Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753877AbYFUXBR (ORCPT ); Sat, 21 Jun 2008 19:01:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751470AbYFUXBF (ORCPT ); Sat, 21 Jun 2008 19:01:05 -0400 Received: from one.firstfloor.org ([213.235.205.2]:36093 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751153AbYFUXBE (ORCPT ); Sat, 21 Jun 2008 19:01:04 -0400 Message-ID: <485D8829.2060901@firstfloor.org> Date: Sun, 22 Jun 2008 01:00:57 +0200 From: Andi Kleen User-Agent: Thunderbird 1.5.0.12 (X11/20060911) MIME-Version: 1.0 To: Alan Stern CC: Kernel development list , AntonioLin , David Vrabel Subject: Re: Scatter-gather list constraints References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 669 Lines: 20 >> - Is it performance critical? > > For people using wireless USB drives, yes. But only if there is a lot of 512 byte block IO? The only case I can think of right now would be XFS log IO and perhaps some O_DIRECT/raw device accesses. Or how did you determine it is critical? Was there some important workload where most of the requests had this form? If it's only an relative oddball just copying is fine imho. -Andi -- 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/