From owner-freebsd-current  Wed Feb 16 14:14: 7 2000
Delivered-To: freebsd-current@freebsd.org
Received: from builder.freebsd.org (builder.FreeBSD.ORG [204.216.27.24])
	by hub.freebsd.org (Postfix) with ESMTP id 72A4F37B505
	for <current@FreeBSD.org>; Wed, 16 Feb 2000 14:14:05 -0800 (PST)
	(envelope-from jasone@canonware.com)
Received: from canonware.com (canonware.com [207.20.242.18])
	by builder.freebsd.org (Postfix) with SMTP id 248EA132D6
	for <current@FreeBSD.org>; Wed, 16 Feb 2000 14:13:27 -0800 (PST)
Received: (qmail 21752 invoked by uid 1001); 16 Feb 2000 22:13:39 -0000
Date: Wed, 16 Feb 2000 14:13:39 -0800
From: Jason Evans <jasone@canonware.com>
To: Matthew Dillon <dillon@apollo.backplane.com>
Cc: current@FreeBSD.org
Subject: Re: Heads up, vm.max_proc_mmap sysctl added
Message-ID: <20000216141339.C18774@sturm.canonware.com>
References: <200002162118.NAA54097@apollo.backplane.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Mailer: Mutt 1.0.1i
In-Reply-To: <200002162118.NAA54097@apollo.backplane.com>; from dillon@apollo.backplane.com on Wed, Feb 16, 2000 at 01:18:13PM -0800
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

On Wed, Feb 16, 2000 at 01:18:13PM -0800, Matthew Dillon wrote:
>     This deals with a mmap+fork bomb that can cause the kernel to 
>     eat all of KVM in vm_map_entry structures.  The default limit
>     should be set generously enough for people using the current
>     FreeBSD threads incarnation (and isn't an issue w/ linux
>     threads due to rfork resulting in scaling of the limit for the
>     shared address space).
> 
>     Heads up in case a heavy threads programmer sees something I missed.

Note that thread stack allocation in libc_r also uses mmap() (one region
per thread), so this applies there as well.

Jason


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message