From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757802AbWK0LKi (ORCPT ); Mon, 27 Nov 2006 06:10:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758039AbWK0LKi (ORCPT ); Mon, 27 Nov 2006 06:10:38 -0500 Received: from ns.suse.de ([195.135.220.2]:17332 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1757802AbWK0LKh (ORCPT ); Mon, 27 Nov 2006 06:10:37 -0500 To: "Cestonaro, Thilo (external)" Cc: linux-kernel@vger.kernel.org Subject: Re: Weird wasting of time between ioctl() and ioctl dispatcher References: From: Andi Kleen Date: 27 Nov 2006 12:10:33 +0100 In-Reply-To: Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Cestonaro, Thilo \(external\)" writes: > I'm a developer for Fujitsu Siemens Computers, working on a program which has it's own kernel modules and userland components. > Now cause the program should be released we have done some testing and during this testphase a wierd wasting of time occured > during the call of the ioctl() in the userland component and the actuall entering of the dispatcher function in the module. > It takes 3 min. until the call at last enters my dispatcher. Something else is holding the big kernel lock for that long. Most likely it's your own code. Consider using a ->unlocked_ioctl -Andi