Backends stunk in wait event IPC/MessageQueueInternal

Hi, hackers

I had an incident on my Postgres 14 that queries hung in wait event
IPC / MessageQueueInternal, MessageQueueReceive. It likes [1],
however, it doesn't have any discussions.

The process cannot be terminated by pg_terminate_backend(), although
it returns true.

Here is the call stack comes from pstack:

485073: /opt/local/pgsql/14/bin/postgres
fffffb7fef216f4a ioctl (d, d001, fffffb7fffdfa0e0)
00000000008b8ec2 WaitEventSetWait () + 112
00000000008b920f WaitLatch () + 6f
00000000008bf434 shm_mq_wait_internal () + 64
00000000008bff74 shm_mq_receive () + 2b4
000000000079fdc8 TupleQueueReaderNext () + 28
000000000077d8ca gather_merge_readnext () + 13a
000000000077db25 ExecGatherMerge () + 215
0000000000790675 ExecNextLoop () + 175
0000000000790675 ExecNextLoop () + 175
000000000076267d standard_ExecutorRun () + fd
fffffb7fe3965fbd pgss_executorRun () + fd
00000000008df99b PortalRunSelect () + 1cb
00000000008e0dcf PortalRun () + 17f
00000000008ddacd PostgresMain () + 100d
0000000000857f62 ServerLoop () + cd2
0000000000858cee main () + 453
00000000005ab777 _start_crt () + 87
00000000005ab6d8 _start () + 18

Any suggestions? Thanks in advance!

[1] https://www.postgresql.org/message-id/flat/E9FA92C2921F31408041863B74EE4C2001A479E590%40CCPMAILDAG03.cantab.local

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Regrads,
Japin Li.
ChengDu WenWu Information Technology Co.,Ltd.