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 X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_MED,USER_IN_DEF_DKIM_WL 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 5663EC28CF6 for ; Sat, 28 Jul 2018 03:39:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F100B20841 for ; Sat, 28 Jul 2018 03:39:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WC9nZBLs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F100B20841 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726108AbeG1FDq (ORCPT ); Sat, 28 Jul 2018 01:03:46 -0400 Received: from mail-it0-f67.google.com ([209.85.214.67]:36392 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725905AbeG1FDq (ORCPT ); Sat, 28 Jul 2018 01:03:46 -0400 Received: by mail-it0-f67.google.com with SMTP id p81-v6so10058005itp.1 for ; Fri, 27 Jul 2018 20:38:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=e7U7jWa0eHTJ4xzJcfD190rtQyFi0cyqwK8TMeRGeio=; b=WC9nZBLsQNxRgcR5dogwxP2xN+0FhyTO4aiU6CoV1IVJjfP6vIxmJRP79tyIfW8aXM 3c+ZoDcpv+Q50Vjru1mbBo1qUblSNl2Nu6k468TEPcCprgb7b73ECMBOzZ/BMu1O+NyC Clq+xUTZhZLkeruxDZTRIb+9ViPjmzagjH7FKxrtE+NFE6yZtKWbTBl6d2UbSxdPewG9 VRvo470dxVEamPoVIpCtll+42/REeNMTlsNdiphQTlwMSPk91ja8WhPY6OS6oryZjQkF 8fWecYxqbAlp/Mpx9X7VztNbqNEX8Jdmf7SH3bv9BCXBTGO9uiHhbYhrSu8LOwBipnDB NOog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=e7U7jWa0eHTJ4xzJcfD190rtQyFi0cyqwK8TMeRGeio=; b=A9MdLYZwdRA9Lj3zwAzsv7K7h7775fizzjGzEvuEuWkZLoD6RMlbxy4AJs+2FvZcYM ZVaIHTNAQm6W8/53EXoEo9n7PsuNu3yuKk9j2bLx3tsSv+/dxcBzE6Y6X2VL1Uv0T2ky MMB2rJNNGMtKFdsv0yPoveSVzUF7RTvOqYj/hACrhxlcjxI3EqOdgbIlElJB/1RFBBuQ A5YWyLtmnfMvvnqnWz07WxEVSXnC5dK/oSty/uuK0SJmzcekvxE3hdtqulcBa3eIKOAA e8uuYS7Hhhmk+hixJzcKxTYh5pZJHowPN6p2kPKdxiUjhN+kmvYHAvFkJsdVqNYiFTkJ udBg== X-Gm-Message-State: AOUpUlGS62FYIuCU0+jeZA0Eo4s7dDuLlcFEblwMFY1u8qrEVNdRfhyV tzDov5I62RYxiE94YJfls0HBc9RyDGNl2EdH6aG0Iw== X-Google-Smtp-Source: AAOMgpeFNxLpFPhDjDqQvTg8NCEtH0Kau6T/b8chswvldu4YtTDdsvlU/WsPcdybFX3+ayFx6ftFB7eu5KjqHrhxEfE= X-Received: by 2002:a24:6f0e:: with SMTP id x14-v6mr7750837itb.139.1532749135396; Fri, 27 Jul 2018 20:38:55 -0700 (PDT) MIME-Version: 1.0 References: <1532746900-11710-1-git-send-email-laoar.shao@gmail.com> In-Reply-To: From: Eric Dumazet Date: Fri, 27 Jul 2018 20:38:44 -0700 Message-ID: Subject: Re: [PATCH net-next 1/2] tcp: call tcp_drop() in tcp collapse To: Yafang Shao Cc: David Miller , netdev , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 27, 2018 at 8:35 PM Yafang Shao wrote: > So what about LINUX_MIB_TCPOFOMERGE ? > Regarding LINUX_MIB_TCPOFOMERGE, a skb is already covered by another > skb, is that dropping the packet or simply lowering the memory > overhead ? What do you think ? If you receive two times the same payload, don't you have to drop one of the duplicate ? There is a a big difference between the two cases.