HZ
#define HZ 100
#define HZ 1000
#define HZ 100
#define HZ 100
#undef HZ /* in case they've included <sys/param.h> */
#define HZ ((int)sysconf(_SC_CLK_TCK)) /* ticks/second of the clock */
#define HZ 100
#define HZ (drv_hztousec(1))
#define HZ ((clock_t)_sysconf(_SC_CLK_TCK))