On 16/03/2016 11:49, Christian Borntraeger wrote: > Seems to lockup.
That's an improvement actually. :) > Thread 3 (Thread 0x3ff888dc910 (LWP 88958)): > #0 0x000003ff8ca90cd4 in __lll_lock_wait () at /lib64/libpthread.so.0 > #1 0x000003ff8ca93e74 in __lll_lock_elision () at /lib64/libpthread.so.0 Off-topic, I love how s390 backtraces always have a little bit of showing off in them! :) > #3 0x00000000800b713e in virtio_blk_data_plane_start (s=0xba232d80) at > /home/cborntra/REPOS/qemu/hw/block/dataplane/virtio-blk.c:224 > #4 0x00000000800b4ea0 in virtio_blk_handle_output (vdev=0xb9eee7e8, > vq=0xba305270) at /home/cborntra/REPOS/qemu/hw/block/virtio-blk.c:590 > #5 0x00000000800ef3dc in virtio_queue_notify_vq (vq=0xba305270) at > /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1095 > #6 0x00000000800f1c9c in virtio_queue_host_notifier_read (n=0xba3052c8) at > /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1785 > #7 0x00000000800f1e14 in virtio_queue_set_host_notifier_fd_handler > (vq=0xba305270, assign=false, set_handler=false) at > /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1817 > #8 0x0000000080109c50 in virtio_ccw_set_guest2host_notifier (dev=0xb9eed6a0, > n=0, assign=false, set_handler=false) at > /home/cborntra/REPOS/qemu/hw/s390x/virtio-ccw.c:97 > #9 0x0000000080109ef2 in virtio_ccw_stop_ioeventfd (dev=0xb9eed6a0) at > /home/cborntra/REPOS/qemu/hw/s390x/virtio-ccw.c:154 One bug is here: virtio_ccw_stop_ioeventfd, in this case, should pass assign=true to virtio_ccw_set_guest2host_notifier. (Assuming my understanding of assign=true is correct; I think it means "I'm going to set up another host notifier handler"). In dataplane, instead, all calls to virtio_queue_set_host_notifier_fd_handler and virtio_queue_aio_set_host_notifier_handler should have assign=true. The ioeventfd is just being moved from one aiocontext to another. Paolo > #10 0x000000008010d5aa in virtio_ccw_set_host_notifier (d=0xb9eed6a0, n=0, > assign=true) at /home/cborntra/REPOS/qemu/hw/s390x/virtio-ccw.c:1211 > #11 0x00000000800b722c in virtio_blk_data_plane_start (s=0xba232d80) at > /home/cborntra/REPOS/qemu/hw/block/dataplane/virtio-blk.c:242 > #12 0x00000000800b4ea0 in virtio_blk_handle_output (vdev=0xb9eee7e8, > vq=0xba305270) at /home/cborntra/REPOS/qemu/hw/block/virtio-blk.c:590 > #13 0x00000000800ef3dc in virtio_queue_notify_vq (vq=0xba305270) at > /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1095 > #14 0x00000000800f1c9c in virtio_queue_host_notifier_read (n=0xba3052c8) at > /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1785 > #15 0x00000000802f1cd4 in aio_dispatch (ctx=0xb9e81c70) at > /home/cborntra/REPOS/qemu/aio-posix.c:327 > #16 0x00000000802df31c in aio_ctx_dispatch (source=0xb9e81c70, callback=0x0, > user_data=0x0) at /home/cborntra/REPOS/qemu/async.c:232
