From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rik van Riel Subject: Re: [patch 1/9] Guest page hinting: unused / free pages. Date: Tue, 12 Sep 2006 18:47:29 -0400 Message-ID: <45073901.8020906@redhat.com> References: <20060901110908.GB15684@skybase> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20060901110908.GB15684@skybase> Sender: linux-kernel-owner@vger.kernel.org To: Martin Schwidefsky Cc: linux-kernel@vger.kernel.org, virtualization@lists.osdl.org, akpm@osdl.org, nickpiggin@yahoo.com.au, frankeh@watson.ibm.com, rhim@cc.gateh.edu List-Id: virtualization@lists.linuxfoundation.org Martin Schwidefsky wrote: > From: Martin Schwidefsky > From: Hubertus Franke > From: Himanshu Raj > > [patch 1/9] Guest page hinting: unused / free pages. > > A very simple but already quite effective improvement in the handling > of guest memory vs. host memory is to tell the host when pages are > free. Would it be an idea to place this interface in-between the per-cpu free page lists and the buddy allocator, so we can move a batch of pages around at once and do the hinting in a batched fashion ? That way the overhead will be acceptable not just on S390 (where things are millicoded), but also on hypervisor based virtualization like Xen. Easy enough to pass a vector of pages to the hypervisor. -- What is important? What you want to be true, or what is true?