From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hill Subject: Re: Shutting down a VM with Kernel 4.14 will sometime hang and a reboot is the only way to recover. Date: Fri, 24 Nov 2017 11:19:10 -0500 Message-ID: <6a6aed7c-0707-2e37-5767-826973dad534@redhat.com> References: <92c4f997-80db-fabf-98c8-fcb92da064a7@redhat.com> <7bd45f84-d07e-7fca-6ca3-07dededd092d@redhat.com> <29f8e09f-8920-52d0-02f4-c0fb779135ee@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit To: Jason Wang , Paolo Bonzini , kvm@vger.kernel.org Return-path: Received: from mail-qk0-f194.google.com ([209.85.220.194]:39939 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753495AbdKXQTO (ORCPT ); Fri, 24 Nov 2017 11:19:14 -0500 Received: by mail-qk0-f194.google.com with SMTP id c123so14720077qkf.7 for ; Fri, 24 Nov 2017 08:19:14 -0800 (PST) In-Reply-To: Content-Language: en-US Sender: kvm-owner@vger.kernel.org List-ID: It's really hard to reproduce actually because in order to hit this issue, I must do the following: 1) Create an undercloud VM (tripleo openstack) 2) Update it, install an undercloud 3) Create 7 other VMs 4) Deploy an overcloud on these 7 VMs 5) Stop those VMs 6) Try stopping the undercloud VM and it get stucks "in shutdown" It breaks here ... I tried reproducing this by starting/stopping VMs and I wasn't able to hit it ...   It takes a good 2-3 hours each time I test this. I get this issue only with 4.14 and later and I wasn't able to reproduce this with 4.13 and older. On 2017-11-23 10:11 PM, Jason Wang wrote: > > > On 2017年11月24日 07:48, Paolo Bonzini wrote: >> Jason, any ideas? >> >> Thanks, >> >> Paolo >> >> On 22/11/2017 19:22, David Hill wrote: >>> ore than 120 seconds. >>>      [ 7496.552987]       Tainted: G          I >>>      4.14.0-0.rc1.git3.1.fc28.x86_64 #1 >>>      [ 7496.552996] "echo 0 /proc/sys/kernel/hung_task_timeout_secs" >>>      disables this message. >>>      [ 7496.553006] qemu-system-x86 D12240  5978      1 0x00000004 >>>      [ 7496.553024] Call Trace: >>>      [ 7496.553044]  __schedule+0x2dc/0xbb0 >>>      [ 7496.553055]  ? trace_hardirqs_on+0xd/0x10 >>>      [ 7496.553074]  schedule+0x3d/0x90 >>>      [ 7496.553087]  vhost_net_ubuf_put_and_wait+0x73/0xa0 [vhost_net] >>>      [ 7496.553100]  ? finish_wait+0x90/0x90 >>>      [ 7496.553115]  vhost_net_ioctl+0x542/0x910 [vhost_net] >>>      [ 7496.553144]  do_vfs_ioctl+0xa6/0x6c0 >>>      [ 7496.553166]  SyS_ioctl+0x79/0x90 >>>      [ 7496.553182]  entry_SYSCALL_64_fastpath+0x1f/0xbe >>>      [ 7496.553190] RIP: 0033:0x7fa1ea0e1817 >>>      [ 7496.553196] RSP: 002b:00007ffe3d854bc8 EFLAGS: 00000246 >>>      ORIG_RAX: 0000000000000010 >>>      [ 7496.553209] RAX: ffffffffffffffda RBX: 000000000000001d RCX: >>>      00007fa1ea0e1817 >>>      [ 7496.553215] RDX: 00007ffe3d854bd0 RSI: 000000004008af30 RDI: >>>      0000000000000021 >>>      [ 7496.553222] RBP: 000055e33352b610 R08: 000055e33024a6f0 R09: >>>      000055e330245d92 >>>      [ 7496.553228] R10: 000055e33344e7f0 R11: 0000000000000246 R12: >>>      000055e33351a000 >>>      [ 7496.553235] R13: 0000000000000001 R14: 0000000400000000 R15: >>>      0000000000000000 >>>      [ 7496.553284] >>>                     Showing all locks held in the system: >>>      [ 7496.553313] 1 lock held by khungtaskd/161: >>>      [ 7496.553319]  #0:  (tasklist_lock){.+.+}, at: >>>      [] debug_show_all_locks+0x3d/0x1a0 >>>      [ 7496.553373] 1 lock held by in:imklog/1194: >>>      [ 7496.553379]  #0:  (&f->f_pos_lock){+.+.}, at: >>>      [] __fdget_pos+0x4c/0x60 >>>      [ 7496.553541] 1 lock held by qemu-system-x86/5978: >>>      [ 7496.553547]  #0:  (&dev->mutex#3){+.+.}, at: >>>      [] vhost_net_ioctl+0x358/0x910 [vhost_net] > > Hi: > > The backtrace shows zero copied skb was not sent for a long while for > some reason. This could be either a bug in vhost_net or somewhere in > the host driver, qdiscs or others. > > What's your network setups in host (e.g the qdiscs or network driver)? > Can you still hit the issue if you switch to use another type of > ethernet driver/cards? Can this still be reproducible in net.git > (https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/). > > Will try to reproduce this locally. > > Thanks