xdp: Remove map_to_flush and map swap detection (332f22a6) · Commits · 戴 / test

Now that all XDP maps that can be used with bpf_redirect_map() tracks entries to be flushed in a global fashion, there is not need to track that the map has changed and flush from xdp_do_generic_map() anymore. All entries will be flushed in xdp_do_flush_map(). This means that the map_to_flush can be removed, and the corresponding checks. Moving the flush logic to one place, xdp_do_flush_map(), give a bulking behavior and performance boost. Signed-off-by:

Björn Töpel <bjorn.topel@intel.com> Signed-off-by:

Alexei Starovoitov <ast@kernel.org> Acked-by:

Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20191219061006.21980-8-bjorn.topel@gmail.com

include/linux/filter.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -592,7 +592,6 @@ struct bpf_redirect_info {
		u32 tgt_index;
		void *tgt_value;
		struct bpf_map *map;
		struct bpf_map *map_to_flush;
		u32 kern_flags;
		};

net/core/filter.c

+3 −24

Original line number	Diff line number	Diff line
		@@ -3547,26 +3547,9 @@ static int __bpf_tx_xdp_map(struct net_device dev_rx, void fwd,

		void xdp_do_flush_map(void)
		{
		struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
		struct bpf_map *map = ri->map_to_flush;

		ri->map_to_flush = NULL;
		if (map) {
		switch (map->map_type) {
		case BPF_MAP_TYPE_DEVMAP:
		case BPF_MAP_TYPE_DEVMAP_HASH:
		__dev_map_flush();
		break;
		case BPF_MAP_TYPE_CPUMAP:
		__cpu_map_flush();
		break;
		case BPF_MAP_TYPE_XSKMAP:
		__xsk_map_flush();
		break;
		default:
		break;
		}
		}
		}
		EXPORT_SYMBOL_GPL(xdp_do_flush_map);

		@@ -3615,14 +3598,10 @@ static int xdp_do_redirect_map(struct net_device dev, struct xdp_buff xdp,
		ri->tgt_value = NULL;
		WRITE_ONCE(ri->map, NULL);

		if (ri->map_to_flush && unlikely(ri->map_to_flush != map))
		xdp_do_flush_map();

		err = __bpf_tx_xdp_map(dev, fwd, map, xdp);
		if (unlikely(err))
		goto err;

		ri->map_to_flush = map;
		_trace_xdp_redirect_map(dev, xdp_prog, fwd, map, index);
		return 0;
		err:

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