thousands of kworker processes with 4.7.x and 4.8-rc*

[Tomasz Chmielewski]

On several servers running 4.7.x and 4.8-rc6/7 kernels I'm seeing 
thousands of kworker processes.

# ps auxf|grep -c kworker
2104


Load average goes into hundreds on a pretty much idle server (biggest 
CPU and RAM consumers are probably SSHD with one user logged in and 
rsyslog writing ~1 line per minute):

# uptime
 06:58:56 up 26 min,  1 user,  load average: 146.11, 215.46, 105.70


# uptime
 06:59:48 up 26 min,  1 user,  load average: 305.20, 240.84, 120.25


Sometimes seeing lots of them in "D" state:

root     19474  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:208]
root     19475  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:209]
root     19477  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:211]
root     19480  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:214]
root     19483  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:217]
root     19485  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:219]
root     19486  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:220]
root     19487  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:221]
root     19492  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/0:226]
root     19533  0.0  0.0      0     0 ?        D    06:54   0:00  \_ 
[kworker/4:257]


Is it a known issue?

The server has 8 CPUs and 32 GB RAM.


Tomasz Chmielewski
https://lxadm.com