From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752248Ab1I0RHE (ORCPT ); Tue, 27 Sep 2011 13:07:04 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:55671 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751790Ab1I0RHD (ORCPT ); Tue, 27 Sep 2011 13:07:03 -0400 X-IronPort-AV: E=Sophos;i="4.68,450,1312171200"; d="scan'208";a="164838942" Message-ID: <4E820316.6070101@citrix.com> Date: Tue, 27 Sep 2011 18:08:38 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20110818 Icedove/3.0.11 MIME-Version: 1.0 To: Dan Magenheimer CC: Konrad Wilk , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" , Jeremy Fitzhardinge Subject: Re: [PATCH v2] xen: Fix selfballooning and ensure it doesn't go too far References: <2de59b55-4ecc-4155-8709-f8b0f5e012bc@default 4E81F278.5040107@citrix.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/09/11 17:19, Dan Magenheimer wrote: >> From: David Vrabel [mailto:david.vrabel@citrix.com] >> Subject: Re: [PATCH v2] xen: Fix selfballooning and ensure it doesn't go too far >> >> On 27/09/11 16:03, Dan Magenheimer wrote: >>> Note: This patch is also now in a git tree at: >>> >>> git://oss.oracle.com/git/djm/tmem.git#selfballoon-fix-v2 >>> >>> The balloon driver's "current_pages" is very different from >>> totalram_pages. Self-ballooning needs to be driven by >>> the latter. > > Hi David -- > > Thanks for the feedback! > >> I don't think this part of the change makes any difference. It looks like it >> rearranges the maths without changing the end result (other than >> slightly increasing the rate of change). >> I think this (partial, untested) patch is equivalent: > > Actually it does. Really? Both patched and unpatched the new target, S, is (eventually): S = V + F + C - T where V is vm_committed_as, F is frontswap_curr_pages(), C is balloon_stats.current_pages, and T = totalram_pages. Perhaps the refactoring of the maths is a good idea (I don't think so) but it shouldn't be part of this patch and it shouldn't be described as a fix. David