From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 95C4FB7B70 for ; Thu, 27 Aug 2009 19:23:45 +1000 (EST) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by ozlabs.org (Postfix) with ESMTP id 0E32EDDD04 for ; Thu, 27 Aug 2009 19:23:44 +1000 (EST) Date: Thu, 27 Aug 2009 10:08:09 +0100 From: Alan Cox To: Benjamin Herrenschmidt Subject: Re: Extending virtio_console to support multiple ports Message-ID: <20090827100809.5f0aa0a7@linux.intel.com> In-Reply-To: <1251346023.20467.21.camel@pasglop> References: <1251181044-3696-1-git-send-email-amit.shah@redhat.com> <20090826112718.GA11117@amit-x200.redhat.com> <20090826154552.GA31910@amit-x200.redhat.com> <1251346023.20467.21.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: kvm@vger.kernel.org, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, miltonm@bga.com, qemu-devel@nongnu.org, borntraeger@de.ibm.com, brueckner@linux.vnet.ibm.com, Amit Shah , virtualization@lists.linux-foundation.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > - Then, are we certain that there's no case where the tty layer will > call us with some lock held or in an atomic context ? To be honest, > I've totally lost track of the locking rules in tty land lately so it > might well be ok, but something to verify. Some of the less well behaved line disciplines do this and always have done. Alan From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752036AbZH0JNw (ORCPT ); Thu, 27 Aug 2009 05:13:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751937AbZH0JNv (ORCPT ); Thu, 27 Aug 2009 05:13:51 -0400 Received: from mga09.intel.com ([134.134.136.24]:48267 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751898AbZH0JNu (ORCPT ); Thu, 27 Aug 2009 05:13:50 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.44,285,1249282800"; d="scan'208";a="545216571" Date: Thu, 27 Aug 2009 10:08:09 +0100 From: Alan Cox To: Benjamin Herrenschmidt Cc: Amit Shah , qemu-devel@nongnu.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, borntraeger@de.ibm.com, linux-kernel@vger.kernel.org, miltonm@bga.com, linuxppc-dev@ozlabs.org, brueckner@linux.vnet.ibm.com Subject: Re: Extending virtio_console to support multiple ports Message-ID: <20090827100809.5f0aa0a7@linux.intel.com> In-Reply-To: <1251346023.20467.21.camel@pasglop> References: <1251181044-3696-1-git-send-email-amit.shah@redhat.com> <20090826112718.GA11117@amit-x200.redhat.com> <20090826154552.GA31910@amit-x200.redhat.com> <1251346023.20467.21.camel@pasglop> Organization: Intel X-Mailer: Claws Mail 3.7.2 (GTK+ 2.16.5; x86_64-redhat-linux-gnu) 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 > - Then, are we certain that there's no case where the tty layer will > call us with some lock held or in an atomic context ? To be honest, > I've totally lost track of the locking rules in tty land lately so it > might well be ok, but something to verify. Some of the less well behaved line disciplines do this and always have done. Alan From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Mgb3P-00062Z-TP for qemu-devel@nongnu.org; Thu, 27 Aug 2009 05:13:59 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Mgb3L-0005mk-2Y for qemu-devel@nongnu.org; Thu, 27 Aug 2009 05:13:59 -0400 Received: from [199.232.76.173] (port=59333 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Mgb3K-0005mV-Vl for qemu-devel@nongnu.org; Thu, 27 Aug 2009 05:13:55 -0400 Received: from mga09.intel.com ([134.134.136.24]:43953) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Mgb3K-0000Ey-Mq for qemu-devel@nongnu.org; Thu, 27 Aug 2009 05:13:54 -0400 Date: Thu, 27 Aug 2009 10:08:09 +0100 From: Alan Cox Message-ID: <20090827100809.5f0aa0a7@linux.intel.com> In-Reply-To: <1251346023.20467.21.camel@pasglop> References: <1251181044-3696-1-git-send-email-amit.shah@redhat.com> <20090826112718.GA11117@amit-x200.redhat.com> <20090826154552.GA31910@amit-x200.redhat.com> <1251346023.20467.21.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: Extending virtio_console to support multiple ports List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Benjamin Herrenschmidt Cc: kvm@vger.kernel.org, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, miltonm@bga.com, qemu-devel@nongnu.org, borntraeger@de.ibm.com, brueckner@linux.vnet.ibm.com, Amit Shah , virtualization@lists.linux-foundation.org > - Then, are we certain that there's no case where the tty layer will > call us with some lock held or in an atomic context ? To be honest, > I've totally lost track of the locking rules in tty land lately so it > might well be ok, but something to verify. Some of the less well behaved line disciplines do this and always have done. Alan