From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sender-pp-092.zoho.com (sender-pp-092.zoho.com [135.84.80.237]) by dpdk.org (Postfix) with ESMTP id CA280DED for ; Tue, 28 Aug 2018 19:05:43 +0200 (CEST) ARC-Seal: i=1; a=rsa-sha256; t=1535475940; cv=none; d=zoho.com; s=zohoarc; b=M+F+bolNPohR1MBZWhY+aODqMZNrdi7qiwqVPr7uinb1QyKGVpLIKNlaa9VxsMD9br9W5k7kqB3P7zhf5hMZeDeg6/V362MyRf1e/ZMDkgvBQ69p1w55AumGU7AcTk5kbjjXpdFmPUzTFU4ThXRzCrtdl5H1pDE6FjC5ZIYijAI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1535475940; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:To:ARC-Authentication-Results; bh=MfKJnqYpOjuXZDg4YfzcE7xMVoL0MNB8HSzGUfxlh68=; b=Grvi+z80LwhdIvwQzg6XOLIg0R38tGjxSY/OiKYwkPonrYJn+dPVr4EBn18GEBmhbzMwTzohwakvVcwCM9jnoDNUaOEO/NfiBZspvtHcQbOtBK2LbvfKUhXSoieTgibkk4U/gL920NhKnkDxTsqSRAHy5H+M+ahtOrVM38nDnRU= ARC-Authentication-Results: i=1; mx.zoho.com; dkim=pass header.i=zoho.com; spf=pass smtp.mailfrom=irsaber@zoho.com; dmarc=pass header.from= header.from= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=subject:to:cc:references:from:message-id:date:user-agent:mime-version:in-reply-to:content-type; b=CWZr65VYmKytyH5feMIDKVuFyAHJYquLvzDt4Y/jadDUdOO2caIQniCdZ6XKDmX/o3fWE9REZzWC nndL/1+csbT9qx0pEqQfD6kgezkvUiIvzuVeeb4Ph/+QOfG7YpBf Received: from [192.168.1.8] (188.210.190.126 [188.210.190.126]) by mx.zohomail.com with SMTPS id 1535475938851184.19848951776078; Tue, 28 Aug 2018 10:05:38 -0700 (PDT) To: Stephen Hemminger Cc: dev@dpdk.org References: <74400e6a-91ba-3648-0980-47ceae1089a7@zoho.com> <20180828090142.1262c5ea@shemminger-XPS-13-9360> From: Saber Rezvani Message-ID: Date: Tue, 28 Aug 2018 21:35:33 +0430 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180828090142.1262c5ea@shemminger-XPS-13-9360> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-ZohoMailClient: External Subject: Re: [dpdk-dev] IXGBE throughput loss with 4+ cores X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Aug 2018 17:05:44 -0000 On 08/28/2018 08:31 PM, Stephen Hemminger wrote: > On Tue, 28 Aug 2018 17:34:27 +0430 > Saber Rezvani wrote: > >> Hi, >> >> >> I have run multi_process/symmetric_mp example in DPDK example directory. >> For a one process its throughput is line rate but as I increase the >> number of cores I see decrease in throughput. For example, If the number >> of queues set to 4 and each queue assigns to a single core, then the >> throughput will be something about 9.4. if 8 queues, then throughput >> will be 8.5. >> >> I have read the following, but it was not convincing. >> >> http://mails.dpdk.org/archives/dev/2015-October/024960.html >> >> >> I am eagerly looking forward to hearing from you, all. >> >> >> Best wishes, >> >> Saber >> >> > Not completely surprising. If you have more cores than packet line rate > then the number of packets returned for each call to rx_burst will be less. > With large number of cores, most of the time will be spent doing reads of > PCI registers for no packets! Indeed pktgen says it is generating traffic at line rate, but receiving less than 10 Gb/s. So, it that case there should be something that causes the reduction in throughput :(