From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45C16C43441 for ; Fri, 12 Oct 2018 05:49:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBE0A2087D for ; Fri, 12 Oct 2018 05:49:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EBE0A2087D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727571AbeJLNT7 (ORCPT ); Fri, 12 Oct 2018 09:19:59 -0400 Received: from terminus.zytor.com ([198.137.202.136]:56557 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727286AbeJLNT7 (ORCPT ); Fri, 12 Oct 2018 09:19:59 -0400 Received: from carbon-x1.hos.anvin.org (c-24-5-245-234.hsd1.ca.comcast.net [24.5.245.234] (may be forged)) (authenticated bits=0) by mail.zytor.com (8.15.2/8.15.2) with ESMTPSA id w9C5mv702225361 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Thu, 11 Oct 2018 22:48:58 -0700 Subject: Re: Insanely high baud rates To: "Theodore Y. Ts'o" , Alan Cox , linux-serial@vger.kernel.org, Linux Kernel Mailing List , Greg Kroah-Hartman , Jiri Slaby , Johan Hovold , Alexander Viro References: <3fcef1c1-d746-ae82-c0e6-f079b1a53ffb@zytor.com> <20181010211717.30c1f052@alans-desktop> <16D6AB22-697E-498C-A5B2-3AD90B567E86@zytor.com> <20181011133134.085624af@alans-desktop> <8A583BC1-A295-48D2-B4C3-3E70AA50D035@zytor.com> <20181011214035.GC565@thunk.org> From: "H. Peter Anvin" Message-ID: Date: Thu, 11 Oct 2018 22:48:51 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20181011214035.GC565@thunk.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/11/18 2:40 PM, Theodore Y. Ts'o wrote: > On Thu, Oct 11, 2018 at 07:14:30AM -0700, hpa@zytor.com wrote: >>> >>> I mean - what is the baud rate of a pty ? >> >> Whatever the master wants it to be... > > I think Alan's point is that it is highly unlikely you would be able > to push the equivalent of 4 gbps through a PTY layer. The TTY later > was never engineered for those speeds, and the real question is --- > what's the point? That's what Ethernet is for. > I like to consider the far future; I think things like the Y2038 problem is a good example. Or, as I like to put it, "numbers are cheap, running out of numbers is expensive." Sounds like we have enough of a plan that we aren't completely stuck should it ever become an issue. It might never, of course. -hpa