console getty uses 1.5% of CPU

Poul-Henning Kamp phk at
Wed Apr 7 05:22:50 UTC 2021

I have two 12.2-R systems where the serial console is attached to a terminal server.

When there are no TCP connections to the terminal server, getty soaks up 1.5% of the
CPU in the kernel (sleeping in "ttyin"), ktrace shows no system calls.

When a TCP connection is made to the terminal server, which raises the modem-handshake
on the DE-9 connector, the CPU usage stops.

Anybody else seeing something like this ?

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

More information about the freebsd-current mailing list