Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264500AbUFNV5a (ORCPT ); Mon, 14 Jun 2004 17:57:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264513AbUFNV5a (ORCPT ); Mon, 14 Jun 2004 17:57:30 -0400 Received: from zcars04f.nortelnetworks.com ([47.129.242.57]:19103 "EHLO zcars04f.nortelnetworks.com") by vger.kernel.org with ESMTP id S264500AbUFNV53 (ORCPT ); Mon, 14 Jun 2004 17:57:29 -0400 Message-ID: <40CE1F42.1020407@nortelnetworks.com> Date: Mon, 14 Jun 2004 17:57:22 -0400 X-Sybari-Space: 00000000 00000000 00000000 00000000 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040113 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Oliver Neukum CC: Steve French , linux-kernel@vger.kernel.org Subject: Re: upcalls from kernel code to user space daemons References: <200406142341.13340.oliver@neukum.org> In-Reply-To: <200406142341.13340.oliver@neukum.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 738 Lines: 19 Oliver Neukum wrote: > > userspace daemon loops on ioctl() > > kernel portion of ioctl call goes to sleep until something to do > > when needed, fill in data and return to userspace > > userspace does stuff, then passes data back down via ioctl() > > ioctl() puts userspace back to sleep and continues on with other work > > You could just as well implement an ordinary read() Not quite. The userspace is passing data down as well. I don't know how you'd do that with read(). Chris - 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/