From owner-freebsd-threads@FreeBSD.ORG  Mon Jun 16 22:35:07 2003
Return-Path: <owner-freebsd-threads@FreeBSD.ORG>
Delivered-To: freebsd-threads@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id B440237B401
	for <threads@freebsd.org>; Mon, 16 Jun 2003 22:35:07 -0700 (PDT)
Received: from heron.mail.pas.earthlink.net (heron.mail.pas.earthlink.net
	[207.217.120.189])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 2C0D243F75
	for <threads@freebsd.org>; Mon, 16 Jun 2003 22:35:07 -0700 (PDT)
	(envelope-from tlambert2@mindspring.com)
Received: from user-2injaq3.dialup.mindspring.com ([165.121.171.67]
	helo=mindspring.com)
	by heron.mail.pas.earthlink.net with asmtp (SSLv3:RC4-MD5:128)
	(Exim 3.33 #1)	id 19S97X-00000h-00; Mon, 16 Jun 2003 22:35:04 -0700
Message-ID: <3EEEA846.DD3F3C7B@mindspring.com>
Date: Mon, 16 Jun 2003 22:33:58 -0700
From: Terry Lambert <tlambert2@mindspring.com>
X-Mailer: Mozilla 4.79 [en] (Win98; U)
X-Accept-Language: en
MIME-Version: 1.0
To: Gareth Hughes <gareth@nvidia.com>
References: <2D32959E172B8F4D9B02F68266BE421401A6D7D1@mail-sc-3.nvidia.com>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-ELNK-Trace: b1a02af9316fbb217a47c185c03b154d40683398e744b8a4d71d00f4e433a515d330d0b32798e4aa350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c
cc: threads@freebsd.org
cc: zander@mail.minion.de
cc: 'Julian Elischer' <julian@elischer.org>
cc: Andy Ritger <ARitger@nvidia.com>
cc: Daniel Eischen <eischen@pcnet.com>
Subject: Re: NVIDIA and TLS
X-BeenThere: freebsd-threads@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Threading on FreeBSD <freebsd-threads.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-threads>,
	<mailto:freebsd-threads-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-threads>
List-Post: <mailto:freebsd-threads@freebsd.org>
List-Help: <mailto:freebsd-threads-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-threads>,
	<mailto:freebsd-threads-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 17 Jun 2003 05:35:08 -0000

Gareth Hughes wrote:
> Or, better yet, to make sure no problems arise when you change the internals
> of your data structures:
> 
> %gs ----->[libGL stuff (16 words, say)      ]
>           [threadsystem-thread-specific-data]
>           [ stuff                           ]
> 
> You reserve the first 16 words of your thread data structure for us, and
> we're done.  At least when this library is being used.

This would really suck on most systems because of the cache
line misses.  The thread specific data for the threading
system wants to be in a cache line aligned memory location,
and not exceed a cache line in length.

You are running multiple threads: surely it's more important,
in general, for threads context switch to be fast from your
perspective?

-- Terry