Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753978AbYHGTyg (ORCPT ); Thu, 7 Aug 2008 15:54:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752631AbYHGTy2 (ORCPT ); Thu, 7 Aug 2008 15:54:28 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:54650 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752580AbYHGTy1 (ORCPT ); Thu, 7 Aug 2008 15:54:27 -0400 Date: Thu, 7 Aug 2008 20:37:16 +0100 From: Alan Cox To: Joe Peterson Cc: linux-kernel@vger.kernel.org Subject: Re: tty: ctrl-c not always echoed, especially under load Message-ID: <20080807203716.4a9870f6@lxorguk.ukuu.org.uk> In-Reply-To: <489A06D9.1080600@skyrush.com> References: <48977C96.2090005@skyrush.com> <20080805001129.72d06e60@lxorguk.ukuu.org.uk> <489A06D9.1080600@skyrush.com> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; x86_64-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1404 Lines: 37 On Wed, 06 Aug 2008 14:17:29 -0600 Joe Peterson wrote: > Alan Cox wrote: > > If the output buffer is full then echoed characters/^C etc will vanish the > > way n_tty implements its buffering internally. It's always worked that > > way. > > One more observation: > > In Linux, try this: > > # cat > foo > hi^Sthere^Q > ^D > > (in other words, during the cat into "foo", type "hi", hit ^S, then type > "there", then hit ^Q, then, on the next line, ^D to end the file) > > Note that the "there" does not appear after hitting ^Q, but it does > appear in the file. So the characters were accepted, but they were not > echoed (not even saved for echo when the terminal is restarted). > > This behavior differs from that of FreeBSD (just tried it for fun - > haven't tried other Unix's yet). I have noticed other times that the > echo seems to get lost while the tty is stopped. Not sure if all this > is related, but something seems amiss. Thoughts? It should certainly occur if the output buffer is full but that shouldn't be the case for a few bytes. Agreed the current behaviour is unexpected and less than desirable so hack away. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/