From mboxrd@z Thu Jan 1 00:00:00 1970 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 E8C9CC433F5 for ; Wed, 24 Nov 2021 20:24:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230115AbhKXU2G (ORCPT ); Wed, 24 Nov 2021 15:28:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229516AbhKXU2D (ORCPT ); Wed, 24 Nov 2021 15:28:03 -0500 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1874C061574 for ; Wed, 24 Nov 2021 12:24:53 -0800 (PST) Received: by mail-pf1-x435.google.com with SMTP id g19so3722456pfb.8 for ; Wed, 24 Nov 2021 12:24:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=9Yl0DG04mAxYInvrXqkjaY7TbRYAflil46ikhnClhS0=; b=bW5UKkmWFcueYJiHtHAq7pwIiNrz0g0IQlYhDD9r4h0wUnJMi51nTDUdGIbtYro3Kb RLsikSJZWeiTzUxNnqZ9aX/ZsJ8paKQf8DH2sAONVjW950BwMFjVtyUOexv076WTP9+m wCwslGWUGX1PoIkcB/OPMO+e9TjniZnV6FMV4ZE+e3VuiWG1r0ujUm2OK8DvfvuJ0lLK eIymnUaiA/vw+JSM28mnY02N66vDqrOzRLYJ/AGqQmQn7LzQxm8vUc4OmMcmy1orc1uC xi+UvPJD0f5BG65CjFIRde/T7/3v8aynjlMPP5nF/1qym8zJGlILGpwwtS1GKsPaPVck I9Lg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=9Yl0DG04mAxYInvrXqkjaY7TbRYAflil46ikhnClhS0=; b=uCnHi44HoBk81gzPrjx9ezBDY6kirii7YvNNg6NLiagGgf8v29hjOID5wUeOc1WeEA zqisv2jbrlCsXusvrtMaTeReclrt4+Lw7HEClZPmW2c5FnmIfAXEFwDTy9/p38hvYRM/ YJQUFcAcVDF8NdxGeRyVMJCl+qKAa7dSM3lHlp6pIrtCbZ+/EydAKzXqtQL/STU4vZTO Gmf55aonopG/MI1obRuTzhhNoURj6y5qvz7aIW17ZI7p8xpAp1WcBkZC7+ehvsYBUKLt qReoj1R+aijPwTC6ZDNmL8wNku6fmi8VeJAqIro3S9o2euymCeMk+vdaIl8mfnuXNMJu S0xQ== X-Gm-Message-State: AOAM530gK4u1fleMFhcvuciYsRUd1IAxb2xTqncnMELiBK5VzgPf5nqB l3m0VfM/GwUymWiceoeHXIA= X-Google-Smtp-Source: ABdhPJyB4pz1Yd0kl2j69s5xIu2yYG6yexTD969UBMVtU7Ci8FBxrObh8rOBdyKy8EFeAOCIU24QuQ== X-Received: by 2002:a05:6a00:248f:b0:4a0:1e25:3155 with SMTP id c15-20020a056a00248f00b004a01e253155mr9135168pfv.21.1637785493477; Wed, 24 Nov 2021 12:24:53 -0800 (PST) Received: from edumazet1.svl.corp.google.com ([2620:15c:2c4:201:b6ed:6a42:8a10:2f32]) by smtp.gmail.com with ESMTPSA id i10sm472839pjd.3.2021.11.24.12.24.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Nov 2021 12:24:53 -0800 (PST) From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski Cc: netdev , Eric Dumazet , Eric Dumazet Subject: [PATCH net-next 2/2] net: optimize skb_postpull_rcsum() Date: Wed, 24 Nov 2021 12:24:46 -0800 Message-Id: <20211124202446.2917972-3-eric.dumazet@gmail.com> X-Mailer: git-send-email 2.34.0.rc2.393.gf8c9666880-goog In-Reply-To: <20211124202446.2917972-1-eric.dumazet@gmail.com> References: <20211124202446.2917972-1-eric.dumazet@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Dumazet Remove one pair of add/adc instructions and their dependency against carry flag. We can leverage third argument to csum_partial(): X = csum_block_sub(X, csum_partial(start, len, 0), 0); --> X = csum_block_add(X, ~csum_partial(start, len, 0), 0); --> X = ~csum_partial(start, len, ~X); Signed-off-by: Eric Dumazet --- include/linux/skbuff.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index eba256af64a577b458998845f2dc01a5ec80745a..eae4bd3237a41cc1b60b44c91fbfe21dfdd8f117 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3485,7 +3485,11 @@ __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len, static inline void skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len) { - __skb_postpull_rcsum(skb, start, len, 0); + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = ~csum_partial(start, len, ~skb->csum); + else if (skb->ip_summed == CHECKSUM_PARTIAL && + skb_checksum_start_offset(skb) < 0) + skb->ip_summed = CHECKSUM_NONE; } static __always_inline void -- 2.34.0.rc2.393.gf8c9666880-goog