From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [Android-virt] [PATCH v5 08/13] ARM: KVM: Handle guest faults in KVM Date: Tue, 13 Dec 2011 16:27:02 +0200 Message-ID: <4EE760B6.8010603@redhat.com> References: <20111211102403.21693.6887.stgit@localhost> <20111211102509.21693.23709.stgit@localhost> <4EE61851.5070308@redhat.com> <4EE71EBF.2080700@redhat.com> <4EE751D9.4070907@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Marc.Zyngier@arm.com, android-virt@lists.cs.columbia.edu, tech@virtualopensystems.com To: Christoffer Dall Return-path: Received: from mx1.redhat.com ([209.132.183.28]:45468 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755355Ab1LMO1P (ORCPT ); Tue, 13 Dec 2011 09:27:15 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 12/13/2011 03:44 PM, Christoffer Dall wrote: > >> > It's not really critical to have efficient reclaim here, since it > >> > happens so rarely. It just needs to do something. > >> > > >> > >> when would you trigger it - when it reaches a certain limit, or? And > >> then what, free the lot and re-allocate what's needed? > > > > The kernel triggers it based on internal pressure. It tells you how > > much pressure to apply, so you just translate it to a number of pages to > > free. > > > > > > ok, so we pick those pages at random? (perhaps trying to avoid hitting > the guest kernel at least for Linux, or...?) x86 has a sort of poorly managed LRU; it's wildly inaccurate but doesn't hurt in practice since it only triggers under severe memory pressure anyway. > > It doesn't have to be there for the merge but I recommend giving it high > > priority. At least read and understand the code so the addition will > > follow naturally. > > > will do - I will make it a Christmas activity. I was hoping to to get the ARM port as a present... -- error compiling committee.c: too many arguments to function