Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755223AbYHYSDi (ORCPT ); Mon, 25 Aug 2008 14:03:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756636AbYHYSDZ (ORCPT ); Mon, 25 Aug 2008 14:03:25 -0400 Received: from shadow.wildlava.net ([67.40.138.81]:60642 "EHLO shadow.wildlava.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756615AbYHYSDY (ORCPT ); Mon, 25 Aug 2008 14:03:24 -0400 Message-ID: <48B2F3E9.5020804@skyrush.com> Date: Mon, 25 Aug 2008 12:03:21 -0600 From: Joe Peterson User-Agent: Thunderbird 2.0.0.16 (X11/20080727) MIME-Version: 1.0 To: David Newall CC: Willy Tarreau , Chris Frey , Vegard Nossum , linux-kernel@vger.kernel.org Subject: Re: Visible Ctrl-C in latest kernels References: <20080822201537.GA18242@foursquare.net> <19f34abd0808230253w663722dcwde1303998e194ddf@mail.gmail.com> <48B04E42.3030405@skyrush.com> <20080824010231.GA26030@foursquare.net> <20080825122024.GA19337@1wt.eu> <48B2EDC2.1020608@davidnewall.com> In-Reply-To: <48B2EDC2.1020608@davidnewall.com> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2121 Lines: 51 David Newall wrote: > Willy Tarreau wrote: >> I would not be surprized that it is what has caused delays for Ctrl-C >> to take effect for some of us. As discussed in another thread on the >> subject, the problem was relatively recent and not easy to reproduce. >> > > I don't think so. Joe Peterson raised A line of enquiry, which looked > quite promising to me, in > http://marc.info/?l=linux-kernel&m=121502197008293. He observed weird > behaviour with pgrp, and that doesn't seem to have been explored > adequately. I think it's worth highlighting that the code which sends > the signal is the following snippet, from n_tty.c: > > if (tty->pgrp) > kill_pgrp(tty->pgrp, signal, 1); > > > I wonder if pgrp has a value different than we expect? David, Subsequently, I determined that the issue I talked about in the above referenced thread was a bug in bash. Here is my post about this: http://marc.info/?l=linux-kernel&m=121537020432289&w=2 The bash author has developed a simple patch, and it should appear (according to him) in the new bash version. > I had an idea; it didn't work out as I expected, but it did produce a > result that I can't immediately explain; and it might be relevant. The > following program, when executed in background (./testprogram &) stops > at tcsetpgrp(), which is fine; and if then continued (fg), it is immune > to the interrupt, quit and suspend keys. However, it is not immune to > those keys if executed in foreground (./testprogram). As said, I can't > immediately explain this, and it seems like it might be important... When I run your program, foreground or background, it always completes (i.e. 5 "." chars) - i.e., I cannot interrupt it before it finishes. This seems different than what you see. Given the nature of the bash issue, it does not seem related, at least not directly. -Joe -- 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/