From owner-freebsd-arch@FreeBSD.ORG Sun Sep 30 18:45:49 2007 Return-Path: <owner-freebsd-arch@FreeBSD.ORG> Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CEC8116A41A; Sun, 30 Sep 2007 18:45:49 +0000 (UTC) (envelope-from bright@elvis.mu.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id 4B6CA13C447; Sun, 30 Sep 2007 18:45:49 +0000 (UTC) (envelope-from bright@elvis.mu.org) Received: by elvis.mu.org (Postfix, from userid 1192) id 759BF1A4D80; Sun, 30 Sep 2007 11:24:27 -0700 (PDT) Date: Sun, 30 Sep 2007 11:24:27 -0700 From: Alfred Perlstein <alfred@freebsd.org> To: Alexander Motin <mav@FreeBSD.org> Message-ID: <20070930182427.GY53439@elvis.mu.org> References: <46FFD850.1040508@FreeBSD.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46FFD850.1040508@FreeBSD.org> User-Agent: Mutt/1.4.2.3i Cc: freebsd-arch@freebsd.org Subject: Re: Kernel thread stack usage X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture <freebsd-arch.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>, <mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch> List-Post: <mailto:freebsd-arch@freebsd.org> List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help> List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>, <mailto:freebsd-arch-request@freebsd.org?subject=subscribe> X-List-Received-Date: Sun, 30 Sep 2007 18:45:49 -0000 * Alexander Motin <mav@FreeBSD.org> [070930 11:09] wrote: > Hi. > > As known in netgraph susbystem information passing from one node to > another by direct function calls without queueing. It gives performance > bonuses, but it also gives permanent stack overflow risk on complicated > graphs. Netgraph is still have a queues and able to use them when asked, > but now queueing is a flag which should be controlled by sending node. I > think it would be good to implement some algorithm which could monitor > stack usage on each call and enforce queueing when stack usage become > critical. > > The question is: is there correct way to somehow get current kernel > thread stack usage or just a stack base address? Not that I know of, but one could defer to queueing once the chain gets to a certain length. -- - Alfred Perlstein