From owner-freebsd-current Thu Feb 4 09:49:55 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA23174 for freebsd-current-outgoing; Thu, 4 Feb 1999 09:49:55 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA23168 for ; Thu, 4 Feb 1999 09:49:54 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.2/8.9.1) id JAA89484; Thu, 4 Feb 1999 09:49:50 -0800 (PST) (envelope-from dillon) Date: Thu, 4 Feb 1999 09:49:50 -0800 (PST) From: Matthew Dillon Message-Id: <199902041749.JAA89484@apollo.backplane.com> To: Matthew Dillon Cc: Stephen McKay , freebsd-current@FreeBSD.ORG, syssgm@detir.qld.gov.au Subject: Re: panic: vm_object_qcollapse(): object mismatch References: <199902041300.XAA10590@nymph.detir.qld.gov.au> <199902041726.JAA88650@apollo.backplane.com> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I introduced this bug in 1.139 when I added the KASSERT(). Bleh. However, the code still needs to be protected at splbio(). And so I've committed. -Matt : Hmmm. This looks like an out-an-out bug to me. The assertion is wrong. : It's scanning the backing_object and asserting that the pages in the : backing object are associated with object rather then backing_object. : : This section of code only runs when paging is in progress on a : collapseable object AND there are also idle pages in that object. : The collapse condition is probably due to an exiting process ( typical : in a buildworld ). : : ( from vm/vm_object.c ) : /* : * busy the page and move it from the backing store to the : * parent object. : */ : : vm_page_busy(p); : : KASSERT(p->object == object, ("vm_object_qcollapse(): object mismatch")); : ^^^^^^^^^^ : should be 'backing_object' : : There is also an interrupt race. Since paging can be in progress, : pages in the object can be ripped out from under it so we have to : run at splbio() in the loop. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message