xdp: tracing: Hide some xdp events under CONFIG_BPF_SYSCALL

The events xdp_cpumap_kthread, xdp_cpumap_enqueue and xdp_devmap_xmit are
only called when CONFIG_BPF_SYSCALL is defined.  As each event can take up
to 5K regardless if they are used or not, it's best not to define them
when they are not used. Add #ifdef around these events when they are not
used.

Acked-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

Author: rostedt

include/trace/events/xdp.h

@@ -168,6 +168,7 @@ DEFINE_EVENT(xdp_redirect_template, xdp_redirect_err,
 #define _trace_xdp_redirect_map_err(dev, xdp, to, map_type, map_id, index, err) \
 	 trace_xdp_redirect_err(dev, xdp, to, err, map_type, map_id, index)
 
+#ifdef CONFIG_BPF_SYSCALL
 TRACE_EVENT(xdp_cpumap_kthread,
 
 	TP_PROTO(int map_id, unsigned int processed,  unsigned int drops,
@@ -281,6 +282,7 @@ TRACE_EVENT(xdp_devmap_xmit,
 		  __entry->sent, __entry->drops,
 		  __entry->err)
 );
+#endif /* CONFIG_BPF_SYSCALL */
 
 /* Expect users already include <net/xdp.h>, but not xdp_priv.h */
 #include <net/xdp_priv.h>