# Re: \[PATCH v3\] samples/bpf: Add xdp\_stat sample program

- From: Daniel Borkmann \<daniel@iogearbox.net\>
- Date: 2020-02-17 15:22:18 
- List: netdev
- Page: https://ratatoskr.run/netdev/2020/02/7727156
- Thread: https://ratatoskr.run/bpf/2019/12/7724661/t.md

```text
On 1/29/20 4:54 AM, Eric Sage wrote:
> At Facebook we use tail calls to jump between our firewall filters and
> our L4LB. This is a program I wrote to estimate per program performance
> by swapping out the entries in the program array with interceptors that
> take measurements and then jump to the original entries.
>
> I found the sample programs to be invaluable in understanding how to use
> the libbpf API (as well as the test env from the xdp-tutorial repo for
> testing), and want to return the favor. I am currently working on
> my next iteration that uses fentry/fexit to be less invasive,
> but I thought it was an interesting PoC of what you can do with program
> arrays.
>
> Signed-off-by: Eric Sage <redacted>

Now that bpf-next is back open, this needs a rebase for proceeding to get merged.

Thanks,
Daniel
```