From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EF0E12AEE4 for ; Mon, 23 Jun 2025 18:57:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750705024; cv=none; b=ly3KL5YifXXEm9ZldkDmstb64kiFbHtwIJf9EvT13e4QvWPKkrmPh7Svm3KlyLw8HCaq30QxGDWpnBnwjPBhKBdNSdNi55tgbUSEZBfsu03INHt5Am3tTPuZFktn+QBsLFmhBbMLao7e3LidRlTCh7C2fkNhcDvhiDvVsHo3Cm4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750705024; c=relaxed/simple; bh=+lHQELDriFFFgcaQNcJEf1UJGlJsMy19W+PbpdYdtB8=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=OgrJsIKbbuuxoR7I8UKc4wZKPv0wrc0giaxYOkJTOpBBzK8+LA44Fk+6z4gMfiTX0TTNNBduSGngaxFJjI0BNftmzd/oL9lhvJ9jCRMbNpSeK0XJ0fn9cHMcbHFPVGQQHgmrC032aFd52beNJaNVgb1nQNimdHTEUyCaUekFmmI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cv70p9fr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Cv70p9fr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F738C4CEEA; Mon, 23 Jun 2025 18:57:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750705023; bh=+lHQELDriFFFgcaQNcJEf1UJGlJsMy19W+PbpdYdtB8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Cv70p9frwAn24Tkma60VkWeQTH8BJZqwO0C9FR9lTjtW4eyjIVKm2mCHWUDp7vyE1 k6RWlDyUqfD0yygyxg95jYvsqMAgBp0lhMJANZBvjXmgzahrDOK+++uj/WJfmK2okS En37fq/G3tGsJErpyxayHLKTdKfFpzIu0x7zlSCgeKL9uJDimQTM9NctEOQW/huU83 j37UeVbdZnZV/Oc2pkaSuskgD4ozCyJ+ryxTZNz50pzhd+Y/8ZTyziO+Dda7bekQPX wz4XyeFfpPAkaXbc2JqtTkSea8ETpOl0CDCmdFqeSh46Y+HtYJDLUuom9wOQpXrAEj BKbTGRIteikhQ== Date: Mon, 23 Jun 2025 11:57:02 -0700 From: Jakub Kicinski To: "xin.guo" Cc: ncardwell@google.com, netdev@vger.kernel.org Subject: Re: [PATCH net-next] tcp: fix tcp_ofo_queue() to avoid including too much DUP SACK range Message-ID: <20250623115702.76bdd8a2@kernel.org> In-Reply-To: <20250617153706.139462-1-guoxin0309@gmail.com> References: <20250617153706.139462-1-guoxin0309@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 17 Jun 2025 23:37:06 +0800 xin.guo wrote: > If the new coming segment covers more than one skbs in the ofo queue, > and which seq is equal to rcv_nxt , then the sequence range > that is not duplicated will be sent as DUP SACK, the detail as below, > in step6, the {501,2001} range is clearly including too much > DUP SACK range: > 1. client.43629 > server.8080: Flags [.], seq 501:1001, ack 1325288529, > win 20000, length 500: HTTP > 2. server.8080 > client.43629: Flags [.], ack 1, win 65535, options > [nop,nop,TS val 269383721 ecr 200,nop,nop,sack 1 {501:1001}], length 0 > 3. Iclient.43629 > server.8080: Flags [.], seq 1501:2001, > ack 1325288529, win 20000, length 500: HTTP > 4. server.8080 > client.43629: Flags [.], ack 1, win 65535, options > [nop,nop,TS val 269383721 ecr 200,nop,nop,sack 2 {1501:2001} > {501:1001}], length 0 > 5. client.43629 > server.8080: Flags [.], seq 1:2001, > ack 1325288529, win 20000, length 2000: HTTP > 6. server.8080 > client.43629: Flags [.], ack 2001, win 65535, > options [nop,nop,TS val 269383722 ecr 200,nop,nop,sack 1 {501:2001}], > length 0 Looks reasonable, AFAICT, tho perhaps there's some implicit benefit from reporting end of the DSACK == rcv_next.. Could you please add the info about how the packet from step 6 looks "after" this patch? So we have before / after comparison? With that please resend and make sure you include _all_ maintainers that the get_maintainer script points out. You missed CCing Eric D. -- pw-bot: cr