From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael R. Hines" Subject: Re: [PATCHv2] rdma: add a new IB_ACCESS_GIFT flag Date: Tue, 09 Apr 2013 13:56:00 -0400 Message-ID: <51645630.3030608@linux.vnet.ibm.com> References: <20130324155153.GA8597@redhat.com> <515F3160.4020007@linux.vnet.ibm.com> <515F3A0F.5030507@linux.vnet.ibm.com> <20130409163929.GA7661@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130409163929.GA7661-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Michael S. Tsirkin" Cc: Roland Dreier , qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org, "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Yishai Hadas , LKML , Hal Rosenstock , Jason Gunthorpe , Sean Hefty , Christoph Lameter List-Id: linux-rdma@vger.kernel.org On 04/09/2013 12:39 PM, Michael S. Tsirkin wrote: > On Fri, Apr 05, 2013 at 04:54:39PM -0400, Michael R. Hines wrote: >> To be more specific, here's what I did: >> >> 1. apply kernel module patch - re-insert module >> 1. QEMU does: ibv_reg_mr(........IBV_ACCESS_GIFT | IBV_ACCESS_REMOTE_READ) >> 2. Start the RDMA migration >> 3. Migration completes without any errors >> >> This test does *not* work with a cgroup swap limit, however. The >> process gets killed. (Both with and without GIFT) >> >> - Michael > Try to attach a debugger and see where it is when it gets killed? > It's killed by cgroups - not a CPU exception. The same test works fine using TCP migration with cgroups - everything is fine there. The memory that RDMA attempted to register hits some kind of cgroups policy which results in a kernel message saying that the cgroup swap limit was hit and then it goes ahead and kills the process altogether. It's not a QEMU problem - it seems to be a kernel bug. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html