From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754486AbbGaXU5 (ORCPT ); Fri, 31 Jul 2015 19:20:57 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:42439 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752501AbbGaXU4 (ORCPT ); Fri, 31 Jul 2015 19:20:56 -0400 Date: Sat, 1 Aug 2015 01:20:31 +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 08/10] xen/balloon: use hotplugged pages for foreign mappings etc. Message-ID: <20150731232031.GC3488@olila.local.net-space.pl> References: <1438275792-5726-1-git-send-email-david.vrabel@citrix.com> <1438275792-5726-9-git-send-email-david.vrabel@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1438275792-5726-9-git-send-email-david.vrabel@citrix.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 30, 2015 at 06:03:10PM +0100, David Vrabel wrote: > alloc_xenballooned_pages() is used to get ballooned pages to back > foreign mappings etc. Instead of having to balloon out real pages, > use (if supported) hotplugged memory. > > This makes more memory available to the guest and reduces > fragmentation in the p2m. > > This is only enabled if the xen.balloon.hotplug_unpopulated sysctl is > set to 1. This sysctl defaults to 0 in case the udev rules to > automatically online hotplugged memory do not exist. > > Signed-off-by: David Vrabel Reviewed-by: Daniel Kiper Daniel