Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262847AbUJ1JSg (ORCPT ); Thu, 28 Oct 2004 05:18:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262846AbUJ1JSg (ORCPT ); Thu, 28 Oct 2004 05:18:36 -0400 Received: from smtp3.netcabo.pt ([212.113.174.30]:22790 "EHLO exch01smtp11.hdi.tvcabo") by vger.kernel.org with ESMTP id S262847AbUJ1JSa (ORCPT ); Thu, 28 Oct 2004 05:18:30 -0400 Message-ID: <26253.195.245.190.93.1098955051.squirrel@195.245.190.93> In-Reply-To: <20041028085656.GA21535@elte.hu> References: <20041025104023.GA1960@elte.hu> <20041027001542.GA29295@elte.hu> <5225.195.245.190.94.1098880980.squirrel@195.245.190.94> <20041027135309.GA8090@elte.hu> <12917.195.245.190.94.1098890763.squirrel@195.245.190.94> <20041027205126.GA25091@elte.hu> <20041027211957.GA28571@elte.hu> <33083.192.168.1.5.1098919913.squirrel@192.168.1.5> <20041028063630.GD9781@elte.hu> <20668.195.245.190.93.1098952275.squirrel@195.245.190.93> <20041028085656.GA21535@elte.hu> Date: Thu, 28 Oct 2004 10:17:31 +0100 (WEST) Subject: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4 From: "Rui Nuno Capela" To: "Ingo Molnar" Cc: linux-kernel@vger.kernel.org, "Lee Revell" , mark_h_johnson@raytheon.com, "K.R. Foley" , "Bill Huey" , "Adam Heath" , "Florian Schmidt" , "Thomas Gleixner" , "Michal Schmidt" , "Fernando Pablo Lopez-Lezcano" , "Karsten Wiese" User-Agent: SquirrelMail/1.4.3a X-Mailer: SquirrelMail/1.4.3a MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Priority: 3 (Normal) Importance: Normal X-OriginalArrivalTime: 28 Oct 2004 09:18:29.0020 (UTC) FILETIME=[16376DC0:01C4BCCF] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2343 Lines: 59 Ingo Molnar wrote: > > * Rui Nuno Capela wrote: > >> The following table compares the state between my RT-U3 and RT-V0.4.3 >> configurations, regarding only the mentioned options: >> >> option RT-U3.0 RT-V0.4.3 >> ---------------------------- ---------- --------- >> CONFIG_DEBUG_SLAB n n >> CONFIG_DEBUG_PREEMPT y y >> CONFIG_DEBUG_SPINLOCK_SLEEP n - >> CONFIG_PREEMPT_TIMING n n >> CONFIG_RWSEM_DEADLOCK_DETECT - y >> CONFIG_FRAME_POINTER y y >> CONFIG_DEBUG_STACKOVERFLOW y y >> CONFIG_DEBUG_STACK_USAGE n n >> CONFIG_DEBUG_PAGEALLOC n n >> >> (dash "-" means that the option is not available in the config). >> >> As you can see, it can only be CONFIG_RWSEM_DEADLOCK_DETECT, being new >> in RT-V0.4.3, that is probably affecting on RT-V0.4.3. I'll try to >> rebuild and test all over without it, and see if it gets any better. > > note that DEBUG_PREEMPT got more expensive in the -V kernels. I'd > suggest to disable all the 'y' ones in both the -U and -V kernel and > compare them then. > > but especially the userspace overhead seems to be significantly higher > in the -V kernel so i'm not quite sure it can all be attributed to > debugging overhead. We'll see. > > also, how does the context-switching rate compare between the two tests? > This test is pretty steady when it's running, so the context-switch > rates can be directly compared, correct? > OK. That was it. After switching off CONFIG_RWSEM_DEADLOCK_DETECT on RT-V0.4.3, I can say that it's now on par to RT-U3. Later today, I will conduct some extendeded testing, where I'll able to compare the jackd performance between vanilla, RT-U3 and RT-V0.4.3, on my UP laptop. All kernel configurations will be stripped off from all the debug options. I will take note of xrun rate, jackd scheduling delay histogram, and cpu usage. Context switch rate will be also acquainted. Anything else? -- rncbc aka Rui Nuno Capela rncbc@rncbc.org - 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/