Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268971AbUJKP2A (ORCPT ); Mon, 11 Oct 2004 11:28:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269085AbUJKP15 (ORCPT ); Mon, 11 Oct 2004 11:27:57 -0400 Received: from ns1.kazix.com ([69.93.95.154]:30644 "EHLO server1.kazix.com") by vger.kernel.org with ESMTP id S268971AbUJKP0h (ORCPT ); Mon, 11 Oct 2004 11:26:37 -0400 From: Vadim Lebedev Organization: MBDSYS To: linux-kernel@vger.kernel.org Subject: Re: [ANNOUNCE] Linux 2.6 Real Time Kernel Date: Mon, 11 Oct 2004 17:28:39 +0200 User-Agent: KMail/1.6.1 MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <200410111728.39200.vadim@mbdsys.com> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - server1.kazix.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - mbdsys.com X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1139 Lines: 27 Sven-Thorsten Dietrich wrote in message news:<2Nir3-4iC-13@gated-at.bofh.it>... > Announcing the availability of prototype real-time (RT) > enhancements to the Linux 2.6 kernel. Reading the sources i believe that __p_mutex_up is not constant time operation because of __p_mutex_down.... It is clear that __p_mutex_down is not constant time operation because of insertion into the priority-sorted sleepers list. However both __p_mutex_down and __p_mutex_up are synchronize on the same global spinlock (m_spin_lock) .... so if the __p_mutex_down is holding this spinlock while inserting NO other process(or) is able to perform any __p_mutex operation... Maybe the better idea would be to have a per-mutex spinlock? or even better, given that the task->rt_priority have a finite range maybe each mutex can have a table of sleeper lists indexed by rt_priority? Vadim - 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/