On 2023-09-09 10:49:09 [+0800], Hou Tao wrote: > Hi, Hi, > > --- a/kernel/bpf/cpumap.c > > +++ b/kernel/bpf/cpumap.c > > @@ -248,12 +248,12 @@ static int cpu_map_bpf_prog_run(struct bpf_cpu_map_entry *rcpu, void **frames, > > > > nframes = cpu_map_bpf_prog_run_xdp(rcpu, frames, xdp_n, stats); > > > > - if (stats->redirect) > > - xdp_do_flush(); > > - > > if (unlikely(!list_empty(list))) > > cpu_map_bpf_prog_run_skb(rcpu, list, stats); > > > > + if (stats->redirect) > > + xdp_do_flush(); > > + > > The purpose of xdp_do_flush() is to flush xdp frames stashed in per-cpu > cpu_map_flush list into xdp_bulk_queue. But for redirected skbs, these > skbs will be directly added into xdp_bulk_queue() in > cpu_map_generic_redirect(), so I think xdp_do_flush() is not needed for > redirected skbs. Now that I checked the down streams of cpu_map_bpf_prog_run_skb() it does not queue anything to the per-CPU lists like I assumed. You are right, it is no needed. Sorry for the confusion. > > rcu_read_unlock_bh(); /* resched point, may call do_softirq() */ > > > > return nframes; > Sebastian
