Time Slice Value

Question Text

Using the man page, what is the time slice used by the scheduler in libult.so?

Question Answers

• 100 milliseconds

• 10 microseconds

• 100 microseconds

• 10 milliseconds

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The code we're interested in lies in the function init_profiling_timer():

const struct itimerval timer = {
    { 0, 10000 },
    { 0, 1 }  // arms the timer as soon as possible
};

The man page gives the following definition the struct itimerval:

struct itimerval {
    struct timeval it_interval; /* Interval for periodic timer */
    struct timeval it_value;    /* Time until next expiration */
};

struct timeval {
    time_t      tv_sec;         /* seconds */
    suseconds_t tv_usec;        /* microseconds */
};

So when constructing the timer variable, { 0, 10000 } means 0 seconds and 10000 microseconds, i.e. 0 seconds and 10 milliseconds.