On Fri, 07 Jul 2017 10:37:59 -0700 John Fastabend <john.fastab...@gmail.com> wrote:
> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c > index 36dc13de..656e334 100644 > --- a/kernel/bpf/devmap.c > +++ b/kernel/bpf/devmap.c [...] > > +void __dev_map_insert_ctx(struct bpf_map *map, u32 key) > +{ > + struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); > + unsigned long *bitmap = this_cpu_ptr(dtab->flush_needed); > + > + set_bit(key, bitmap); > +} I don't like that this adds an atomic op (set_bit) per packet on a fast-path. It shows up on a perf top #6 with xdp_redirect_map. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer