From mboxrd@z Thu Jan 1 00:00:00 1970 From: Taehee Yoo Subject: [PATCH bpf-next] lwt_bpf: remove unnecessary rcu_read_lock in run_lwt_bpf Date: Mon, 30 Jul 2018 22:22:59 +0900 Message-ID: <20180730132259.6338-1-ap420073@gmail.com> Cc: netdev@vger.kernel.org, ap420073@gmail.com To: daniel@iogearbox.net, ast@kernel.org Return-path: Received: from mail-pg1-f193.google.com ([209.85.215.193]:43506 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726649AbeG3O6I (ORCPT ); Mon, 30 Jul 2018 10:58:08 -0400 Received: by mail-pg1-f193.google.com with SMTP id d17-v6so2826208pgv.10 for ; Mon, 30 Jul 2018 06:23:09 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: run_lwt_bpf is called by bpf_{input/output/xmit}. These functions are already protected by rcu_read_lock. because lwtunnel_{input/output/xmit} holds rcu_read_lock and then calls bpf_{input/output/xmit}. So that rcu_read_lock in the run_lwt_bpf is unnecessary. Signed-off-by: Taehee Yoo --- net/core/lwt_bpf.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c index e7e626f..a49c7ba 100644 --- a/net/core/lwt_bpf.c +++ b/net/core/lwt_bpf.c @@ -50,10 +50,8 @@ static int run_lwt_bpf(struct sk_buff *skb, struct bpf_lwt_prog *lwt, * mixing with BH RCU lock doesn't work. */ preempt_disable(); - rcu_read_lock(); bpf_compute_data_pointers(skb); ret = bpf_prog_run_save_cb(lwt->prog, skb); - rcu_read_unlock(); switch (ret) { case BPF_OK: -- 2.9.3