From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: KNI discussion in userspace event Date: Fri, 28 Oct 2016 09:25:25 -0700 Message-ID: <20161028092525.696652d4@xeon-e3> References: <8c7f9d25-b042-6b7e-b197-7873ea7425ef@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: DPDK To: Ferruh Yigit Return-path: Received: from mail-pf0-f175.google.com (mail-pf0-f175.google.com [209.85.192.175]) by dpdk.org (Postfix) with ESMTP id 15DB8532D for ; Fri, 28 Oct 2016 18:25:13 +0200 (CEST) Received: by mail-pf0-f175.google.com with SMTP id s8so39724242pfj.2 for ; Fri, 28 Oct 2016 09:25:12 -0700 (PDT) In-Reply-To: <8c7f9d25-b042-6b7e-b197-7873ea7425ef@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Fri, 28 Oct 2016 15:31:50 +0100 Ferruh Yigit wrote: > Discussed alternatives were: > * Tun/Tap > This won't be as fast as KNI and performance is an issue. That is a myth. Both require the some number of copies. TUN/TAP copies is a syscall and KNI copies is a kthread. Actually, the KNI method is worse because it has kernel thread always running chewing a CPU. I.e it is pure poll mode.