From owner-freebsd-hackers Tue Apr 9 10:11:51 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from artemis.drwilco.net (diana.drwilco.net [66.48.127.79]) by hub.freebsd.org (Postfix) with ESMTP id 987D237B419 for ; Tue, 9 Apr 2002 10:11:48 -0700 (PDT) Received: from ceres.drwilco.net (docwilco.xs4all.nl [213.84.68.230]) by artemis.drwilco.net (8.11.6/8.11.6) with ESMTP id g39HB5x31619 (using TLSv1/SSLv3 with cipher DES-CBC3-SHA (168 bits) verified NO); Tue, 9 Apr 2002 13:11:08 -0400 (EDT) (envelope-from drwilco@drwilco.net) Message-Id: <5.1.0.14.0.20020409192018.01c667a0@mail.drwilco.net> X-Sender: lists@mail.drwilco.net X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Tue, 09 Apr 2002 19:23:40 +0200 To: Terry Lambert , callum.gibson@db.com From: "Rogier R. Mulhuijzen" Subject: Re: ipcrm/shmctl failure Cc: hackers@FreeBSD.ORG In-Reply-To: <3CB276CB.89703872@mindspring.com> References: <20020408225938.2069.qmail@merton.aus.deuba.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG At 22:06 8-4-2002 -0700, Terry Lambert wrote: >All you are doing is marking the segment as removed. The segment >remains attached by the processes which have it open, and those >references don't go awaya until the processes in question detach >the segments, and the reference count goes to zero. >It turns out that these segments are not proerly reference >counted and tracked, so they are not deleted when the client >"goes away". > >This is a bug in the MIT shared memory extension for X design, >and can't be fixed for long running programs with lots of >bitmaps. I'd like to take a step further and say it's in SYSVSHM design. All a program has to do is forget to do a shm_detach() and you're f#$%ed. Be glad it's just a few bitmaps, and not a 250 meg segment like I had with a certain version of Oracle. >It's an X11 question, and it's been that way since at least 1994, >so it's a long standing X11 FAQ. You could say that X11 shouldn't use SHMs the way it does now yeah. =) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message