From owner-freebsd-current@FreeBSD.ORG Wed Nov 29 22:49:45 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 086E416A407; Wed, 29 Nov 2006 22:49:45 +0000 (UTC) (envelope-from jb@what-creek.com) Received: from what-creek.com (what-creek.com [66.111.37.70]) by mx1.FreeBSD.org (Postfix) with ESMTP id AFDE743CC3; Wed, 29 Nov 2006 22:49:09 +0000 (GMT) (envelope-from jb@what-creek.com) Received: by what-creek.com (Postfix, from userid 102) id 63C23140EC03; Wed, 29 Nov 2006 22:50:25 +0000 (GMT) Date: Wed, 29 Nov 2006 22:50:25 +0000 From: John Birrell To: Scott Long Message-ID: <20061129225025.GA584@what-creek.com> References: <45622068.2050705@student.tue.nl> <200611291204.03716.jhb@freebsd.org> <20061129223221.GA359@what-creek.com> <456E0C66.4060404@samsco.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <456E0C66.4060404@samsco.org> User-Agent: Mutt/1.4.2.1i Cc: Rene Ladan , jb@freebsd.org, freebsd-current@freebsd.org Subject: Re: calcru-triggered panic? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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: Wed, 29 Nov 2006 22:49:45 -0000 On Wed, Nov 29, 2006 at 03:40:38PM -0700, Scott Long wrote: > It's probably less of an issue now that it used to be, since I/O is > decoupled through GEOM threads. In 4.x, you could have a stack that > went from the syscall, through VFS, UFS, the block layer, CAM, and > finally the device driver. When I was working on RAIDFrame, adding > just a couple hundred bytes of stack usage would cause it to blow out. > But as I said, it might not be as much of an issue now. Is it possible to check how deep the stack is and avoid using a stack buffer if too deep? -- John Birrell