,