From owner-freebsd-bugs@FreeBSD.ORG Wed Nov 5 14:40:11 2003 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 90A7016A4CE for ; Wed, 5 Nov 2003 14:40:11 -0800 (PST) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 186D443FEA for ; Wed, 5 Nov 2003 14:40:09 -0800 (PST) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.12.9/8.12.9) with ESMTP id hA5Me8FY024192 for ; Wed, 5 Nov 2003 14:40:08 -0800 (PST) (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.12.9/8.12.9/Submit) id hA5Me8Fx024191; Wed, 5 Nov 2003 14:40:08 -0800 (PST) (envelope-from gnats) Resent-Date: Wed, 5 Nov 2003 14:40:08 -0800 (PST) Resent-Message-Id: <200311052240.hA5Me8Fx024191@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Doug White Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5398B16A4CE for ; Wed, 5 Nov 2003 14:37:40 -0800 (PST) Received: from carver.gumbysoft.com (carver.gumbysoft.com [66.220.23.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6BEA043FDD for ; Wed, 5 Nov 2003 14:37:39 -0800 (PST) (envelope-from dwhite@gumbysoft.com) Received: by carver.gumbysoft.com (Postfix, from userid 1000) id 5D74272DB8; Wed, 5 Nov 2003 14:37:39 -0800 (PST) Message-Id: <20031105223739.5D74272DB8@carver.gumbysoft.com> Date: Wed, 5 Nov 2003 14:37:39 -0800 (PST) From: Doug White To: FreeBSD-gnats-submit@FreeBSD.org X-Send-Pr-Version: 3.113 Subject: kern/58984: SYSV Semaphore exhaustion causes Giant deadlock X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: Doug White List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Nov 2003 22:40:11 -0000 >Number: 58984 >Category: kern >Synopsis: SYSV Semaphore exhaustion causes Giant deadlock >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Nov 05 14:40:08 PST 2003 >Closed-Date: >Last-Modified: >Originator: Doug White >Release: FreeBSD 5.1-CURRENT i386 >Organization: >Environment: FreeBSD fbtest1.looksmart.com 5.1-CURRENT FreeBSD 5.1-CURRENT #6: Wed Nov 5 12:10:15 PST 2003 root@fbtest1.looksmart.com:/usr/src/sys/i386/compile/XEON i386 >Description: Depletion the system of SYSV semaphores causes the semop() system call to infinitely retry to allocate resources while holding Giant. This causes a complete system hang. The tracebacks I get when I break into ddb usually are in semundo_adjust(). >How-To-Repeat: In our environment, I was able to duplicate this using 2 2.4GHz Xeon systems, one serving as a httpd/php host with the pear-APC module installed, and the other as a load generator. pear-APC uses SYSV semaphores to control access to its shared code cache. The client is using ApacheBench to hit a php script on the server. If ab is run with more than 15 clients, the system hangs less than a second after the bench begins. >Fix: >Release-Note: >Audit-Trail: >Unformatted: