Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268074AbUJOCBc (ORCPT ); Thu, 14 Oct 2004 22:01:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268101AbUJOCBb (ORCPT ); Thu, 14 Oct 2004 22:01:31 -0400 Received: from igw2.watson.ibm.com ([129.34.20.6]:33458 "EHLO igw2.watson.ibm.com") by vger.kernel.org with ESMTP id S268074AbUJOCB3 (ORCPT ); Thu, 14 Oct 2004 22:01:29 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Thu, 14 Oct 2004 22:00:51 -0400 (EDT) To: Roland Dreier Cc: karim@opersys.com, Ingo Molnar , linux-kernel@vger.kernel.org, Thomas Zanussi , Robert Wisniewski , Richard J Moore , Michel Dagenais Subject: Re: [patch] Real-Time Preemption, -VP-2.6.9-rc4-mm1-U0 In-Reply-To: <52u0swddpk.fsf@topspin.com> References: <20041011215909.GA20686@elte.hu> <20041012091501.GA18562@elte.hu> <20041012123318.GA2102@elte.hu> <20041012195424.GA3961@elte.hu> <20041013061518.GA1083@elte.hu> <20041014002433.GA19399@elte.hu> <416F0071.3040304@opersys.com> <20041014234603.GA22964@elte.hu> <416F14B4.8070002@opersys.com> <52u0swddpk.fsf@topspin.com> X-Mailer: VM 6.43 under 20.4 "Emerald" XEmacs Lucid Message-ID: <16751.12005.419748.661651@kix.watson.ibm.com> From: Robert Wisniewski Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1006 Lines: 28 Theoretically a problem, in practice not, i.e., good enough for soft/normal real-time, not hard real-time; probably wouldn't want my heart monitor on it, but then I wouldn't be using Linux for that either :-) Robert Wisniewski The K42 MP OS Project Advanced Operating Systems Scalable Parallel Systems IBM T.J. Watson Research Center 914-945-3181 http://www.research.ibm.com/K42/ bob@watson.ibm.com Roland Dreier writes: > Karim> cmpxchg (basically: try reserve; if fail retry; else > Karim> write), with per-cpu buffers. > > Not sure if I really understand the context where Ingo would use this, > but this lockless scheme doesn't seem to be safe for realtime; the > retry can potentially happen an arbitrary number of times. > > - Roland - 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/