From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751203AbWH3Rcq (ORCPT ); Wed, 30 Aug 2006 13:32:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751207AbWH3Rcq (ORCPT ); Wed, 30 Aug 2006 13:32:46 -0400 Received: from ns1.suse.de ([195.135.220.2]:57998 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751203AbWH3Rcp (ORCPT ); Wed, 30 Aug 2006 13:32:45 -0400 From: Andi Kleen To: Jeremy Fitzhardinge Subject: Re: [PATCH RFC 0/6] Implement per-processor data areas for i386. Date: Wed, 30 Aug 2006 19:32:38 +0200 User-Agent: KMail/1.9.3 Cc: Chuck Ebbert <76306.1226@compuserve.com>, linux-kernel , Zachary Amsden , Jan Beulich , Andrew Morton References: <200608300838_MC3-1-C9C6-CA79@compuserve.com> <200608301848.39443.ak@suse.de> <44F5C73F.2060308@goop.org> In-Reply-To: <44F5C73F.2060308@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200608301932.38359.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 30 August 2006 19:13, Jeremy Fitzhardinge wrote: > Andi Kleen wrote: > > I tried that once on x86-64, but it wasn't possible because the linker > > is missing the right relocations. It has something on the first look similar > > for __thread data in user space, but it wasn't usable for the kernel. > > > The other difficulty is that you can't take the addresses of things in > the pda and pass them around, which happens a lot. The user space __thread works around this by always storing the address at offset 0. Kernel does it similar, except it's not at offset 0. > (Hm, it would be interesting to see if we could possibly use the code > generated by gcc for TLS variables...) I tried once on 64bit and it wasn't possible for various reasons. -Andi