From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752886Ab3CRKxF (ORCPT ); Mon, 18 Mar 2013 06:53:05 -0400 Received: from cantor2.suse.de ([195.135.220.15]:34017 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751724Ab3CRKxC (ORCPT ); Mon, 18 Mar 2013 06:53:02 -0400 Date: Mon, 18 Mar 2013 11:52:57 +0100 From: Michal Hocko To: "K. Y. Srinivasan" Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, andi@firstfloor.org, akpm@linux-foundation.org, linux-mm@kvack.org, kamezawa.hiroyuki@gmail.com, hannes@cmpxchg.org, yinghan@google.com Subject: Re: [PATCH 2/2] Drivers: hv: balloon: Support 2M page allocations for ballooning Message-ID: <20130318105257.GG10192@dhcp22.suse.cz> References: <1363470088-24565-1-git-send-email-kys@microsoft.com> <1363470125-24606-1-git-send-email-kys@microsoft.com> <1363470125-24606-2-git-send-email-kys@microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1363470125-24606-2-git-send-email-kys@microsoft.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat 16-03-13 14:42:05, K. Y. Srinivasan wrote: > While ballooning memory out of the guest, attempt 2M allocations first. > If 2M allocations fail, then go for 4K allocations. In cases where we > have performed 2M allocations, split this 2M page so that we can free this > page at 4K granularity (when the host returns the memory). Maybe I am missing something but what is the advantage of 2M allocation when you split it up immediately so you are not using it as a huge page? [...] -- Michal Hocko SUSE Labs