From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262960AbUEBKRf (ORCPT ); Sun, 2 May 2004 06:17:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262961AbUEBKRf (ORCPT ); Sun, 2 May 2004 06:17:35 -0400 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:39951 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S262960AbUEBKRd (ORCPT ); Sun, 2 May 2004 06:17:33 -0400 Date: Sun, 2 May 2004 11:17:29 +0100 From: Russell King To: Andrew Morton , vandrove@vc.cvut.cz, cw@f00f.org, koke@amedias.org, linux-kernel@vger.kernel.org Subject: Re: strange delays on console logouts (tty != 1) Message-ID: <20040502111729.D9605@flint.arm.linux.org.uk> Mail-Followup-To: Andrew Morton , vandrove@vc.cvut.cz, cw@f00f.org, koke@amedias.org, linux-kernel@vger.kernel.org References: <20040430195351.GA1837@amedias.org> <20040501214617.GA6446@taniwha.stupidest.org> <20040501232448.GA4707@vana.vc.cvut.cz> <20040501180347.31f85764.akpm@osdl.org> <20040502090059.A9605@flint.arm.linux.org.uk> <20040502011337.2b0b3ca3.akpm@osdl.org> <20040502091751.B9605@flint.arm.linux.org.uk> <20040502103721.C9605@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20040502103721.C9605@flint.arm.linux.org.uk>; from rmk+lkml@arm.linux.org.uk on Sun, May 02, 2004 at 10:37:21AM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 02, 2004 at 10:37:21AM +0100, Russell King wrote: > On Sun, May 02, 2004 at 09:17:51AM +0100, Russell King wrote: > > > If so, how is tty_hangup() getting involved? > > > > The only way it could be invoked is via SAK, which obviously isn't > > happening here. > > > > However, login _does_ call sys_vhangup() which in turn calls tty_vhangup() > > so I suspect that the statement "tty hangup is scheduled for work_queue" > > is based on the _assumption_ that sys_vhangup() calls tty_hangup() > > rather than the function it actually does. > > Ok, the VT_OPENQRY crap is a debian modification to agetty. As far as > I can see, there is no code in agetty which calls sys_vhangup(). And a further follow-up... Looking in the debian bug system reveals these two bugs: * #216658: getty: opens tty without checking if something else is there, killing keyboard input * #226443: util-linux: [getty] Logout is really long with kernel 2.6 The first one is of particular note, because it is the cause of the GROSS hack in agetty, which according to the comments is also in gdm. I wonder really if the problem was elsewhere, and if Debian wanted to take care of this problem, why they didn't just take the serial line locking solution (really: s/serial line/tty/) and apply it to agetty / gdm. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/ 2.6 Serial core