From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1164234AbWLHAlj (ORCPT ); Thu, 7 Dec 2006 19:41:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1164239AbWLHAlj (ORCPT ); Thu, 7 Dec 2006 19:41:39 -0500 Received: from ftp.linux-mips.org ([194.74.144.162]:52521 "EHLO ftp.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1164234AbWLHAli (ORCPT ); Thu, 7 Dec 2006 19:41:38 -0500 Date: Fri, 8 Dec 2006 00:41:30 +0000 From: Ralf Baechle To: linux-kernel@vger.kernel.org Subject: [PATCH] Remove useless memory barrier. Message-ID: <20061208004129.GA17754@linux-mips.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I don't see why there is a memory barrier in copy_from_read_buf() at all. Even if it was useful spin_unlock_irqrestore implies a barrier. Signed-off-by: Ralf Baechle diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index 603b9ad..8df7ff3 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -1151,7 +1151,6 @@ static int copy_from_read_buf(struct tty n = min(*nr, n); spin_unlock_irqrestore(&tty->read_lock, flags); if (n) { - mb(); retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n); n -= retval; spin_lock_irqsave(&tty->read_lock, flags);