From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: How to get a sense of VM pressure Date: Sun, 27 Jul 2008 16:43:31 +1000 Message-ID: <200807271643.32338.rusty@rustcorp.com.au> References: <488A1398.7020004@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <488A1398.7020004@goop.org> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: virtualization@lists.linux-foundation.org Cc: Jeremy Fitzhardinge , Linux Kernel Mailing List , Virtualization Mailing List , Rik van Riel , Andrew Morton , Linux Memory Management List List-Id: virtualization@lists.linuxfoundation.org On Saturday 26 July 2008 03:55:36 Jeremy Fitzhardinge wrote: > So I guess what I need is some measurement of "memory use" which is > perhaps akin to a system-wide RSS; a measure of the number of pages > being actively used, that if non-resident would cause a large amount of > paging. If you shrink the domain down to that number of pages + some > padding (x%?), then the system will run happily in a stable state. If > that number increases, then the system will need new memory soon, to > stop it from thrashing. And if that number goes way below the domain's > actual memory allocation, then it has "too much" memory. Like everyone, I've thought about this. The shrinker callbacks seem like a candidate here; have you played with them at all? Some dynamic tension between the shrinker callback and slow feed of pages to the balloon seems like it should work... Rusty.