From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jes Sorensen Subject: Re: [PATCH 0/3][RFC] NUMA: add host side pinning Date: Fri, 25 Jun 2010 13:00:37 +0200 Message-ID: <4C248C55.9020204@redhat.com> References: <1277327377-29629-1-git-send-email-andre.przywara@amd.com> <4C2288DD.3020207@codemonkey.ws> <865764AB-4E51-4ED4-8832-AED6A237A9D3@suse.de> <4C233A6D.7030805@amd.com> <4C233DAB.60106@redhat.com> <4C2342D1.4090103@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Alexander Graf , Anthony Liguori , "kvm@vger.kernel.org" To: Andre Przywara Return-path: Received: from mx1.redhat.com ([209.132.183.28]:53197 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752557Ab0FYLAs (ORCPT ); Fri, 25 Jun 2010 07:00:48 -0400 In-Reply-To: <4C2342D1.4090103@amd.com> Sender: kvm-owner@vger.kernel.org List-ID: On 06/24/10 13:34, Andre Przywara wrote: > Avi Kivity wrote: >> On 06/24/2010 01:58 PM, Andre Przywara wrote: >> Non-anonymous memory doesn't work well with ksm and transparent >> hugepages. Is it possible to use anonymous memory rather than file >> backed? > I'd prefer non-file backed, too. But that is how the current huge pages > implementation is done. We could use MAP_HUGETLB and declare NUMA _and_ > huge pages as 2.6.32+ only. Unfortunately I didn't find an easy way to > detect the presence of the MAP_HUGETLB flag. If the kernel does not > support it, it seems that mmap silently ignores it and uses 4KB pages > instead. Bit behind on the mailing list, but I think this look very promising. I really think it makes more sense to make QEMU aware of the NUMA setup as well, rather than relying on numctl to do the work outside. One thing you need to consider is what happens with migration once a user specifies -numa. IMHO it is acceptable to simply disable migration for the given guest. Cheers, Jes PS: Are you planning on submitting anything to Linux Plumbers Conference about this? :)