From owner-cvs-all@FreeBSD.ORG  Sat Aug 21 23:31:35 2004
Return-Path: <owner-cvs-all@FreeBSD.ORG>
Delivered-To: cvs-all@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id BFFBB16A4CE; Sat, 21 Aug 2004 23:31:35 +0000 (GMT)
Received: from cs.rice.edu (cs.rice.edu [128.42.1.30])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id A604D43D2F; Sat, 21 Aug 2004 23:31:35 +0000 (GMT)
	(envelope-from alc@cs.rice.edu)
Received: from localhost (calypso.cs.rice.edu [128.42.1.127])
	by cs.rice.edu (Postfix) with ESMTP id 5FFB24ABAA;
	Sat, 21 Aug 2004 18:31:35 -0500 (CDT)
Received: from cs.rice.edu ([128.42.1.30])
 by localhost (calypso.cs.rice.edu [128.42.1.127]) (amavisd-new, port 10024)
 with LMTP id 30425-01-30; Sat, 21 Aug 2004 18:31:35 -0500 (CDT)
Received: by cs.rice.edu (Postfix, from userid 19572)
	id 0B58B4ABA7; Sat, 21 Aug 2004 18:31:35 -0500 (CDT)
Date: Sat, 21 Aug 2004 18:31:34 -0500
From: Alan Cox <alc@cs.rice.edu>
To: Brian Fundakowski Feldman <green@FreeBSD.org>
Message-ID: <20040821233134.GF9106@cs.rice.edu>
References: <200408211920.i7LJKLlA088634@repoman.freebsd.org>
	<20040821225939.GA784@green.homeunix.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20040821225939.GA784@green.homeunix.org>
User-Agent: Mutt/1.4.2i
X-Virus-Scanned: by amavis-20030616-p7 at cs.rice.edu
cc: Alan Cox <alc@FreeBSD.org>
cc: cvs-src@FreeBSD.org
cc: src-committers@FreeBSD.org
cc: cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/vm vm_fault.c
X-BeenThere: cvs-all@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: CVS commit messages for the entire tree <cvs-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-all>,
	<mailto:cvs-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/cvs-all>
List-Post: <mailto:cvs-all@freebsd.org>
List-Help: <mailto:cvs-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-all>,
	<mailto:cvs-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 21 Aug 2004 23:31:35 -0000

On Sat, Aug 21, 2004 at 06:59:39PM -0400, Brian Fundakowski Feldman wrote:
> On Sat, Aug 21, 2004 at 07:20:21PM +0000, Alan Cox wrote:
> > alc         2004-08-21 19:20:21 UTC
> > 
> >   FreeBSD src repository
> > 
> >   Modified files:
> >     sys/vm               vm_fault.c 
> >   Log:
> >   Further reduce the use of Giant by vm_fault(): Giant is held only when
> >   manipulating a vnode, e.g., calling vput().  This reduces contention for
> >   Giant during many copy-on-write faults, resulting in some additional
> >   speedup on SMPs.
> >   
> >   Note: debug_mpsafevm must be enabled for this optimization to take effect.
> 
> This is very broken.  See included first attempt at fixing it without
> regard for actually trying to reimplement debug.mpsafenet for vnodes.
> 

Can you please explain what is broken?

Alan