Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932704AbVLHXLr (ORCPT ); Thu, 8 Dec 2005 18:11:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932705AbVLHXLr (ORCPT ); Thu, 8 Dec 2005 18:11:47 -0500 Received: from mail.suse.de ([195.135.220.2]:15034 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S932704AbVLHXLr (ORCPT ); Thu, 8 Dec 2005 18:11:47 -0500 Date: Fri, 9 Dec 2005 00:11:41 +0100 From: Andi Kleen To: Rohit Seth Cc: Ravikiran G Thirumalai , Andi Kleen , Andrew Morton , linux-kernel@vger.kernel.org, discuss@x86-64.org, zach@vmware.com, shai@scalex86.org, nippung@calsoftinc.com Subject: Re: [discuss] [patch] x86_64: align and pad x86_64 GDT on page boundary Message-ID: <20051208231141.GX11190@wotan.suse.de> References: <20051208215514.GE3776@localhost.localdomain> <1134083357.7131.21.camel@akash.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1134083357.7131.21.camel@akash.sc.intel.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1369 Lines: 36 On Thu, Dec 08, 2005 at 03:09:17PM -0800, Rohit Seth wrote: > On Thu, 2005-12-08 at 13:55 -0800, Ravikiran G Thirumalai wrote: > > On Thu, Dec 08, 2005 at 09:15:18PM +0100, Andi Kleen wrote: > > > On Thu, Dec 08, 2005 at 11:42:32AM -0800, Ravikiran G Thirumalai > > wrote: > > > > > > > > - .align L1_CACHE_BYTES > > > > + /* zero the remaining page */ > > > > + .fill PAGE_SIZE / 8 - GDT_ENTRIES,8,0 > > > > + > > > > ENTRY(idt_table) > > > > > > Why can't the IDT not be shared with the GDT page? It should be > > mostly > > > read only right and putting r-o data on that page should be ok, > > right? > > > > Yes, you are right. This should not have been a problem. > > Some people reported this symbol (cpu_gdt) though. Will have to go > > back and > > check. > > IIRC, Zach's patches for gdt alignment, moved the gdts from per_cpu data > structure to each secondary CPU dynamically allocating page for its gdt. Kiran's patch does this too. Except for the BP GDT, which could be shared with the single IDT. -Andi (who actually plans to attack per CPU IDTs at some point so this could change later) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/