Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262667AbVDPOXw (ORCPT ); Sat, 16 Apr 2005 10:23:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262668AbVDPOXw (ORCPT ); Sat, 16 Apr 2005 10:23:52 -0400 Received: from ms-smtp-01.nyroc.rr.com ([24.24.2.55]:10746 "EHLO ms-smtp-01.nyroc.rr.com") by vger.kernel.org with ESMTP id S262667AbVDPOXu (ORCPT ); Sat, 16 Apr 2005 10:23:50 -0400 Subject: Re: FUSYN and RT From: Steven Rostedt To: john cooper Cc: Sven Dietrich , "'Inaky Perez-Gonzalez'" , robustmutexes@lists.osdl.org, mingo@elte.hu, linux-kernel@vger.kernel.org, "'Esben Nielsen'" In-Reply-To: <42610DAC.5070506@timesys.com> References: <000801c54230$73a0f940$c800a8c0@mvista.com> <42610DAC.5070506@timesys.com> Content-Type: text/plain Organization: Kihon Technologies Date: Sat, 16 Apr 2005 10:23:05 -0400 Message-Id: <1113661385.4294.136.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.1.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1169 Lines: 28 On Sat, 2005-04-16 at 09:05 -0400, john cooper wrote: > Sven Dietrich wrote: [...] > > This one probably should be a raw_spinlock. > > This lock is only held to protect access to the queues. > > Since the queues are already priority ordered, there is > > little benefit to ordering -the order of insertion- > > in case of contention on a queue, compared with the complexity. > > The choice of lock type should derive from both the calling > context and the length of time the lock is expected to be held. > In this case, I don't think time matters for choice of lock. Time matters to keep it short since it does need the raw_spin_lock. This lock is part of the whole locking scheme, and would be similar to not using raw_spin_locks in the implementation of rt_mutex. Well, not exactly the same, but if we want the fusyn code to use the same code as rt_mutex for PI, then it will need to be a raw_spin_lock. -- Steve - 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/