Commit e3366884 authored by Cong Wang's avatar Cong Wang Committed by Alexei Starovoitov
Browse files

lwt_bpf: Replace preempt_disable() with migrate_disable() 



migrate_disable() is just a wrapper for preempt_disable() in
non-RT kernel. It is safe to replace it, and RT kernel will
benefit.

Note that it is introduced since Feb 2020.

Suggested-by: default avatarAlexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201205075946.497763-2-xiyou.wangcong@gmail.com
parent d9054a1f

net/core/lwt_bpf.c

+3 −3
Original line number Diff line number Diff line
@@ -39,10 +39,10 @@ static int run_lwt_bpf(struct sk_buff *skb, struct bpf_lwt_prog *lwt, 
{

	int ret;



	/* Preempt disable and BH disable are needed to protect per-cpu

	/* Migration disable and BH disable are needed to protect per-cpu

	 * redirect_info between BPF prog and skb_do_redirect().

	 */

	preempt_disable();

	migrate_disable();

	local_bh_disable();

	bpf_compute_data_pointers(skb);

	ret = bpf_prog_run_save_cb(lwt->prog, skb);
@@ -78,7 +78,7 @@ static int run_lwt_bpf(struct sk_buff *skb, struct bpf_lwt_prog *lwt, 
	}



	local_bh_enable();

	preempt_enable();

	migrate_enable();



	return ret;

}