Regression between r254984 and r255943 on Raspberry Pi: failed to create new mbuf

[Ralf Wenk]

Hello,

while rsync(1)-ing an 1 GB file the rpi gets almost unresponsible
after a while and on the serial console there are lots of

smsc0: warning: failed to create new mbuf

kernel messages. Occasionaly dotted with the

[zone: mbuf_cluster] kern.ipc.nmbclusters limit reached

kernel message. The problem is reproduceable.
Increasing the value of kern.ipc.nmbclusters by the factor of 2 just delayed
the moment the problem happens.

An old r254984 kernel does not show this problem.

r257114 and r255943 do. A test with r255463 is currently ongoing.

Ralf