Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752085AbXIDIGW (ORCPT ); Tue, 4 Sep 2007 04:06:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752936AbXIDIGD (ORCPT ); Tue, 4 Sep 2007 04:06:03 -0400 Received: from mail.gmx.net ([213.165.64.20]:35449 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752698AbXIDIF6 (ORCPT ); Tue, 4 Sep 2007 04:05:58 -0400 X-Authenticated: #24879014 X-Provags-ID: V01U2FsdGVkX19G2yg7yPpGV5hpy1mna+K562CxFkmQH9n6iLe9WQ oAmmeZhKXeClx4 Message-ID: <46DD116C.4040301@gmx.net> Date: Tue, 04 Sep 2007 10:03:56 +0200 From: Michael Kerrisk User-Agent: Thunderbird 1.5.0.8 (X11/20060911) MIME-Version: 1.0 To: Davide Libenzi CC: Randy Dunlap , Andrew Morton , Thomas Gleixner , lkml , Linux Torvalds , Ulrich Drepper , stable@kernel.org, Christoph Hellwig , Jan Engelhardt , Jonathan Corbet Subject: Re: [PATCH] Revised timerfd() interface References: <20070825064114.107820@gmx.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1902 Lines: 57 Davide, >> Davide -- ping! Can you please offer your comments about this change, and >> also thoughts on Jon's and my comments about a more radical API change >> later in this thread. > > IMO the complexity of the resulting API (and resulting patch), and the ABI > change, is not justified by the added value. Neither of the proposed APIs (either my multiplexed version of timerfd() or Jon's/my idea of using three system calls (like POSIX timers), or the notion of timerfd() integrated with POSIX timers) is more complicated than the existing POSIX timers API. The ABI change doesn't really matter, since timerfd() was broken in 2.6.22 anyway. Both previous APIs provided the features I have described provide: * the ability to fetch the old timer value when applying a new setting * the ability to non-destructively fetch the amount of time remaining on a timer. This is clearly useful for timers -- but you have not explained why you think this is not necessary for timerfd timers. Please -- let's do timerfd() better. Either three syscalls like: timerfd_create() timerfd_settime() timer_gettime() (the analogs of timer_create(), timer_settime(), timer_gettime()). Or (if possible, and even better) timerfd() integrated with POSIX timers. Then we have a good API for the coming decades. I'm prepared to help out with patches (for what my help is worth ;-)). Cheers, Michael -- Michael Kerrisk maintainer of Linux man pages Sections 2, 3, 4, 5, and 7 Want to help with man page maintenance? Grab the latest tarball at http://www.kernel.org/pub/linux/docs/manpages/ read the HOWTOHELP file and grep the source files for 'FIXME'. - 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/