From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Subject: Re: [PATCH 0/3] KVM: PPC: Book3S HV: More flexible allocator for linear memory Date: Fri, 14 Sep 2012 22:45:04 +1000 Message-ID: <20120914124504.GF15028@bloggs.ozlabs.ibm.com> References: <20120912003427.GH32642@bloggs.ozlabs.ibm.com> <9650229C-2512-4684-98EC-6E252E47C4A9@suse.de> <20120914081140.GC15028@bloggs.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm-ppc@vger.kernel.org, KVM list , linux-mm@kvack.org, m.nazarewicz@samsung.com To: Alexander Graf Return-path: Received: from ozlabs.org ([203.10.76.45]:38953 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751231Ab2INMol (ORCPT ); Fri, 14 Sep 2012 08:44:41 -0400 Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Sep 14, 2012 at 02:13:37PM +0200, Alexander Graf wrote: > So do you think it makes more sense to reimplement a large page allocator in KVM, as this patch set does, or improve CMA to get us really big chunks of linear memory? > > Let's ask the Linux mm guys too :). Maybe they have an idea. I asked the authors of CMA, and apparently it's not limited to MAX_ORDER as I feared. It has the advantage that the memory can be used for other things such as page cache when it's not needed, but not for immovable allocations such as kmalloc. I'm going to try it out. It will need a patch to increase the maximum alignment it allows. Paul.