From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760589AbXGCWZ3 (ORCPT ); Tue, 3 Jul 2007 18:25:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753678AbXGCWZW (ORCPT ); Tue, 3 Jul 2007 18:25:22 -0400 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:39954 "EHLO the-village.bc.nu" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753077AbXGCWZV (ORCPT ); Tue, 3 Jul 2007 18:25:21 -0400 Date: Tue, 3 Jul 2007 23:31:35 +0100 From: Alan Cox To: Morten Helgesen Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: Re: [PATCH] genericserial: Remove bogus optimisation check and dead code paths Message-ID: <20070703233135.502bba84@the-village.bc.nu> In-Reply-To: <468AC156.5040402@sourcepoet.org> References: <20070703152021.6eb8013d@the-village.bc.nu> <468A5F89.70900@sourcepoet.org> <20070703162655.6a001fdc@the-village.bc.nu> <468AC156.5040402@sourcepoet.org> X-Mailer: Claws Mail 2.9.1 (GTK+ 2.10.8; i386-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 03 Jul 2007 23:36:22 +0200 Morten Helgesen wrote: > /* > > Problems to take into account are: > > -1- Interrupts that empty part of the buffer. > -> -2- page faults on the access to userspace. > +> -2- Page faults on access to userspace. #2 no longer applies (don't before the caller) > > -3- Other processes that are also trying to do a "write". #3 no longer applies (locked by tty layer) > - /* get exclusive "write" access to this port (problem 3) */ > + /* Get exclusive "write" access to this port (problem 3) */ > /* This is not a spinlock because we can have a disk access (page > - fault) in copy_from_user */ No copy_from_user any more. Actually that locking code wants review and maybe removal so is another project altogether Definitely an improvement Acked-by: Alan Cox