# Re: bpfilter causes a leftover kernel process

- From: Alexei Starovoitov \<hidden\>
- Date: 2018-10-17 00:30:25 
- List: netdev
- Page: https://ratatoskr.run/netdev/2018/10/11111902
- Thread: https://ratatoskr.run/netdev/2018/08/11106517/t.md

```text
On Wed, Sep 5, 2018 at 5:05 PM Olivier Brunel [ref] wrote:
>
> You'll see in the end that systemd complains that it can't
> unmount /oldroot (EBUSY), aka the root fs; and that's because of the
> bpfilter helper, which wasn't killed because it's seen as a kernel
> thread due to its empty command line and therefore not signaled.

thanks for tracking it down.
can somebody send a patch to give bpfilter non-empty cmdline?
I think that would be a better fix than tweaking all pid1s.
```