Re: Accessing userspace created persistent eBPF maps from kernel bpf restricted C

[David Miller <davem@xxxxxxxxxxxxx>]

From: Kiran T <kiran.lkml@xxxxxxxxx>
Date: Thu, 7 Sep 2017 17:46:47 -0700

> If maps can be made persistent from userspace, but the kernel side
> bpf can't quite access it, it doesn't make much sense :(

Pinning is so that an unload of a BPF program doesn't cause it's maps
to go away.

It's designed so that things like statistics can be persistent across
BPF program loads.

So you can load and unload a BPF program multiple times, and you won't
lose the statistic increments done by earlier instances.