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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 4D175C6778F for ; Sat, 28 Jul 2018 03:35:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED8C520671 for ; Sat, 28 Jul 2018 03:35:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YeeE2CLV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED8C520671 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.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 S1726090AbeG1E7x (ORCPT ); Sat, 28 Jul 2018 00:59:53 -0400 Received: from mail-it0-f67.google.com ([209.85.214.67]:40121 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725888AbeG1E7x (ORCPT ); Sat, 28 Jul 2018 00:59:53 -0400 Received: by mail-it0-f67.google.com with SMTP id h23-v6so10038390ita.5; Fri, 27 Jul 2018 20:35:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=D3amOF7G+ay6TIFFNc7aL9pg4uX0aWl+AajvVc2IoWI=; b=YeeE2CLVhYL006t16hAZyBF8uj9XPH5sHwxZ13PBh6dPRMD2DPSceUJlt4cUGaCs6s 3suGtXf6EivuOhAmACXUomci0Vzwo+kcvRqCgj+wdKBBvWYtBCh03q3pxab2ZOgCWnZS m+ndHqStZcxoKXyhpYeh2Clo10MlbaHfbaThAr7vPXFua6vol80wU/T+c3GogFY5W2Wv VWokRWoCQMdVD1P6mjaE38y2pH0CEwEFieZQP9OFQUIDPHxwcXyEGLh4dXOX53Kalcr+ NpOh/hT4tePhXcy3I4GUJJaRikwqiaGx75iDOXtlAGnvGcqKfYQSW3OgW4T3xxyzkpml 2M5Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=D3amOF7G+ay6TIFFNc7aL9pg4uX0aWl+AajvVc2IoWI=; b=EP7xBQ7KnBrNOhgJH+GzAii5V72Pk32+SBclor3qhe2K7PPcSBUrcn4egkMKn3FyVc G7fsvMqCxhUkZB4qbS/lzgX1EVnDn//veCoYroxnebbTLqcAYRqbPU6R0XDzCCGarC/d erkD+FLG6llQ7Hp5BideuEzb2gryKVYynX0MZ9+kqH/v71Zia8aEw9XPKlG19y1LLKfY fJGwn7xGq1GMIXHXudXmOUEXDwI6Qaab4P3V4yL6gtJnfyPD5QtWg1FY89jcqr0YMEQz 8+oJFSGmJ9EOL8xNgJ+M+VUBv/JIBYDqCwPZRBADT8D+DaRNsf77yA4EXIusRcbqbZaE NgxQ== X-Gm-Message-State: AOUpUlGcxEq/HqE96pqPCDYXZSALl4drkiUFwSdRbWtSHF51KGJw24iF YqEtnhqXnFwseA9e0MKyFPREhwNBWBQ+COCEdX3Ru7mnusY= X-Google-Smtp-Source: AAOMgpcx374KJPT+p+xG3SZy/8lYzq1b6DohtWip/uVh14nLy5SdwxLwMoM4x02L5q5bSrhfHrRTYuMMh5kxcVulBfs= X-Received: by 2002:a02:13c6:: with SMTP id 189-v6mr8786354jaz.50.1532748903255; Fri, 27 Jul 2018 20:35:03 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a6b:7a47:0:0:0:0:0 with HTTP; Fri, 27 Jul 2018 20:34:22 -0700 (PDT) In-Reply-To: References: <1532746900-11710-1-git-send-email-laoar.shao@gmail.com> From: Yafang Shao Date: Sat, 28 Jul 2018 11:34:22 +0800 Message-ID: Subject: Re: [PATCH net-next 1/2] tcp: call tcp_drop() in tcp collapse To: Eric Dumazet 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 Sat, Jul 28, 2018 at 11:06 AM, Eric Dumazet wrote: > On Fri, Jul 27, 2018 at 8:02 PM Yafang Shao wrote: >> >> When this SKB is dropped, we should add the counter sk_drops. >> That could help us better tracking this behavior. >> >> Signed-off-by: Yafang Shao >> --- >> net/ipv4/tcp_input.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c >> index d51fa35..90f83eb 100644 >> --- a/net/ipv4/tcp_input.c >> +++ b/net/ipv4/tcp_input.c >> @@ -4802,7 +4802,7 @@ static struct sk_buff *tcp_collapse_one(struct sock *sk, struct sk_buff *skb, >> else >> rb_erase(&skb->rbnode, root); >> >> - __kfree_skb(skb); >> + tcp_drop(sk, skb); > > > Absolutely not. > > We do not drop the packet, we have simply lowered the memory overhead. 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 ? Thanks Yafang