Re: [PATCH v3 bpf-next 10/10] selftests/bpf: cgroup local storage-based network counters

From: Alexei Starovoitov
Date: Fri Sep 28 2018 - 06:40:32 EST


On Fri, Sep 28, 2018 at 11:37:26AM +0100, Roman Gushchin wrote:
> > > > > +
> > > > > + /* Let's check that bytes counter value is reasonable */
> > > > > + if (netcnt.bytes < packets * 500 || netcnt.bytes > packets * 1500) {
> > > >
> > > > since packet count is accurate why byte count would vary ?
> > >
> > > Tbh I'm not sure if the size of the packet here can vary depending
> > > on the environment. Is there a nice way to get the expected size?
> >
> > ping packets should be fixed size depending on v4 vs v6.
> > If 'ping -6' is used, it will force ipv6.
> >
>
> Are we ok to screw up kselftests on v4-only machines?

we already did. Some of the selftests/bpf use ping -6 already.