Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754902AbdDDSE3 (ORCPT ); Tue, 4 Apr 2017 14:04:29 -0400 Received: from mail-qt0-f196.google.com ([209.85.216.196]:34031 "EHLO mail-qt0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932379AbdDDSE0 (ORCPT ); Tue, 4 Apr 2017 14:04:26 -0400 MIME-Version: 1.0 In-Reply-To: <1491328749.7125.66.camel@tzanussi-mobl.amr.corp.intel.com> References: <20170401222119.25106-1-nicolas.pitre@linaro.org> <87pogur0y9.fsf@firstfloor.org> <92fb1e4a-d6df-f55b-c0a1-9c1eb78e3943@longlandclan.id.au> <1491325150.7125.62.camel@tzanussi-mobl.amr.corp.intel.com> <1491328749.7125.66.camel@tzanussi-mobl.amr.corp.intel.com> From: Andy Shevchenko Date: Tue, 4 Apr 2017 21:04:24 +0300 Message-ID: Subject: Re: [PATCH v2 0/5] minitty: a minimal TTY layer alternative for embedded systems To: Tom Zanussi Cc: Geert Uytterhoeven , Stuart Longland , Nicolas Pitre , Andi Kleen , Greg Kroah-Hartman , Jiri Slaby , "linux-serial@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v34I4Xn6022481 Content-Length: 1483 Lines: 39 On Tue, Apr 4, 2017 at 8:59 PM, Tom Zanussi wrote: > On Tue, 2017-04-04 at 20:08 +0300, Andy Shevchenko wrote: >> On Tue, Apr 4, 2017 at 7:59 PM, Tom Zanussi wrote: >> > On Tue, 2017-04-04 at 00:05 +0300, Andy Shevchenko wrote: >> > I was focused at that point mainly on the kernel static size, and using >> > a combination of Josh Triplett's tinification tree, Andi Kleen's LTO and >> > net-diet patches, and my own miscellaneous patches that I was planning >> > on eventually upstreaming, I ended up with a system that I could boot to >> > shell with a 455k text size: >> > >> > Memory: 235636K/245176K available (455K kernel code, 61K rwdata, >> > 64K rodata, 132K init, 56K bss, 3056K reserved, 0K cma-reserved) >> Thanks for sharing your experience. The question closer to this >> discussion what did you do against TTY/UART/(related) layer(s)? >> > > I'd have to go back and take a look, but nothing special AFIAR. > > No patches or hacks along those lines, and the only related thing I see > as far as config is: > > cfg/pty-disable.scc \ > > which maps to: > > # CONFIG_UNIX98_PTYS is not set But on your guestimation how much can we squeeze TTY/UART layer if we do some compile-time configuration? Does it even make sense or better to introduce something like minitty special layer instead? I believe you did some research during time of that project… -- With Best Regards, Andy Shevchenko