Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754090AbYHKOMW (ORCPT ); Mon, 11 Aug 2008 10:12:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751763AbYHKOMN (ORCPT ); Mon, 11 Aug 2008 10:12:13 -0400 Received: from mx1.redhat.com ([66.187.233.31]:37761 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751700AbYHKOMM (ORCPT ); Mon, 11 Aug 2008 10:12:12 -0400 Message-ID: <48A0487B.7080600@redhat.com> Date: Mon, 11 Aug 2008 07:11:07 -0700 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Thunderbird 2.0.0.16 (X11/20080723) MIME-Version: 1.0 To: Dario Faggioli CC: linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Steven Rostedt , Andrew Morton Subject: Re: [RFC 0/1][PATCH] POSIX SCHED_SPORADIC implementation for tasks and groups References: <1218462574.6450.24.camel@Palanthas> In-Reply-To: <1218462574.6450.24.camel@Palanthas> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1554 Lines: 37 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Dario Faggioli wrote: > I'm spending some time implementing the POSIX real-time SCHED_SPORADIC > scheduling policy on top of the mainline Linux kernel, and here it is > the code in its very first version. I'm not commenting on the code or usefulness of ht features. I just want to point out a problem. The authors of that POSIX extension unfortunately decided to extend the sched_param structure. If you look at the definition of that structure Linux uses you'll see that there is no place for this. I.e., any implementation of that feature following the POSIX spec to the letter will introduce major headache in the form of binary incompatibility. In case the features is useful enough (I actually always thought it isn't an have actually proposed to remove it again from POSIX) then I would rather prefer to not claim support for this feature in the POSIX way. One could still implement it as described. But change the interface to not require the sched_param change. - -- ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkigSHsACgkQ2ijCOnn/RHS23QCfWNJRqnrhgSXGpnNag/nVeKcC uwIAn3fUIwku+i+xegBDhfh5yaIW/VCo =LCa/ -----END PGP SIGNATURE----- -- 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/