Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964797Ab2KEWdU (ORCPT ); Mon, 5 Nov 2012 17:33:20 -0500 Received: from mail-da0-f46.google.com ([209.85.210.46]:40004 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933410Ab2KEWdP (ORCPT ); Mon, 5 Nov 2012 17:33:15 -0500 Date: Mon, 5 Nov 2012 14:33:12 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: KY Srinivasan cc: Andrew Morton , Greg KH , "olaf@aepfle.de" , "linux-kernel@vger.kernel.org" , "andi@firstfloor.org" , "apw@canonical.com" , "devel@linuxdriverproject.org" , "linux-mm@kvack.org" , Hiroyuki Kamezawa , Michal Hocko , Johannes Weiner , Ying Han Subject: RE: [PATCH 1/2] mm: Export vm_committed_as In-Reply-To: <426367E2313C2449837CD2DE46E7EAF930DFA7B8@SN2PRD0310MB382.namprd03.prod.outlook.com> Message-ID: References: <1349654347-18337-1-git-send-email-kys@microsoft.com> <1349654386-18378-1-git-send-email-kys@microsoft.com> <20121008004358.GA12342@kroah.com> <426367E2313C2449837CD2DE46E7EAF930A1FB31@SN2PRD0310MB382.namprd03.prod.outlook.com> <20121008133539.GA15490@kroah.com> <20121009124755.ce1087b4.akpm@linux-foundation.org> <426367E2313C2449837CD2DE46E7EAF930DF7FBB@SN2PRD0310MB382.namprd03.prod.outlook.com> <20121105134456.f655b85a.akpm@linux-foundation.org> <426367E2313C2449837CD2DE46E7EAF930DFA7B8@SN2PRD0310MB382.namprd03.prod.outlook.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: 1284 Lines: 23 On Mon, 5 Nov 2012, KY Srinivasan wrote: > The Hyper-V host has a policy engine for managing available physical memory across > competing virtual machines. This policy decision is based on a number of parameters > including the memory pressure reported by the guest. Currently, the pressure calculation is > based on the memory commitment made by the guest. From what I can tell, the ratio of > currently allocated physical memory to the current memory commitment made by the guest > (vm_committed_as) is used as one of the parameters in making the memory balancing decision on > the host. This is what Windows guests report to the host. So, I need some measure of memory > commitments made by the Linux guest. This is the reason I want export vm_committed_as. > I don't think you should export the symbol itself to modules but rather a helper function that returns s64 that just wraps percpu_counter_read_positive() which your driver could use instead. (And why percpu_counter_read_positive() returns a signed type is a mystery.) -- 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/