From owner-freebsd-current Fri Feb 18 14:24:25 2000 Delivered-To: freebsd-current@freebsd.org Received: from pcnet1.pcnet.com (pcnet1.pcnet.com [204.213.232.3]) by hub.freebsd.org (Postfix) with ESMTP id 2821F37BAB5 for ; Fri, 18 Feb 2000 14:24:22 -0800 (PST) (envelope-from eischen@vigrid.com) Received: (from eischen@localhost) by pcnet1.pcnet.com (8.8.7/PCNet) id RAA24508; Fri, 18 Feb 2000 17:24:08 -0500 (EST) Date: Fri, 18 Feb 2000 17:24:08 -0500 (EST) From: Daniel Eischen To: Matthew Dillon Cc: alc@cs.rice.edu, current@FreeBSD.ORG Subject: Re: tentitive complete patch for MAP_GUARDED available In-Reply-To: <200002182209.OAA81369@apollo.backplane.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 18 Feb 2000, Matthew Dillon wrote: > :Currently, the threads library only creates one guard page > :at the top (or bottom depending on how you look at it) of > :each threads stack (for stacks of default size). Thread > :stacks are allocated in sequential zones, so they are always > :placed on top of the previous threads stack, and thus already > :have a guard page below the stack. > : > :Correct me if I'm wrong, but using MAP_STACK|MAP_GUARDED > :would allocate one additional guard page for each threads > :stack. > : > :DanE. > > Correct. At the moment MAP_GUARDED is a 'generic' guarding flag > and makes no assumptions about the areas being adjoining. It doesn't > cost us anything. Any problem if we overlay a previously MAP_GUARDED page with another (to save an extra guard page)? Dan Eischen eischen@vigrid.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message