On Wed, Jun 29, 2022 at 4:38 PM Maciej Fijalkowski
<maciej.fijalkowski@xxxxxxxxx> wrote:
>
> Currently bpf_link probe is done for each call of xsk_socket__create().
> For cases where xsk context was previously created and current socket
> creation uses it, has_bpf_link will be overwritten, where it has already
> been initialized.
>
> Optimize this by moving the query to the xsk_create_ctx() so that when
> xsk_get_ctx() finds a ctx then no further bpf_link probes are needed.
This would be a good optimization to libxdp too.
Acked-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
> ---
> tools/testing/selftests/bpf/xsk.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/xsk.c b/tools/testing/selftests/bpf/xsk.c
> index eb50c3f336f8..fa13d2c44517 100644
> --- a/tools/testing/selftests/bpf/xsk.c
> +++ b/tools/testing/selftests/bpf/xsk.c
> @@ -958,6 +958,7 @@ static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk,
> ctx->fill = fill;
> ctx->comp = comp;
> list_add(&ctx->list, &umem->ctx_list);
> + ctx->has_bpf_link = xsk_probe_bpf_link();
> return ctx;
> }
>
> @@ -1059,7 +1060,6 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
> }
> }
> xsk->ctx = ctx;
> - xsk->ctx->has_bpf_link = xsk_probe_bpf_link();
>
> if (rx && !rx_setup_done) {
> err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING,
> --
> 2.27.0
>
