From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x236.google.com (mail-qt0-x236.google.com [IPv6:2607:f8b0:400d:c0d::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 92E093CB41 for ; Fri, 26 Jan 2018 22:31:20 -0500 (EST) Received: by mail-qt0-x236.google.com with SMTP id d54so6200923qtd.4 for ; Fri, 26 Jan 2018 19:31:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to :content-transfer-encoding; bh=3AfL6/0LUvVkl74SZaXERagq6hnYX0/VTXxMN7IXLRo=; b=tSYBB3tRnexGLVmegMTnrOhsivX5/UA8TGrWIVsmFGqndORVvSS4p+VsJU6dHrn28o ysy9mC+mxu11qXDiiADFrvMgQVvuDO9A5+VY0y0N1sxVBrWAoaC798cvkO/jIE/fVbLt 2cOYBEFlTA0ifd59g+TcKQ8Xsvfh9GlT+x4xsj8NIYsB6ouCeCVgrpv0WY4Lw2CSN1iM NpibQZ3zDsSW29kaxme9jKHPM7Enesso4BJW4IwKO4TlWwyPgCwIJAuyZFadLgf0VaXC KkPU9VevYFGHqO1dUHq+R6pg2ksggWjJImkG4946bwW/8FvBLQEkq17/E9pBcGmD03le btWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to :content-transfer-encoding; bh=3AfL6/0LUvVkl74SZaXERagq6hnYX0/VTXxMN7IXLRo=; b=NSF2EmQz4QCDKkwkWynV9anBHZxevAZrZot8RrabAYtcYS0P70xoAdyh2KNF/NUC/q wF399a5G+2reFJ4p2AGYwZ9kPOhWvOemnNYH71Y+TeVr3xUwfBAG67RVPr4LNxTePE+O WKM/YXXw3x+Kdm9gL11WEfOAzEJfYsTNvjT+HmPdYVJLRpAig5mCj97kRuV/WxuhoZXV NkJZt0Hng5VVN2EGxTF85Y/ykwnD1Z/58sL2DvQN40G0jwQC5VIf47wUIVk0snpZng8a i0BNkZ+Iopr1FL+S87shLbN55xw59xD9795VylFN9yd5eG8fBNiAmfuJgRUgPZ6RVpjS KzGg== X-Gm-Message-State: AKwxytcGIQCGJSfmGN1KJAp/9kvxs7NuCOQprOISfBsc5bLyMr8uyrYB 7CMkikuwmpa0H56zh0C+iBeH2l81iB8gq19os91fDQ== X-Google-Smtp-Source: AH8x227QbUYxgrI2arXOEglIGRHgkZ6khvkPBn/0roBsJGR0s8Me+pUUkLwVnTJUZfRC42EInBVmdBtMNVmyxj/bk0E= X-Received: by 10.55.163.131 with SMTP id m125mr23740126qke.299.1517023879963; Fri, 26 Jan 2018 19:31:19 -0800 (PST) MIME-Version: 1.0 Received: by 10.12.168.213 with HTTP; Fri, 26 Jan 2018 19:31:18 -0800 (PST) From: Dave Taht Date: Fri, 26 Jan 2018 19:31:18 -0800 Message-ID: To: bloat Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: [Bloat] 400g Tomahawk-3 chip X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 27 Jan 2018 03:31:20 -0000 If someone could translate the "smart buffering", "flow aware" and "mice v elephants" comments into how it actually works in the tomahawk-3 chip... I'd love it. from: https://www.nextplatform.com/2018/01/20/flattening-networks-budgets-4= 00g-ethernet/ "The packet processing pipeline sits behind the ports, implementing ingress and egress packet processing, and because the buffer is shared, it can hold a lot of data if a port that is the destination becomes clogged and wait out the traffic jam without dropping packets and forcing a resend. The buffer architecture has support for RoCEv2 remote direct memory access and congestion control, and also has what Broadcom calls flow-aware traffic scheduling, which is a key for hyperscalers and cloud builders and more than a few HPC and AI shops, too. =E2=80=9CCompanies are not running monolithic workloads,=E2=80=9D explains = Sankar. =E2=80=9CThey run many different applications, running in parallel, as they= go through the switches. In that case, you have elephants and mice, the former of which causes queueing delays that affect different flows in different ways. So in real time, we can see those bandwidth-consuming elephants and reprioritize them versus the mice to ensure that both classes of traffic are experiencing the least amount of queueing delay. This new architecture for buffering ultimately eliminates drops and has 3X to 5X greater incast absorption and lossless capacity versus alternatives, and in the process it drives down tail latency.=E2=80= =9D --=20 Dave T=C3=A4ht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619