Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754489Ab1DROJG (ORCPT ); Mon, 18 Apr 2011 10:09:06 -0400 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:9910 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753177Ab1DROI5 (ORCPT ); Mon, 18 Apr 2011 10:08:57 -0400 X-IronPort-AV: E=Sophos;i="4.64,232,1301875200"; d="scan'208";a="5355988" Date: Mon, 18 Apr 2011 15:09:21 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball-desktop To: Stefano Stabellini CC: "H. Peter Anvin" , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" , "konrad.wilk@oracle.com" , "jeremy@goop.org" , "yinghai@kernel.org" , "mingo@elte.hu" Subject: Re: [PATCH 2/4] x86,xen: introduce x86_init.mapping.pagetable_reserve In-Reply-To: Message-ID: References: <1302607192-21355-2-git-send-email-stefano.stabellini@eu.citrix.com> <4DA5EAE4.2060406@linux.intel.com> <4DA70A4A.4030805@zytor.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1999 Lines: 52 On Thu, 14 Apr 2011, Stefano Stabellini wrote: > On Thu, 14 Apr 2011, H. Peter Anvin wrote: > > On 04/14/2011 04:30 AM, Stefano Stabellini wrote: > > > > > > I hope that the other email I have just sent clarifies the purpose of > > > the hook. > > > > > > > You're commingling rationale and (proposed) semantics. BOTH need to be > > stated clearly. > > Sorry I didn't answer the right question straight away. > The semantics follow: > > > > It is as if there is an implicit pvop after find_early_table_space > that exports the range pgt_buf_start - pgt_buf_top. > The range indicated is used, and it is the only range used, for the initial > kernel pagetable pages. > The range indicated is an overestimate. > It is implicit because we use the pgt_buf_* variables directly but > nonetheless it was in the first version of the patch. > > After the pagetable setup done by kernel_physical_mapping_init, we know > exactly how many pages we actually used for the initial kernel > pagetables and how many are left unused. > > The purpose of the second pvop (x86_init.mapping.pagetable_reserve) is > to notify sub-architectures of the actual range used for initial kernel > pagetable pages and partially revoke the previous indication. > > > > If you agree with the proposed semantics above, I'll add the description > to the commit message as well as the code. I could also modify the > syntax of the new pvop call to better suit the semantics and/or restore > the first pvop call. > ping? Sorry, I don't mean to be pushy, it is just that I'll be AFK for 12 days starting from next Friday and I think that this issue should really be fixed in time for the 2.6.39 release, otherwise no 2.6.39 kernels will be able to boot on any xen system. -- 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/