From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx112.postini.com [74.125.245.112]) by kanga.kvack.org (Postfix) with SMTP id 57A0E6B0044 for ; Thu, 8 Nov 2012 17:09:53 -0500 (EST) Received: from mail96-co9 (localhost [127.0.0.1]) by mail96-co9-R.bigfish.com (Postfix) with ESMTP id 87DF8D0054E for ; Thu, 8 Nov 2012 22:08:39 +0000 (UTC) From: KY Srinivasan Subject: RE: [PATCH 1/2] mm: Export vm_committed_as Date: Thu, 8 Nov 2012 22:08:33 +0000 Message-ID: <426367E2313C2449837CD2DE46E7EAF930E0E0EB@CH1PRD0310MB381.namprd03.prod.outlook.com> 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> <426367E2313C2449837CD2DE46E7EAF930E0D0CC@CH1PRD0310MB381.namprd03.prod.outlook.com> <20121108140529.af7849c8.akpm@linux-foundation.org> In-Reply-To: <20121108140529.af7849c8.akpm@linux-foundation.org> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: David Rientjes , 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 > -----Original Message----- > From: Andrew Morton [mailto:akpm@linux-foundation.org] > Sent: Thursday, November 08, 2012 5:05 PM > To: KY Srinivasan > Cc: David Rientjes; Greg KH; olaf@aepfle.de; linux-kernel@vger.kernel.org= ; > andi@firstfloor.org; apw@canonical.com; devel@linuxdriverproject.org; lin= ux- > mm@kvack.org; Hiroyuki Kamezawa; Michal Hocko; Johannes Weiner; Ying Han > Subject: Re: [PATCH 1/2] mm: Export vm_committed_as >=20 > On Thu, 8 Nov 2012 22:01:33 +0000 > KY Srinivasan wrote: >=20 > > > > > > > -----Original Message----- > > > From: David Rientjes [mailto:rientjes@google.com] > > > Sent: Monday, November 05, 2012 5:33 PM > > > 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 > > > > > > On Mon, 5 Nov 2012, KY Srinivasan wrote: > > > > > > > The Hyper-V host has a policy engine for managing available physica= l > memory > > > across > > > > competing virtual machines. This policy decision is based on a numb= er 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 commitmen= t > 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 nee= d some > > > measure of memory > > > > commitments made by the Linux guest. This is the reason I want expo= rt > > > vm_committed_as. > > > > > > > > > > I don't think you should export the symbol itself to modules but rath= er 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.) > > > > Yes, this makes sense. I just want to access (read) this metric. Andrew= , if you > are willing to > > take this patch, I could send one. >=20 > Sure. I suppose that's better, although any module which modifies > committed_as would never pass review (rofl). Thanks Andrew; I will send the patch out along with the appropriately modif= ied balloon driver patch. Regards, K. Y >=20 >=20 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org