From patchwork Wed Mar 10 08:28:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunsheng Lin X-Patchwork-Id: 12127269 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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3707C433E0 for ; Wed, 10 Mar 2021 08:29:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9595B64FDE for ; Wed, 10 Mar 2021 08:29:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232191AbhCJI2m (ORCPT ); Wed, 10 Mar 2021 03:28:42 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:13080 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230156AbhCJI23 (ORCPT ); Wed, 10 Mar 2021 03:28:29 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4DwQC23BPhzMknJ; Wed, 10 Mar 2021 16:26:06 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.498.0; Wed, 10 Mar 2021 16:28:14 +0800 From: l00371289 To: , CC: , , , , , , , Subject: [PATCH net-next] skbuff: remove some unnecessary operation in skb_segment_list() Date: Wed, 10 Mar 2021 16:28:58 +0800 Message-ID: <1615364938-52943-1-git-send-email-linyunsheng@huawei.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 X-Originating-IP: [10.69.192.56] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Yunsheng Lin gro list uses skb_shinfo(skb)->frag_list to link two skb together, and NAPI_GRO_CB(p)->last->next is used when there are more skb, see skb_gro_receive_list(). gso expects that each segmented skb is linked together using skb->next, so only the first skb->next need to set to skb_shinfo(skb)-> frag_list when doing gso list segment. It is the same reason that nskb->next does not need to be set to list_skb before goto the error handling, because nskb->next already pointers to list_skb. And nskb is also the last skb at the end of loop, so remove tail variable and use nskb instead. Signed-off-by: Yunsheng Lin --- net/core/skbuff.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index c421c8f..e8320b5 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3732,13 +3732,13 @@ struct sk_buff *skb_segment_list(struct sk_buff *skb, unsigned int tnl_hlen = skb_tnl_header_len(skb); unsigned int delta_truesize = 0; unsigned int delta_len = 0; - struct sk_buff *tail = NULL; struct sk_buff *nskb, *tmp; int err; skb_push(skb, -skb_network_offset(skb) + offset); skb_shinfo(skb)->frag_list = NULL; + skb->next = list_skb; do { nskb = list_skb; @@ -3756,17 +3756,8 @@ struct sk_buff *skb_segment_list(struct sk_buff *skb, } } - if (!tail) - skb->next = nskb; - else - tail->next = nskb; - - if (unlikely(err)) { - nskb->next = list_skb; + if (unlikely(err)) goto err_linearize; - } - - tail = nskb; delta_len += nskb->len; delta_truesize += nskb->truesize; @@ -3793,7 +3784,7 @@ struct sk_buff *skb_segment_list(struct sk_buff *skb, skb_gso_reset(skb); - skb->prev = tail; + skb->prev = nskb; if (skb_needs_linearize(skb, features) && __skb_linearize(skb))