From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261769AbVB1VnD (ORCPT ); Mon, 28 Feb 2005 16:43:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261770AbVB1VnD (ORCPT ); Mon, 28 Feb 2005 16:43:03 -0500 Received: from mustang.oldcity.dca.net ([216.158.38.3]:171 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S261769AbVB1Vm7 (ORCPT ); Mon, 28 Feb 2005 16:42:59 -0500 Subject: Re: Signals/ Communication from kernel to user! From: Lee Revell To: Ravindra Nadgauda Cc: "'Linux Kernel Mailing List'" In-Reply-To: <042701c51dab$561ef650$280e000a@blr.velankani.com> References: <042701c51dab$561ef650$280e000a@blr.velankani.com> Content-Type: text/plain Date: Mon, 28 Feb 2005 16:17:45 -0500 Message-Id: <1109625466.9273.24.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2005-02-28 at 21:06 +0530, Ravindra Nadgauda wrote: > > Hello, > We wanted to establish a communication from kernel module (possibly a > driver) to a user level process. > > Wanted to know whether signals can be used for this purpose OR there any > other (better) methods of communication?? If you need fast IPC forget about signals. They are way too slow. The traditional UNIX way for userspace to talk to the kernel has been ioctls. For various reasons ioctls are not highly regarded in the Linux kernel community. I believe the currently favored method is to have the driver create sysfs entries which userspace read()s and write()s. Really, your question is too vague. It would help if you said what exactly you are trying to accomplish. Lee