From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755386AbYIJXjT (ORCPT ); Wed, 10 Sep 2008 19:39:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752168AbYIJXjJ (ORCPT ); Wed, 10 Sep 2008 19:39:09 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:52845 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752150AbYIJXjH (ORCPT ); Wed, 10 Sep 2008 19:39:07 -0400 Date: Wed, 10 Sep 2008 16:39:02 -0700 From: Andrew Morton To: Joe Peterson Cc: alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org Subject: Re: [PATCH] TTY: Fix loss of echoed characters (2nd follow-on PATCH attached) Message-Id: <20080910163902.2b7ac22b.akpm@linux-foundation.org> In-Reply-To: <48C6DFA4.5040406@skyrush.com> References: <200807252257.m6PMvieO003213@imap1.linux-foundation.org> <48AC3A16.4080209@skyrush.com> <48B3F9F7.2050503@skyrush.com> <48C54EC2.4060901@skyrush.com> <20080908173250.2452c5b8.akpm@linux-foundation.org> <20080909115536.1664d57a@lxorguk.ukuu.org.uk> <20080909104325.4653190b.akpm@linux-foundation.org> <48C6DFA4.5040406@skyrush.com> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-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 On Tue, 09 Sep 2008 14:42:12 -0600 Joe Peterson wrote: > 1) Fix tab erasure handling > 2) Improve locking when working with the echo buffer > 3) Remove the big kernel lock (BKL) from n_tty > > Tab erasure handling is now more robust and able to handle non-zero > canon column cases more correctly. This is done by making correct use > of what is known in the eraser function (read buffer contents) and what > is known at the time of processing the tab erasure (column state). > > Also, better locking of the echo buffer will now prevent any attempts to > process partial multi-byte echo operations. And since the echo buffer > code now isolates the tty column state code to the process_out* and > process_echoes functions, we can remove the big kernel lock (BKL) > and replace it with more modern mutex locks. Boy. Has this been carefully tested with lockdep enabled?