CLK_TCK
return (CLK_TCK);
#define CONVTCK(r) (r.tv_sec * CLK_TCK + r.tv_usec / (1000000 / CLK_TCK))
return (ts.tv_sec * CLK_TCK + ts.tv_nsec / (1000000000 / CLK_TCK));
sysconf_row(CLK_TCK)