[bpf-next V2 PATCH 2/3] xdp: explicit inline __xdp_map_lookup_elem
From: Jesper Dangaard Brouer <hidden>
Date: 2018-09-03 12:14:02
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Martin KaFai Lau, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The compiler chooses to not-inline the function __xdp_map_lookup_elem, because it can see that it is used by both Generic-XDP and native-XDP do redirect calls (xdp_do_generic_redirect_map and xdp_do_redirect_map). The compiler cannot know that this is a bad choice, as it cannot know that a net device cannot run both XDP modes (Generic or Native) at the same time. Thus, mark this function inline, even-though we normally leave this up-to the compiler. Signed-off-by: Jesper Dangaard Brouer <redacted> --- net/core/filter.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index 520f5e9e0b73..ec1b4eb0d3d4 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -3232,7 +3232,7 @@ void xdp_do_flush_map(void) } EXPORT_SYMBOL_GPL(xdp_do_flush_map); -static void *__xdp_map_lookup_elem(struct bpf_map *map, u32 index) +static inline void *__xdp_map_lookup_elem(struct bpf_map *map, u32 index) { switch (map->map_type) { case BPF_MAP_TYPE_DEVMAP:
@@ -3275,7 +3275,7 @@ static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp, WRITE_ONCE(ri->map, NULL); fwd = __xdp_map_lookup_elem(map, index); - if (!fwd) { + if (unlikely(!fwd)) { err = -EINVAL; goto err; }
@@ -3303,7 +3303,7 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, u32 index = ri->ifindex; int err; - if (map) + if (likely(map)) return xdp_do_redirect_map(dev, xdp, xdp_prog, map); fwd = dev_get_by_index_rcu(dev_net(dev), index);