From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754480AbbGaXYE (ORCPT ); Fri, 31 Jul 2015 19:24:04 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:18735 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753098AbbGaXYB (ORCPT ); Fri, 31 Jul 2015 19:24:01 -0400 Date: Sat, 1 Aug 2015 01:23:50 +0200 From: Daniel Kiper To: David Vrabel Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, linux-mm@kvack.org, Konrad Rzeszutek Wilk , Boris Ostrovsky Subject: Re: [PATCHv3 10/10] xen/balloon: pre-allocate p2m entries for ballooned pages Message-ID: <20150731232350.GE3488@olila.local.net-space.pl> References: <1438275792-5726-1-git-send-email-david.vrabel@citrix.com> <1438275792-5726-11-git-send-email-david.vrabel@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1438275792-5726-11-git-send-email-david.vrabel@citrix.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 30, 2015 at 06:03:12PM +0100, David Vrabel wrote: > Pages returned by alloc_xenballooned_pages() will be used for grant > mapping which will call set_phys_to_machine() (in PV guests). > > Ballooned pages are set as INVALID_P2M_ENTRY in the p2m and thus may > be using the (shared) missing tables and a subsequent > set_phys_to_machine() will need to allocate new tables. > > Since the grant mapping may be done from a context that cannot sleep, > the p2m entries must already be allocated. > > Signed-off-by: David Vrabel Reviewed-by: Daniel Kiper Daniel PS FYI, next week I am on vacation.