From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Method execution failed Date: Fri, 06 Aug 2004 10:48:13 -0600 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <1091810893.3855.29.camel@tdi> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: acpi-devel List-Id: linux-acpi@vger.kernel.org I think there's a locking issue w/ namespace for concurrent calls to acpi_evaluate_object(). FWIW, these concurrent calls are coming in through my acpi sysfs patch, so it could be a bug in that code. If I serialize calls into acpi_evaluate_object(), it works fine, but I don't see a global lock for this, so I think the problem is more general. If I make lots of calls to evaluate the same _BBN object, I start seeing these: ACPI-0279: *** Error: Looking up [LBAS] in namespace, AE_ALREADY_EXISTS ACPI-1133: *** Error: Method execution failed [\LBA_.BBN_] (Node e00000407fd This starts at acpi_ds_load1_begin_op() doing a path lookup, presumably expecting not to find the path with flag ACPI_NS_ERROR_IF_FOUND. The AML for the method is: 0000000: a45c 2e4c 4241 5f42 424e 5f5e 5f55 4944 .\.LBA_BBN_^_UID The first part of the _SB/LBA/BBN_ AML looks like this: 0000000: 084c 4241 5311 030a 408a 4c42 4153 0056 .LBAS...@.LBAS.V 0000010: 414c 448a 4c42 4153 0a04 4c46 4c47 8a4c ALD.LBAS..LFLG.L ... The LBA/BBN_ method appears to make an object named LBAS. When calling this multiple times, each instance wants to not find this object and then create it. However, the namespace lock is given up around method execution, so it seems we have some races. Am I completely mis- interpreting the problem, or does this sound plausible? I don't really know how to read AML, so this is just a guess. Do we need to be more stringent on locking namespace, or is there a bug in the AML I'm calling? Thanks, Alex -- Alex Williamson HP Linux & Open Source Lab ------------------------------------------------------- This SF.Net email is sponsored by OSTG. Have you noticed the changes on Linux.com, ITManagersJournal and NewsForge in the past few weeks? Now, one more big change to announce. We are now OSTG- Open Source Technology Group. Come see the changes on the new OSTG site. www.ostg.com