Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753589AbZIJUGV (ORCPT ); Thu, 10 Sep 2009 16:06:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752320AbZIJUGV (ORCPT ); Thu, 10 Sep 2009 16:06:21 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:41924 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751150AbZIJUGU (ORCPT ); Thu, 10 Sep 2009 16:06:20 -0400 Date: Thu, 10 Sep 2009 17:05:38 -0300 From: Mauro Carvalho Chehab To: "H. Peter Anvin" Cc: Alan Cox , Alan Cox , LKML , Kay Sievers , Andrew Morton , Greg Kroah-Hartman Subject: Re: [PATCH] char/tty_io: fix legacy pty name when more than 256 pty devices are requested Message-ID: <20090910170538.3df10839@caramujo.chehab.org> In-Reply-To: <4AA950C8.1080200@zytor.com> References: <20090908144942.76ddf0e7@caramujo.chehab.org> <4AA6DF50.3030603@zytor.com> <20090908203323.486c129c@caramujo.chehab.org> <4AA6F63F.7090009@zytor.com> <20090908235441.04549a29@caramujo.chehab.org> <4AA73309.8030302@zytor.com> <20090910010512.60a1f523@caramujo.chehab.org> <4AA89B02.1050909@zytor.com> <20090910093301.4ccfd786@caramujo.chehab.org> <20090910150716.66310f02@lxorguk.ukuu.org.uk> <4AA92487.5080401@zytor.com> <20090910161215.5129bd71@caramujo.chehab.org> <4AA950C8.1080200@zytor.com> X-Mailer: Claws Mail 3.3.1 (GTK+ 2.10.4; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1591 Lines: 36 Em Thu, 10 Sep 2009 12:17:28 -0700 "H. Peter Anvin" escreveu: > > In the case of the BSD sockets, the patch is not just an userless fix. This is > > interesting when some applications are ported from other Unix'es and still uses BSD > > pty's, since several other Unix flavors were defining a higher namespace size. > > > > For example, on zOS Unix, a pty device seems to allow up to 10.000 pty numbers (in the > > specific case of zOS Unix, they seem to be defined as /dev/[pt]typ[0-9]...) as shown at: > > www.redbooks.ibm.com/redbooks/pdfs/sg245228.pdf > > > > Yes, but you have to port the application *anyway* do deal with the > namespace. Or create some udev rules for that. > BSD tty allocation is done largely by each application, > which makes it even worse. Furthermore, there is the static allocation > issue, so unless there is a concrete application which needs this *and* > cannot be ported to Unix98 ptys (which is the Right Thing[TM] to do) I > think Alan is right. The amount of static allocation space can be controlled via pty.legacy_count boot parameter. It overrides whatever specified at CONFIG_LEGACY_PTY_COUNT. You can even let LEGACY_PTY_COUNT = 0 and enable the actual numbers of needed legacy ptys via boot parameter, where needed. So, this is not a problem on a real situation. Cheers, Mauro -- 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/