amend from 5_MS to 4_MS. I had misunderstanding that Linux kernel constant HZ is 100, 200 or 1000. But it should have been 100, 250 or 1000
#if !defined(MRBC_TICK_UNIT)
#define MRBC_TICK_UNIT_1_MS 1
#define MRBC_TICK_UNIT_2_MS 2
-#define MRBC_TICK_UNIT_5_MS 5
+#define MRBC_TICK_UNIT_4_MS 4
#define MRBC_TICK_UNIT_10_MS 10
// You may have to configure 2 ms or larger if you use
// POSIX or microcontroller whose native tick time is
