Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932627AbWBYRc6 (ORCPT ); Sat, 25 Feb 2006 12:32:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932636AbWBYRc6 (ORCPT ); Sat, 25 Feb 2006 12:32:58 -0500 Received: from ms-smtp-04.nyroc.rr.com ([24.24.2.58]:46307 "EHLO ms-smtp-04.nyroc.rr.com") by vger.kernel.org with ESMTP id S932627AbWBYRc5 (ORCPT ); Sat, 25 Feb 2006 12:32:57 -0500 Date: Sat, 25 Feb 2006 12:32:42 -0500 (EST) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Esben Nielsen cc: Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: 2.6.15-rt17 In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2485 Lines: 73 On Sat, 25 Feb 2006, Esben Nielsen wrote: > On Thu, 23 Feb 2006, Thomas Gleixner wrote: > > > On Wed, 2006-02-22 at 17:50 +0100, Esben Nielsen wrote: > > > I didn't know anyone looked at my patch! I am ofcourse happy about it :-) > > > > Was just delayed due to other work in progress. > > > > You didn't use the "TestRTMutex" I send along with the patch :-( > > Since I learned to use unittesting that way I have been a big fan. It does > catch a lot of stupid bugs without having to wait for the program to get > there while keeping the ability to debug with gdb and fix it right away. > And most important: you can keep the tests and check if your program still > parses them after a rewrite. Very usefull to prevent repeating bugs. > > So here is the issues I have found: > > 1) grablockBKL.tst failes. Apparently you can "grab" the BKL now? Is this > intended? I have updated the test to accept this. since the BKL is now released on semaphores, I guess this is ok. > > 2) 2locksdeadlock.tst loops forever. It is a livelock: When two RT-tasks > "deadlocks" on two mutexes they keep waking up each other in other. I > quickly fixed that bug. I actually thought about that. But it still is an improvement, since it doesn't deadlock the kernel. Just all processes that are of lower priority. This still should be fixed, but it needs to not cause any noticable overhead. > > 3) While fixing that I came to think about what happens when you signal a > task blocked on a task blocked on a task. I thus wrote > 2lock3tasksBoostSignal.tst. Well, the priorities wasn't set back > correctly. I fixed that too. > > I have attached the patch againt 2.6.17-rt17 (and therefore also > included the previous patch) along with the updated tester and tests. > > Esben I'll take a look at this tomorrow. -- Steve > > > > > That was why I had _reversed_ the lock ordering relative to normal in the > > > original patch: First lock task->pi_lock. Assign lock. Lock > > > lock->wait_lock. Then unlock task->pi_lock. Now it is safe to refer to > > > lock. To avoid deadlocks I used _raw_spin_trylock() when locking the 2. > > > lock. > > > > Stupid me. I messed that one up. Should show up in the next -rt > > > > Thanks > > > > tglx > > > > > > - 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/