Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 13 Jun 2002 05:43:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 13 Jun 2002 05:43:28 -0400 Received: from pizda.ninka.net ([216.101.162.242]:38107 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Thu, 13 Jun 2002 05:43:23 -0400 Date: Thu, 13 Jun 2002 02:38:56 -0700 (PDT) Message-Id: <20020613.023856.87216149.davem@redhat.com> To: david-b@pacbell.net Cc: roland@topspin.com, benh@kernel.crashing.org, linux-kernel@vger.kernel.org Subject: Re: PCI DMA to small buffers on cache-incoherent arch From: "David S. Miller" In-Reply-To: <3D0829ED.1020809@pacbell.net> X-Mailer: Mew version 2.1 on Emacs 21.1 / Mule 5.0 (SAKAKI) 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 From: David Brownell Date: Wed, 12 Jun 2002 22:13:17 -0700 David S. Miller wrote: > We have two problems we want to solve, the DMA alignment stuff and > using consistent memory for these small buffers. Therefore moving to > consistent memory (by whatever mechanism the USB desires to implement > this) is the way to go. Right, the alignment stuff is a correctness issue, the consistent memory issue is a performance concern. I like to think that 2.5 will have a lot less correctness issues in the USB stack, so it can start to pay more attention to performance concerns. I want to reemphasize that by going to consistent memory we solve both problems, in particular the alignment stuff becomes a non-issue. - 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/