Server shutdown in progress for hours

I have a relatively large database (> 500 GB), and have run a yum update last night, that upgraded mysql-community-server.

Since then, the MySQL server has been in "Server shutdown in progress" status for 16 hours now:

# service mysqld status
Redirecting to /bin/systemctl status mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/mysqld.service.d
           └─override.conf
   Active: deactivating (stop-sigterm) since Mon 2020-07-20 01:18:28 CEST; 14h ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
 Main PID: 8318 (mysqld)
   Status: "Server shutdown in progress"
   CGroup: /system.slice/mysqld.service
           └─8318 /usr/sbin/mysqld

Plus, mysqld is now constantly using 300% CPU.

Is there a problem, or is this just a consequence of the database being large? Is there any way I can get some idea of the time left, or see what the server is actually doing?

And is there anything I can do to speed up the process?

For information, the server is a 6-core Xeon with 128GB RAM and NVMe drives, so rather fast.

There is plenty of available disk space and free RAM.

# free -m
              total        used        free      shared  buff/cache   available
Mem:         128889       88292       11189        2225       29407       37145
Swap:         16381        5168       11213

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Update: it’s now been 72 hours. Nothing has changed.