ping
pthread_t ping;
CHECKr(pthread_create(&ping, NULL, ping_thread, NULL));
n = write(wp, ping, sizeof(ping));
if (n != sizeof(ping))
n, sizeof(ping));
const char ping[] = "ping";
if (strcmp(ping, buf))
errx(1, "[c] read: %s != %s\n", ping, buf);
on_each_cpu(ping, NULL, 1);
ping(ypdb);
int ping(struct _dom_binding *ypdb);