Actually commit the example

Signed-off-by: Alun Evans <[email protected]>

examples/kprobe_percpu/main.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/cilium/ebpf"
+	"github.com/cilium/ebpf/internal"
 	"github.com/cilium/ebpf/link"
 	"github.com/cilium/ebpf/rlimit"
 )
@@ -51,18 +52,22 @@ func main() {
 
 	log.Println("Waiting for events..")
 
+	possibleCPUs, err := internal.PossibleCPUs()
+	if err != nil {
+		log.Fatalf("possible cpus: %v", err)
+	}
 	batch := true
 	for range ticker.C {
 		var all_cpu_value []uint64
 		if batch {
 			var nextKeyOut uint32
 			lookupKeys := make([]uint32, 2)
-			lookupValues := make([][]uint64, 2)
+			lookupValues := make([]uint64, 2*possibleCPUs)
 			count, err := objs.KprobeMap.BatchLookup(nil, &nextKeyOut, lookupKeys, lookupValues, &ebpf.BatchOptions{})
 			if count != 1 {
 				log.Fatalf("batch reading map: %v", err)
 			}
-			all_cpu_value = lookupValues[0]
+			all_cpu_value = lookupValues[0:possibleCPUs]
 		} else {
 			if err := objs.KprobeMap.Lookup(mapKey, &all_cpu_value); err != nil {
 				log.Fatalf("reading map: %v", err)