Висит вот так:
# strace -fF -p 15449
strace: deprecated option -F ignored
strace: Process 15449 attached with 20 threads
[pid 15621] futex(0x55d4fe8fcf18, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid 15619] restart_syscall(<... resuming interrupted read ...> <unfinished ...>
[pid 15616] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15615] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15613] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15612] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15610] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15609] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15607] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15606] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15604] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15603] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15602] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15601] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15600] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15599] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15598] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15596] futex(0x55d4fcf92860, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...>
[pid 15450] futex(0x55d4fcf98108, FUTEX_WAIT, 4294967295, NULL <unfinished ...>
[pid 15449] ppoll([{fd=120, events=POLLIN|POLLERR|POLLHUP}, {fd=118, events=POLLIN|POLLERR|POLLHUP}, {fd=19, events=POLLIN|POLLERR|POLLHUP}, {fd=12, events=POLLIN|POLLERR|POLLHUP}], 4, NULL, NULL, 8

fd=120 - это какой-то eventfd

До обновления на p9 таких проблем не было.

VM ни на что не реагирует, только kill -9