From owner-freebsd-stable@FreeBSD.ORG Mon Nov 26 22:30:08 2007 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8664116A46D; Mon, 26 Nov 2007 22:30:08 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from speedfactory.net (mail6.speedfactory.net [66.23.216.219]) by mx1.freebsd.org (Postfix) with ESMTP id 24C8713C455; Mon, 26 Nov 2007 22:30:02 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from server.baldwin.cx (unverified [66.23.211.162]) by speedfactory.net (SurgeMail 3.8p) with ESMTP id 221393411-1834499 for multiple; Mon, 26 Nov 2007 17:13:47 -0500 Received: from localhost.corp.yahoo.com (john@localhost [127.0.0.1]) (authenticated bits=0) by server.baldwin.cx (8.13.8/8.13.8) with ESMTP id lAQMDGCT010864; Mon, 26 Nov 2007 17:13:22 -0500 (EST) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: Dan Epure Date: Mon, 26 Nov 2007 16:24:51 -0500 User-Agent: KMail/1.9.6 References: <20071118012616.GF19354@iogyte.ro> <20071122085228.M60495@fledge.watson.org> <20071122154741.GA73724@iogyte.ro> In-Reply-To: <20071122154741.GA73724@iogyte.ro> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200711261624.52550.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [127.0.0.1]); Mon, 26 Nov 2007 17:13:22 -0500 (EST) X-Virus-Scanned: ClamAV 0.91.2/4928/Mon Nov 26 13:10:39 2007 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: freebsd-stable@FreeBSD.org, freebsd-current@FreeBSD.org, Robert Watson , csjp@FreeBSD.org Subject: Re: pseudo terminals in 7.0 - pts implementation X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Nov 2007 22:30:08 -0000 On Thursday 22 November 2007 10:47:41 am Dan Epure wrote: > Hi, > > For the moment this feature is only available in HEAD. I think the limit is "only" 512 master/slave pairs. > Should be enough for this year. Is it going to be merged in 6.3 ? > Thanks again. The 512 ptys can easily be merged. We actually are using 1152 ptys at work using a similar patch (just more pty letters). > On Thu, Nov 22, 2007 at 08:53:36AM +0000, Robert Watson wrote: > > > > On Thu, 22 Nov 2007, Dan Epure wrote: > > > >> Thank you for your answer. In this case the first problem (gnu screen) > >> does not deserve any attention because it is related to the ptmx clonig. > >> My goal is to find a way to increase the number os pseudo terminal. the > >> traditional 256 pty is not sufficient for my needs. Is there any way to do > >> this on freebsd other than using ptmx cloning ? > > > > John Baldwin has just merged support for up to 1024 ptys using the > > traditional pty driver, I believe, to HEAD, and plans (or perhaps has > > already) merged it to 7.0. I see no reason not to further merge it to 6.x. > > I've stuck him on the CC list also. > > > > Robert N M Watson > > Computer Laboratory > > University of Cambridge > > > >> > >> > >> On Wed, Nov 21, 2007 at 10:00:02PM +0000, Robert Watson wrote: > >>> > >>> On Sun, 18 Nov 2007, Robert Watson wrote: > >>> > >>>> On Sun, 18 Nov 2007, Dan Epure wrote: > >>>> > >>>>> 7.0-BETA3 still has issues regarding the pts implementation . problems > >>>>> found: 1. - GNU screen: starting a screen, opening a few windows and > >>>>> quiting screen leaves the allocated pseudo terminal in use. 100 screen > >>>>> user, using each one opening 10 windows will deplete the default of > >>>>> 1000 > >>>>> pseudo terminals leaving the system unusable. 2. - 'ls /dev/ptmx' > >>>>> creates > >>>>> an additional entry in /dev/pty/. when the number of entries equals > >>>>> kern.pts.max the system became unusable. > >>>> > >>>> The first of these is likely a reference management bug of some sort -- > >>>> I > >>>> find that if I close a pty in screen by exiting the shell, the pts > >>>> device > >>>> is GC'd properly, but if I close it by killing the session with ctrl-k, > >>>> then the pts device is not properly GC'd and processes hung off it not > >>>> properly killed. I believe that closing the master device is not > >>>> properly > >>>> kicking the slave device and causing its consumers to exit, hence the > >>>> pts > >>>> device not being closd and released. Christian was taking a look at > >>>> this > >>>> a couple of days ago, and I've CC'd him. > >>>> > >>>> The second problem is more tricky, and has to do with the cloning model. > >>>> Similar problems can exist with other variations on the ptmx > >>>> implementation, and I need to give some thought to how to address this. > >>> > >>> Dan, > >>> > >>> So, thinking a bit more about the second problem, I think it is inherrent > >>> to the way we've designed the /dev/ptmx cloning model, which is > >>> unfortunate. My current leaning is to disable the ptmx mechanism in 7.0 > >>> and put together a revised one for 7.1. The reason to do this is to > >>> avoid > >>> encoding the user<->kernel interface for allocating pty's via ptmx along > >>> the current lines, which we'd then need to continue supporting in future > >>> releases. I'm going to spend a bit of time over the next day or two > >>> looking at revising the interface to fix these problems. > >>> > >>> Robert N M Watson > >>> Computer Laboratory > >>> University of Cambridge > >> > > _______________________________________________ > > freebsd-current@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-current > > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" > -- John Baldwin