Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261768AbTIVW6U (ORCPT ); Mon, 22 Sep 2003 18:58:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261164AbTIVW6U (ORCPT ); Mon, 22 Sep 2003 18:58:20 -0400 Received: from fungus.teststation.com ([212.32.186.211]:11538 "EHLO fungus.teststation.com") by vger.kernel.org with ESMTP id S261768AbTIVW5G (ORCPT ); Mon, 22 Sep 2003 18:57:06 -0400 Date: Tue, 23 Sep 2003 00:57:04 +0200 (CEST) From: Urban Widmark X-X-Sender: puw@cola.enlightnet.local To: linux-kernel@vger.kernel.org Subject: semaphore IPC problem? Message-ID: 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: 1430 Lines: 45 Hello all I'm having a problem with IBM DB2 on linux. I found a page where IBM points fingers to the linux semaphore implementation, but without giving any details. "Information about the StaleConnectionException on Linux systems The StaleConnectionException SQl1224 is related to the extension shared memory attachment. Linux systems have a semaphore problem causing the DB2 SQL1224 error." http://publib7b.boulder.ibm.com/wasinfo1/en/info/aes/ae/rdat_stalelinux.html Does that make sense to anyone? Known semaphore problems/races? The page has a workaround which is to set it up as a remote database and connect over 127.0.0.1 instead of shm ipc. Doing that seems to work, but the setup is annoying. That it works could just be speed related, not sure if loopback is slower. The testcase is a number of threads (java) doing repeated select operations, with commit+close between each and using a connection pool. I have tested this on 2.4.22 (UP) and 2.6.0-test5. 2.6 can handle a lot more threads than 2.4 (~70 vs 3-5) before failing, but they both fail in the same way. I know I don't have much info ... Hints on where to look? (other than IBM support) /Urban - 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/