From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Seifert Subject: Re: mutexes and preemption Date: Thu, 4 Mar 2004 11:22:12 +0100 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20040304102212.GA2303@ergo.gotdns.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: "Moore, Robert" Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, "Grover, Andrew" , "Therien, Guy" , "Brown, Len" , "Yu, Luming" List-Id: linux-acpi@vger.kernel.org On Wed, Mar 03, 2004 at 05:08:53PM -0800, Moore, Robert wrote: > > Looking at the timestamps in the debug output, I suspect that the real > issue here is this line: > > Mar 2 23:03:10 tenshi kernel: osl-0909 [2049] os_wait_semaphore > : Failed to acquire semaphore[dffd8680|1|36863], AE_TIME > > Because this wait should have been for 37 seconds (36863 milliseconds), > yet not one second has gone by on the wall clock. > > A close look at the Linux implementation of os_wait_semaphore may again > be in order. You are right, thank you. I believe there is a bug in os_wait_semaphore: the return value of down_trylock isn't checked correctly, leading to the immediate failure of an Acquire with timeout in the case the semaphore cannot be acquired immediately . I've sent a patch to this list. I hope someone applies it. Sebastian -- A bad analogy is like leaky screwdriver. ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click