From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Subject: Re: UIO - interrupt performance Date: Mon, 20 Oct 2008 14:48:58 +0200 Message-ID: <20081020144858.1f074d7b@surf> References: <5958B8D7916AB84781FE0E7B57C218CB75AB98@306900ANEX2.global.avaya.com> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <5958B8D7916AB84781FE0E7B57C218CB75AB98@306900ANEX2.global.avaya.com> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: linux-embedded@vger.kernel.org Le Mon, 20 Oct 2008 10:55:17 +0100, "Douglas, Jim (Jim)" a =C3=A9crit : > Do you know what the *technical* disadvantages of this approach might > be? I am most concerned about possible impact on interrupt handling.=20 >=20 > For example, I assume the context switching overhead is higher, and > that interrupt latency is more difficult to predict? =20 There was a presentation on UIO in embedded systems at the latest Embedded Linux Conference in April. The presentation includes a small analysis of UIO's overhead with regard to interrupt latency. See http://www.celinux.org/elc08_presentations/uio080417celfelc08.pdf Sincerly, Thomas --=20 Thomas Petazzoni, Free Electrons Kernel, drivers and embedded Linux development, consulting, training and support. http://free-electrons.com