From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932618AbYDPQvY (ORCPT ); Wed, 16 Apr 2008 12:51:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758319AbYDPQvQ (ORCPT ); Wed, 16 Apr 2008 12:51:16 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:35457 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757899AbYDPQvQ convert rfc822-to-8bit (ORCPT ); Wed, 16 Apr 2008 12:51:16 -0400 Date: Wed, 16 Apr 2008 09:50:26 -0700 From: Arjan van de Ven To: Oliver Neukum Cc: Matthew Wilcox , Ingo Oeser , Linus Torvalds , Andi Kleen , Peter Zijlstra , Bart Van Assche , Roland Dreier , Ingo Molnar , Daniel Walker , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Replace completions with semaphores Message-ID: <20080416095026.658bdd21@laptopd505.fenrus.org> In-Reply-To: <200804161831.10510.oliver@neukum.org> References: <4803AD91.5020001@firstfloor.org> <200804161807.25582.ioe-lkml@rameria.de> <20080416161652.GK9191@parisc-linux.org> <200804161831.10510.oliver@neukum.org> Organization: Intel X-Mailer: Claws Mail 3.2.0 (GTK+ 2.12.5; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Apr 2008 18:31:08 +0200 Oliver Neukum wrote: > Am Mittwoch, 16. April 2008 18:16:52 schrieb Matthew Wilcox: > > The basic idea is that you get back a cookie from the > > kcounter_claim() which you have to hand to the kcounter_release() > > function so it knows which one you released.  It's similar to mutex > > debugging except > > So in addition to the kcounter we need to save a token in a data > structure? In fact, there must be a data structure that can house > that token. So you can no longer live with a pointer just to a device > descriptor, but every individual use of a resource must have an > associated data structure? yup. For kcounters there is a clear owner for each "slot". [This is the part that makes it debugable again) Now for non-debug builds, the space taken for the token can be.. zero depending on how we define the types for it. > > Regards > Oliver > > -- > 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/ -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org