From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:58324) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UI0fW-0006vd-Em for qemu-devel@nongnu.org; Tue, 19 Mar 2013 13:49:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UI0fT-0000P8-GT for qemu-devel@nongnu.org; Tue, 19 Mar 2013 13:49:50 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:36299) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UI0fT-0000P4-D2 for qemu-devel@nongnu.org; Tue, 19 Mar 2013 13:49:47 -0400 Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 19 Mar 2013 13:49:47 -0400 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 3DEA438C8065 for ; Tue, 19 Mar 2013 13:49:42 -0400 (EDT) Received: from d03av06.boulder.ibm.com (d03av06.boulder.ibm.com [9.17.195.245]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r2JHnfKO337190 for ; Tue, 19 Mar 2013 13:49:41 -0400 Received: from d03av06.boulder.ibm.com (loopback [127.0.0.1]) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r2JHqF8X027411 for ; Tue, 19 Mar 2013 11:52:15 -0600 Message-ID: <5148A52E.6020208@linux.vnet.ibm.com> Date: Tue, 19 Mar 2013 13:49:34 -0400 From: "Michael R. Hines" MIME-Version: 1.0 References: <1363576743-6146-1-git-send-email-mrhines@linux.vnet.ibm.com> <1363576743-6146-4-git-send-email-mrhines@linux.vnet.ibm.com> <20130318104013.GE5267@redhat.com> <5147780C.1080800@linux.vnet.ibm.com> <20130318212646.GB20406@redhat.com> <5147A209.80202@linux.vnet.ibm.com> <20130319081939.GC11259@redhat.com> <51487F68.2060305@linux.vnet.ibm.com> <20130319151606.GA13649@redhat.com> <51488521.4010909@linux.vnet.ibm.com> <20130319153658.GA14317@redhat.com> <51489BC3.3030504@linux.vnet.ibm.com> <51489D05.2000400@redhat.com> In-Reply-To: <51489D05.2000400@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH RDMA support v4: 03/10] more verbose documentation of the RDMA transport List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: aliguori@us.ibm.com, "Michael S. Tsirkin" , qemu-devel@nongnu.org, owasserm@redhat.com, abali@us.ibm.com, mrhines@us.ibm.com, gokul@us.ibm.com I also did a test using RDMA + cgroup, and the kernel killed my QEMU :) So, infiniband is not smart enough to know how to avoid pinning a zero page, I guess. - Michael On 03/19/2013 01:14 PM, Paolo Bonzini wrote: > Il 19/03/2013 18:09, Michael R. Hines ha scritto: >> Allowing QEMU to swap due to a cgroup limit during migration is a viable >> overcommit option? >> >> I'm trying to keep an open mind, but that would kill the migration >> time..... > Would it swap? Doesn't the kernel back all zero pages with a single > copy-on-write page? If that still accounts towards cgroup limits, it > would be a bug. > > Old kernels do not have a shared zero hugepage, and that includes some > distro kernels. Perhaps that's the problem. > > Paolo >