From owner-cvs-all@FreeBSD.ORG Fri Jun 17 17:46:59 2005 Return-Path: X-Original-To: cvs-all@FreeBSD.org Delivered-To: cvs-all@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D47DD16A41C; Fri, 17 Jun 2005 17:46:59 +0000 (GMT) (envelope-from alc@cs.rice.edu) Received: from cs.rice.edu (cs.rice.edu [128.42.1.30]) by mx1.FreeBSD.org (Postfix) with ESMTP id AC0D943D1D; Fri, 17 Jun 2005 17:46:59 +0000 (GMT) (envelope-from alc@cs.rice.edu) Received: from localhost (calypso.cs.rice.edu [128.42.1.127]) by cs.rice.edu (Postfix) with ESMTP id 268DB4A9A3; Fri, 17 Jun 2005 12:46:59 -0500 (CDT) Received: from cs.rice.edu ([128.42.1.30]) by localhost (calypso.cs.rice.edu [128.42.1.127]) (amavisd-new, port 10024) with LMTP id 07178-01-86; Fri, 17 Jun 2005 12:46:58 -0500 (CDT) Received: by cs.rice.edu (Postfix, from userid 19572) id 9C94C4A9A0; Fri, 17 Jun 2005 12:46:58 -0500 (CDT) Date: Fri, 17 Jun 2005 12:46:58 -0500 From: Alan Cox To: David O'Brien Message-ID: <20050617174658.GK5251@cs.rice.edu> References: <200506161706.j5GH6YgW038252@repoman.freebsd.org> <20050617063914.GA1097@dragon.NUXI.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050617063914.GA1097@dragon.NUXI.org> User-Agent: Mutt/1.4.2i X-Virus-Scanned: by amavis-2.2.1 at cs.rice.edu Cc: Alan Cox , cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/vm uma_int.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Jun 2005 17:47:00 -0000 On Thu, Jun 16, 2005 at 11:39:14PM -0700, David O'Brien wrote: > On Thu, Jun 16, 2005 at 05:06:34PM +0000, Alan Cox wrote: > > alc 2005-06-16 17:06:34 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/vm uma_int.h > > Log: > > Increase UMA_BOOT_PAGES to prevent a crash during initialization. See > > http://docs.FreeBSD.org/cgi/mid.cgi?42AD8270.8060906 for a detailed > > description of the crash. > > Today, I finally got a traceback of my insta-reboots after marius' atkbd > commit (2005-06-10 20:56:38 UTC) and it was exactly this same traceback. > Funny that such an innocuous commit started causing my 'i386' workstation > to panic. We were that much on the edge of having enough UMA_BOOT_PAGES? > Is 48 enough? I recall that 42 was the minimum to fix Eric's panic. I chose 48 so that we would have some space to spare. > It looks like the code attempts to help the poor user out: > sys/vm/uma_core.c:911: panic("UMA: Increase UMA_BOOT_PAGES"); > But why wasn't that being triggered in Eric Anderson's case and mine? My untested understanding of this problem has two parts. (1) UMA has completed its own internal boot sequence. Hence, the Boolean "booted" is set to TRUE and the above panic does not occur. (2) However, the VM system has not completed its overall initialization. Specifically, the call to vm_init2() has not been performed. Hence, the correct allocator for the kernel address space's map entry zone has not been set and any attempt to allocate a kernel map entry that is not satisfiable from boot pages results in a panic. Alan