O syslog é inundado com mensagens PF_RING

Question

Eu tenho ntop rodando em um servidor Debian 9 (Stretch), e ele está inundando /var/log/syslog com as seguintes mensagens a cada 10 segundos :

Sep 21 11:51:18 brutus kernel: [67801.273760] [PF_RING] removing lo/info from /proc [net=18446626341580989120]
Sep 21 11:51:18 brutus kernel: [67801.273762] [PF_RING] removing lo from /proc [net=18446626341580989120]
Sep 21 11:51:18 brutus kernel: [67801.461801] [PF_RING] removing lo/info from /proc [net=18446626341682619200]
Sep 21 11:51:18 brutus kernel: [67801.461804] [PF_RING] removing lo from /proc [net=18446626341682619200]
Sep 21 11:51:18 brutus kernel: [67801.464365] [PF_RING] removing lo/info from /proc [net=18446626341794546432]
Sep 21 11:51:18 brutus kernel: [67801.464367] [PF_RING] removing lo from /proc [net=18446626341794546432]
Sep 21 11:51:18 brutus kernel: [67801.653773] [PF_RING] removing lo/info from /proc [net=18446626341794562944]
Sep 21 11:51:18 brutus kernel: [67801.653776] [PF_RING] removing lo from /proc [net=18446626341794562944]
Sep 21 11:51:28 brutus kernel: [67811.209792] [PF_RING] removing lo/info from /proc [net=18446626341580989376]
Sep 21 11:51:28 brutus kernel: [67811.209795] [PF_RING] removing lo from /proc [net=18446626341580989376]
Sep 21 11:51:28 brutus kernel: [67811.381941] [PF_RING] removing lo/info from /proc [net=18446626343937008704]
Sep 21 11:51:28 brutus kernel: [67811.381944] [PF_RING] removing lo from /proc [net=18446626343937008704]
Sep 21 11:51:28 brutus kernel: [67811.384587] [PF_RING] removing lo/info from /proc [net=18446626341791761408]
Sep 21 11:51:28 brutus kernel: [67811.384589] [PF_RING] removing lo from /proc [net=18446626341791761408]
Sep 21 11:51:28 brutus kernel: [67811.573931] [PF_RING] removing lo/info from /proc [net=18446626341783028864]
Sep 21 11:51:28 brutus kernel: [67811.573934] [PF_RING] removing lo from /proc [net=18446626341783028864]

1. O que essas mensagens significam?
2. Como posso reduzir a quantidade de mensagens de log? É difícil encontrar mais alguma coisa em meio a tudo isso.