Messages in this thread | | | Subject | Re: Hang in 9p/virtio | From | Vegard Nossum <> | Date | Tue, 2 Aug 2016 15:35:34 +0200 |
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On 08/02/2016 11:13 AM, Vegard Nossum wrote: > On 08/02/2016 11:03 AM, Cornelia Huck wrote: >> On Sat, 30 Jul 2016 23:42:18 +0200 >> Vegard Nossum <vegard.nossum@oracle.com> wrote: >> >>> Hi, >>> >>> With fault injection triggering an allocation failure for the >>> alloc_indirect() call in virtqueue_add() I'm seeing a hang in >>> p9_virtio_zc_request() -- it seems to be waiting here indefinitely >>> (i.e. at least 120 seconds): >>> > [...] > >> What happens is that the code falls back to direct virtio addressing >> (after indirect addressing failed) - and this should work. >> >> I'm more inclined to suspect a qemu instead of a kernel bug, as your >> qemu version is quite old and there have been fixes in the virtio >> buffer handling and virtio-9p in the meantime. (I'm suspecting >> "virtio-9p: fix any_layout".) >> >> Could you retry with a more recent qemu (at least version 2.4)? > > I think maybe the version number in the stack trace is a bit misleading, > this is the full/actual version: > > $ kvm --version > QEMU emulator version 2.5.0 (Debian 1:2.5+dfsg-5ubuntu10.1), Copyright > (c) 2003-2008 Fabrice Bellard > > I'll still try to get qemu from git and see if it makes a difference. > Thanks,
I still seem to get it:
$ qemu-system-x86_64 --version QEMU emulator version 2.6.91 (v2.7.0-rc1-2-gcc0100f-dirty), Copyright (c) 2003-2008 Fabrice Bellard
INFO: task trinity-c2:26510 blocked for more than 120 seconds. Not tainted 4.7.0+ #71 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. trinity-c2 D ffff88010509fcf0 26600 26510 1238 0x10080004 ffff88010509fcf0 ffff880119ea1080 ffff880119ea1098 ffff88011ada06a0 ffff88011ada06c8 ffff88011ad9fd58 ffffffff844d3060 ffff880119d0db00 ffff880119ea0000 ffff880105098000 ffffed0020a13001 ffff880105098008 Call Trace: [<ffffffff838a01fa>] schedule+0x9a/0x1c0 [<ffffffff838a0373>] schedule_preempt_disabled+0x13/0x20 [<ffffffff838a4046>] mutex_lock_nested+0x2d6/0x7d0 [<ffffffff81512244>] ? __fdget_pos+0x84/0xb0 [<ffffffff838a3d70>] ? ww_mutex_unlock+0x260/0x260 [<ffffffff814bb510>] ? do_pwritev+0x170/0x170 [<ffffffff81512244>] __fdget_pos+0x84/0xb0 [<ffffffff814bad19>] do_readv+0x79/0x270 [<ffffffff814baca0>] ? vfs_readv+0xa0/0xa0 [<ffffffff81dd1fd3>] ? __this_cpu_preempt_check+0x13/0x20 [<ffffffff814bb510>] ? do_pwritev+0x170/0x170 [<ffffffff814bb51b>] SyS_readv+0xb/0x10 [<ffffffff81005391>] do_syscall_64+0x1a1/0x460 [<ffffffff8137335a>] ? __context_tracking_enter+0xaa/0x200 [<ffffffff838adc6a>] entry_SYSCALL64_slow_path+0x25/0x25 1 lock held by trinity-c2/26510: #0: (&f->f_pos_lock){......}, at: [<ffffffff81512244>] __fdget_pos+0x84/0xb0
Showing all locks held in the system: 2 locks held by khungtaskd/505: #0: (rcu_read_lock){......}, at: [<ffffffff812baf3f>] watchdog+0xff/0x840 #1: (tasklist_lock){......}, at: [<ffffffff811e1f80>] debug_show_all_locks+0x70/0x280 1 lock held by trinity-c1/26123: #0: (&f->f_pos_lock){......}, at: [<ffffffff81512244>] __fdget_pos+0x84/0xb0 1 lock held by trinity-c2/26510: #0: (&f->f_pos_lock){......}, at: [<ffffffff81512244>] __fdget_pos+0x84/0xb0 1 lock held by trinity-c0/29159: #0: (&f->f_pos_lock){......}, at: [<ffffffff81512244>] __fdget_pos+0x84/0xb0
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Kernel panic - not syncing: hung_task: blocked tasks CPU: 0 PID: 505 Comm: khungtaskd Not tainted 4.7.0+ #71 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
Vegard
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