From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bharata B Rao Subject: Re: [Qemu-devel] [PATCH 19/23] userfaultfd: activate syscall Date: Tue, 8 Sep 2015 19:07:15 +0530 Message-ID: <20150908133647.GA17433@in.ibm.com> References: <1431624680-20153-1-git-send-email-aarcange@redhat.com> <1431624680-20153-20-git-send-email-aarcange@redhat.com> <20150811100728.GB4587@in.ibm.com> <20150811134826.GI4520@redhat.com> <20150812052346.GC4587@in.ibm.com> <1441692486.14597.17.camel@ellerman.id.au> <20150908063948.GB678@in.ibm.com> <20150908085946.GC2246@work-vm> <20150908095915.GC678@in.ibm.com> <20150908124652.GK2246@work-vm> Reply-To: bharata@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150908124652.GK2246@work-vm> Sender: owner-linux-mm@kvack.org To: "Dr. David Alan Gilbert" Cc: Michael Ellerman , Andrea Arcangeli , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-api@vger.kernel.org, zhang.zhanghailiang@huawei.com, Pavel Emelyanov , Johannes Weiner , Hugh Dickins , Sanidhya Kashyap , Dave Hansen , Andres Lagar-Cavilla , Mel Gorman , Paolo Bonzini , "Kirill A. Shutemov" , "Huangpeng (Peter)" , Andy Lutomirski , Linus Torvalds Peter Feiner

List-Id: linux-api@vger.kernel.org On Tue, Sep 08, 2015 at 01:46:52PM +0100, Dr. David Alan Gilbert wrote: > * Bharata B Rao (bharata@linux.vnet.ibm.com) wrote: > > On Tue, Sep 08, 2015 at 09:59:47AM +0100, Dr. David Alan Gilbert wrote: > > > * Bharata B Rao (bharata@linux.vnet.ibm.com) wrote: > > > > In fact I had successfully done postcopy migration of sPAPR guest with > > > > this setup. > > > > > > Interesting - I'd not got that far myself on power; I was hitting a problem > > > loading htab ( htab_load() bad index 2113929216 (14848+0 entries) in htab stream (htab_shift=25) ) > > > > > > Did you have to make any changes to the qemu code to get that happy? > > > > I should have mentioned that I tried only QEMU driven migration within > > the same host using wp3-postcopy branch of your tree. I don't see the > > above issue. > > > > (qemu) info migrate > > capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off compress: off x-postcopy-ram: on > > Migration status: completed > > total time: 39432 milliseconds > > downtime: 162 milliseconds > > setup: 14 milliseconds > > transferred ram: 1297209 kbytes > > throughput: 270.72 mbps > > remaining ram: 0 kbytes > > total ram: 4194560 kbytes > > duplicate: 734015 pages > > skipped: 0 pages > > normal: 318469 pages > > normal bytes: 1273876 kbytes > > dirty sync count: 4 > > > > I will try migration between different hosts soon and check. > > I hit that on the same host; are you sure you've switched into postcopy mode; > i.e. issued a migrate_start_postcopy before the end of migration? Sorry I was following your discussion with Li in this thread https://www.marc.info/?l=qemu-devel&m=143035620026744&w=4 and it wasn't obvious to me that anything apart from turning on the x-postcopy-ram capability was required :( So I do see the problem now. At the source ------------- Error reading data from KVM HTAB fd: Bad file descriptor Segmentation fault At the target ------------- htab_load() bad index 2113929216 (14336+0 entries) in htab stream (htab_shift=25) qemu-system-ppc64: error while loading state section id 56(spapr/htab) qemu-system-ppc64: postcopy_ram_listen_thread: loadvm failed: -22 qemu-system-ppc64: VQ 0 size 0x100 Guest index 0x0 inconsistent with Host index 0x1f: delta 0xffe1 qemu-system-ppc64: error while loading state for instance 0x0 of device 'pci@800000020000000:00.0/virtio-net' *** Error in `./ppc64-softmmu/qemu-system-ppc64': corrupted double-linked list: 0x00000100241234a0 *** ======= Backtrace: ========= /lib64/power8/libc.so.6Segmentation fault -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org