Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760294AbZJMPeP (ORCPT ); Tue, 13 Oct 2009 11:34:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760285AbZJMPeO (ORCPT ); Tue, 13 Oct 2009 11:34:14 -0400 Received: from adsl-70-250-156-241.dsl.austtx.swbell.net ([70.250.156.241]:38520 "EHLO gw.microgate.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756448AbZJMPeN (ORCPT ); Tue, 13 Oct 2009 11:34:13 -0400 Subject: Re: [Bug #14388] keyboard under X with 2.6.31 From: Paul Fulghum To: Linus Torvalds Cc: Alan Cox , Nix , "Justin P. Mattock" , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Boyan , Dmitry Torokhov , Ed Tomlinson , =?ISO-8859-1?Q?Fr=E9d=E9ric?= "L. W. Meunier" , OGAWA Hirofumi In-Reply-To: References: <56acieJJ2fF.A.nEB.Hzl0KB@chimera> <87ljjgfcbu.fsf@spindle.srvr.nix> <20091013113232.384b2432@lxorguk.ukuu.org.uk> Content-Type: text/plain Date: Tue, 13 Oct 2009 10:33:00 -0500 Message-Id: <1255447980.3898.3.camel@x2.microgate.com> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 (2.8.3-2.fc6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 924 Lines: 23 On Tue, 2009-10-13 at 07:39 -0700, Linus Torvalds wrote: > It's not a f*cking performance tweak, and you're ludicrous to claim it is. > It's pointless, and it's making the code _slower_ rather than faster. > > Lookie here, Alan - the common sequence is crap like this: > > tty_buffer_request_room(tty, buf->size); > tty_insert_flip_string(tty, buf->base, buf->size); The performance tweak of tty_prepare_xxx is that you fill the tty_buffer directly instead of writing data first to a staging buffer and then calling tty_insert_flip_string, which just copies from the staging buffer to the tty_buffer. So it saves a copy operation. -- Paul Fulghum Microgate Systems, Ltd -- 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/