Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270743AbUJUU4x (ORCPT ); Thu, 21 Oct 2004 16:56:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270824AbUJUUxN (ORCPT ); Thu, 21 Oct 2004 16:53:13 -0400 Received: from smtp.Lynuxworks.com ([207.21.185.24]:25092 "EHLO smtp.lynuxworks.com") by vger.kernel.org with ESMTP id S270809AbUJUUuE (ORCPT ); Thu, 21 Oct 2004 16:50:04 -0400 Date: Thu, 21 Oct 2004 13:49:39 -0700 To: Bill Huey Cc: Jens Axboe , Thomas Gleixner , Rui Nuno Capela , Ingo Molnar , LKML , Lee Revell , mark_h_johnson@raytheon.com, "K.R. Foley" , Adam Heath , Florian Schmidt , Michal Schmidt , Fernando Pablo Lopez-Lezcano Subject: Re: [patch] Real-Time Preemption, -RT-2.6.9-rc4-mm1-U8 Message-ID: <20041021204939.GA25190@nietzsche.lynx.com> References: <30690.195.245.190.93.1098349976.squirrel@195.245.190.93> <1098350190.26758.24.camel@thomas> <20041021095344.GA10531@suse.de> <1098352441.26758.30.camel@thomas> <20041021101103.GC10531@suse.de> <20041021195842.GA23864@nietzsche.lynx.com> <20041021201443.GF32465@suse.de> <20041021202422.GA24555@nietzsche.lynx.com> <20041021203350.GK32465@suse.de> <20041021203821.GA24628@nietzsche.lynx.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041021203821.GA24628@nietzsche.lynx.com> User-Agent: Mutt/1.5.6+20040907i From: Bill Huey (hui) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1308 Lines: 26 On Thu, Oct 21, 2004 at 01:38:21PM -0700, Bill Huey wrote: > On Thu, Oct 21, 2004 at 10:33:50PM +0200, Jens Axboe wrote: > > Linux semaphores (being counted) have always been a fine fit for things > > like the loop use, where you get to down it 10 times because you have 10 > > items pending. I know this isn't the traditional mutex and that it > > doesn't protect data as such, but is was never abuse. It isn't overload. > > Doing it with a traditional mutex (I'm assuming this is what mutex_t is > > in Ingos tree) would be overload and a bad idea, indeed. > > Well, this is something that's got to be considered by the larger Linux > community and whether these conventions are to be kept or removed. It's > a larger issue than what can be address in Ingo's preemption patch, but > with inevitable need for something like this in the kernel (hard RT) > it's really unavoidable collision. IMO, it's got to go, which is a nasty > change. But this is a non-fatal case. I'll see if I can change this logic to not completely die when this case is detected. bill - 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/