From owner-freebsd-hackers Thu Dec 13 19:54:46 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from mass.dis.org (mass.dis.org [216.240.45.41]) by hub.freebsd.org (Postfix) with ESMTP id BB15D37B405 for ; Thu, 13 Dec 2001 19:54:42 -0800 (PST) Received: from mass.dis.org (localhost [127.0.0.1]) by mass.dis.org (8.11.6/8.11.3) with ESMTP id fBE40al06791; Thu, 13 Dec 2001 20:00:37 -0800 (PST) (envelope-from msmith@mass.dis.org) Message-Id: <200112140400.fBE40al06791@mass.dis.org> To: "Mark Brown" Cc: hackers@freebsd.org Subject: Re: uiomove (CPU) performance? In-Reply-To: Message from "Mark Brown" of "Thu, 13 Dec 2001 22:06:42 EST." Date: Thu, 13 Dec 2001 20:00:36 -0800 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > The code is kernel mode so I do not think the memcopy routine uses uiomove > in this case(I could be wrong). Also this code is multiplatform so > that the general code uses memcopy and developers optimize the code to work > on the different platforms they are in. Speed is not my > concern right now because we can max out the speed of the device we are > copying from. Our problem lies in the CPU utilization. Will > uiomove be better than memcopy in that respect or the same? Since the restriction is memory bandwidth for the copy, performance is unlikely to be much different. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message