From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f195.google.com (mail-qt0-f195.google.com [209.85.216.195]) by dpdk.org (Postfix) with ESMTP id 084BE2BB0 for ; Wed, 23 Nov 2016 17:49:48 +0100 (CET) Received: by mail-qt0-f195.google.com with SMTP id m48so1091490qta.2 for ; Wed, 23 Nov 2016 08:49:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=lkZbEglQ/f8lCceECKLUNmd6HEZ0Bare2ua76YxWctQ=; b=mQ1LDzRNVw0+e03SWQMtTKDHyt7ncCNmwU1G4b4zTw5xrC0Ib0MxGjg73b7DjvlMHO Lk07fng4bg3b9Psm7PDCVYKLAUpOzMU+ILdWnjgd5JgHCo1wq84AUial1W2q9uzDQ7lB g8OSUfkdFyn9ea3RazpZ8vGnuFmUh0M8K20vuh8uFwyGPSHGjZ2hEoMi3nF+2pTDDUt1 7rrwFQ7n3aVBlJB+7KF8W7KSrLSVgxK5q6S4QitRljiLusfbRZyFk+OF7kmqHc4zE/wP jCD3J41B7p10uHbwLZc3e2Slbv63qxCFddq4UvpueU0jcP1D7+ZzPaMpiENf4XCpPOui xDQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=lkZbEglQ/f8lCceECKLUNmd6HEZ0Bare2ua76YxWctQ=; b=cW4Lq3sAikIPZKY0IN3U8uPo+VmdKPV/b7xUgEpfu6M8xiHC+CT2YEE0kMwGXWL1b1 zNMH5663x7IHe62c0+v4fgniWtTCcihCch5CCIZzEfPpxHxC8lvoaGKLu98WmrfdjYKl Kw/PtvpJAoT14KWHWvB8cuk5q64caI6R1zvbO0ehJOx6KcU9mLtF1c4/HXscoaO0yzJd MTp06xwfiIZmgD+QwZadrBk/sNyT0TFUZ8xU8UMTWa0G3rR1gecRaehKzufqJ6iMIzcf 6fji4ZBcajgjCXuzxl8wFA6ZeH8fvZWksuZ+3KwYfN85VBxKpukD6KfZh8FsiWV6kFKp N4Eg== X-Gm-Message-State: AKaTC03ZK3Uc6ukZPBfpAg842c3VmOxxfX4E/Ma/IlPV74qtQOcEz+lGyK3c4cosWoyBRMmeLJGKH0AIu5zDUg== X-Received: by 10.200.37.76 with SMTP id 12mr3308751qtn.129.1479919787356; Wed, 23 Nov 2016 08:49:47 -0800 (PST) MIME-Version: 1.0 Received: by 10.140.85.244 with HTTP; Wed, 23 Nov 2016 08:49:26 -0800 (PST) In-Reply-To: <20161028092525.696652d4@xeon-e3> References: <8c7f9d25-b042-6b7e-b197-7873ea7425ef@intel.com> <20161028092525.696652d4@xeon-e3> From: Aws Ismail Date: Wed, 23 Nov 2016 11:49:26 -0500 Message-ID: To: Stephen Hemminger Cc: Ferruh Yigit , DPDK Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] KNI discussion in userspace event X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Nov 2016 16:49:48 -0000 Hi Stephen, Ferruh, As an end-user take on this (hence community comment) :), this ties into the rte_eth_tap that Keith sent out and it has been acked and reviewed, So I am trying to see the pros/cons of using this (kni pmd) vs. the tun/tap PMD [1]. Previously, we were using Ferruh's KDP/KCP patches and those served our purpose, but since the KDP/KCP idea has been rejected as yet another set of out-of-tree kernel modules to maintain, it has not gotten much attention since then. We are hoping that tun/tap would be the way to go just because it looks simple and easy to manage from a user app perspective. Having said that, I am not sure what to make of this KNI PMD given Stephen's comments. Could any one comment about the overall direction of which solution to focus on? (tun/tap PMD or KNI pmd)? [1]: http://dpdk.org/dev/patchwork/patch/16566/ (Keith's tun/tap PMD) Thanks. Aws\ On Fri, Oct 28, 2016 at 12:25 PM, Stephen Hemminger < stephen@networkplumber.org> wrote: > 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. >