From owner-freebsd-alpha  Sat Dec 14 17:28:47 2002
Delivered-To: freebsd-alpha@freebsd.org
Received: from green.bikeshed.org (freefall.freebsd.org [216.136.204.21])
	by hub.freebsd.org (Postfix) with ESMTP
	id 4E70137B401; Sat, 14 Dec 2002 17:28:46 -0800 (PST)
Received: from green.bikeshed.org (s392h93sobxhikr7@green.bikeshed.org [10.0.0.1] (may be forged))
	by green.bikeshed.org (8.12.6/8.12.6) with ESMTP id gBF1SjOa014366;
	Sat, 14 Dec 2002 20:28:45 -0500 (EST)
	(envelope-from green@green.bikeshed.org)
Received: from localhost (green@localhost)
	by green.bikeshed.org (8.12.6/8.12.6/Submit) with ESMTP id gBF1SjS2014362;
	Sat, 14 Dec 2002 20:28:45 -0500 (EST)
Message-Id: <200212150128.gBF1SjS2014362@green.bikeshed.org>
X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4
To: Matthew Dillon <dillon@apollo.backplane.com>
Cc: Jake Burkholder <jake@locore.ca>,
	"Brian F. Feldman" <green@FreeBSD.ORG>,
	John Baldwin <jhb@FreeBSD.ORG>, Kris Kennaway <kris@obsecurity.org>,
	current@FreeBSD.ORG, alpha@FreeBSD.ORG
Subject: Re: UMA panic under load 
In-Reply-To: Your message of "Sat, 14 Dec 2002 17:10:38 PST."
             <200212150110.gBF1AcB6060179@apollo.backplane.com> 
From: "Brian F. Feldman" <green@FreeBSD.ORG>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Sat, 14 Dec 2002 20:28:45 -0500
Sender: owner-freebsd-alpha@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-alpha.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-alpha>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-alpha>
X-Loop: FreeBSD.org

Matthew Dillon <dillon@apollo.backplane.com> wrote:
>     What about something like this.  If the vm_refcnt is still being
>     decremented too early, could it be moved to just before the thread_exit()
>     call?

The problem that had to be fixed by removing this race was that two 
processes with the same vmspace can exit at the same time, and the 
vm_refcnt could be 2 the entire time, so neither would perform the current
if (--vm->vm_refcnt == 0) { block.

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green@FreeBSD.org  <> bfeldman@tislabs.com      \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\



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