From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 20 Aug 2007 09:10:08 +0100 (BST) Received: from phoenix.bawue.net ([193.7.176.60]:17331 "EHLO mail.bawue.net") by ftp.linux-mips.org with ESMTP id S20021586AbXHTIKG (ORCPT ); Mon, 20 Aug 2007 09:10:06 +0100 Received: from lagash (intrt.mips-uk.com [194.74.144.130]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.bawue.net (Postfix) with ESMTP id 88566B83D6; Mon, 20 Aug 2007 10:06:25 +0200 (CEST) Received: from ths by lagash with local (Exim 4.67) (envelope-from ) id 1IN2HL-0006L8-3O; Mon, 20 Aug 2007 09:06:27 +0100 Date: Mon, 20 Aug 2007 09:06:27 +0100 From: Thiemo Seufer To: Carl van Schaik Cc: linux-mips@linux-mips.org Subject: Re: TLS register for NPTL Message-ID: <20070820080627.GF4479@networkno.de> References: <46C93BB5.9050809@ok-labs.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46C93BB5.9050809@ok-labs.com> User-Agent: Mutt/1.5.16 (2007-06-11) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 16220 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ths@networkno.de Precedence: bulk X-list: linux-mips Carl van Schaik wrote: > Hi All, > > It seems the rdhwr emulation is used/proposed for accessing the thread > word in NPTL. > I've been reading some of the posts from 2005 about this choice of this > and what I have missed is anyone talking about using the "k0" register > for TLS. It seems logical that the kernel could always restore k0 on > returning to user-land and having k1 only for the last part of returning > to user is sufficient. Any reason why this was not looked at? The TLB handlers need k0/k1 as well and have no good place to save/restore a register. Thiemo