On 14/11/2019 17.38, Pierre Morel wrote: [...] >>> +static char buffer[4096]; >>> + >>> +static void delay(int d) >>> +{ >>> + int i, j; >>> + >>> + while (d--) >>> + for (i = 1000000; i; i--) >>> + for (j = 1000000; j; j--) >>> + ; >>> +} >> You could set a timer. > > Hum, do we really want to do this? I'm pretty sure that the compiler optimizes empty loops away. Maybe have a look at the disassembly of your delay function... Anyway, it's likely better to use STCK and friends to get a proper timing. You could move get_clock_ms() from s390x/intercept.c to the lib/s390x folder and then use that function here. Thomas