From owner-freebsd-current@FreeBSD.ORG Sat Jan 17 11:03:10 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A9DD216A4CE for ; Sat, 17 Jan 2004 11:03:10 -0800 (PST) Received: from tx1.oucs.ox.ac.uk (tx1.oucs.ox.ac.uk [129.67.1.167]) by mx1.FreeBSD.org (Postfix) with ESMTP id A8F3543D53 for ; Sat, 17 Jan 2004 11:03:08 -0800 (PST) (envelope-from colin.percival@wadham.ox.ac.uk) Received: from scan1.oucs.ox.ac.uk ([129.67.1.166] helo=localhost) by tx1.oucs.ox.ac.uk with esmtp (Exim 4.20) id 1Ahvit-00074S-IA for freebsd-current@freebsd.org; Sat, 17 Jan 2004 19:03:07 +0000 Received: from rx1.oucs.ox.ac.uk ([129.67.1.165]) by localhost (scan1.oucs.ox.ac.uk [129.67.1.166]) (amavisd-new, port 25) with ESMTP id 27165-01 for ; Sat, 17 Jan 2004 19:03:07 +0000 (GMT) Received: from gateway.wadham.ox.ac.uk ([163.1.161.253]) by rx1.oucs.ox.ac.uk with smtp (Exim 4.20) id 1Ahviq-0006z9-4o for freebsd-current@freebsd.org; Sat, 17 Jan 2004 19:03:04 +0000 Received: (qmail 28356 invoked by uid 0); 17 Jan 2004 19:03:04 -0000 Received: from colin.percival@wadham.ox.ac.uk by gateway by uid 71 with qmail-scanner-1.16 (sweep: 2.14/3.71. spamassassin: 2.53. Clear:. Processed in 4.071081 secs); 17 Jan 2004 19:03:04 -0000 X-Qmail-Scanner-Mail-From: colin.percival@wadham.ox.ac.uk via gateway X-Qmail-Scanner: 1.16 (Clear:. Processed in 4.071081 secs) Received: from dhcp1131.wadham.ox.ac.uk (HELO piii600.wadham.ox.ac.uk) (163.1.161.131) by gateway.wadham.ox.ac.uk with SMTP; 17 Jan 2004 19:02:59 -0000 Message-Id: <6.0.1.1.1.20040117185104.02bd9f88@imap.sfu.ca> X-Sender: cperciva@imap.sfu.ca (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 6.0.1.1 Date: Sat, 17 Jan 2004 19:02:58 +0000 To: Peter Wood From: Colin Percival In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed cc: freebsd-current@freebsd.org Subject: Re: FreeBSD 5.2R+C: panic: kmem_malloc(4096): kmem_map too small X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Jan 2004 19:03:10 -0000 At 17:25 17/01/2004, Peter Wood wrote: >I have come accross a reproducable panic in bother 5.2-Release and 5.2-Current >(as it was an hour ago). To perform this, I create two 750Mb memory disks, >format them and mount them. Quote from the mdconfig(8) man page: > malloc Storage for this type of memory disk is allocated with > malloc(9). This limits the size to the malloc bucket > limit in the kernel. If the -o reserve option is not > set, creating and filling a large malloc-backed memory > disk is a very easy way to panic a system. It doesn't look like this is going to be fixed any time soon -- see the discussion under pr kern/53350 -- so for now the answer is simply "don't do that". Colin Percival