From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 3 Jan 2001 11:33:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 3 Jan 2001 11:33:23 -0500 Received: from hermes.mixx.net ([212.84.196.2]:21519 "HELO hermes.mixx.net") by vger.kernel.org with SMTP id ; Wed, 3 Jan 2001 11:33:05 -0500 Message-ID: <3A534C78.55B1355E@innominate.de> Date: Wed, 03 Jan 2001 16:59:52 +0100 From: Daniel Phillips Organization: innominate X-Mailer: Mozilla 4.72 [de] (X11; U; Linux 2.4.0-prerelease i586) X-Accept-Language: en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Re: scheduling problem? In-Reply-To: <3A533C7D.A9C50DB@innominate.de> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Mike Galbraith wrote: > > On Wed, 3 Jan 2001, Daniel Phillips wrote: > > > Mike Galbraith wrote: > > > Semaphore timed out during boot, leaving bdflush as zombie. > > > > Wait a sec, what do you mean by 'semaphore timed out'? These should > > wait patiently forever. > > IKD has a semaphore deadlock detector. That was my tentative conclusion. > Any place you take a semaphore > and have to wait longer than 5 seconds (what I had it set to because > with trace buffer set to 3000000 entries, it can only cover ~8 seconds > of disk [slowest] load), it triggers and freezes the trace buffer for > later use. It firing under load may not be of interest. (but it firing > looks to be very closly coupled to observed stalls with virgin source. > Linus fixes big stall and deadlock detector mostly shuts up. I fix a > smaller stall and it shuts up entirely.. for this workload) But it's entirely legal for a semaphore to wait forever when used in the way I've used them, a producer/consumer pattern. You should be able to run happily (at least as happily as before) with the watchdog disabled. This begs the question of what to do about the 99.99% of cases where the watchdog is a good thing to have. Shouldn't the watchdog just log the 'suspicious' event and continue? -- Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/