fio: provide an option for a startdelay range

[fio.git] / init.c

diff --git a/init.c b/init.c
index c3b33dccfaca2d538b39470532bc302be1544e5b..9d3c960870a89e0412094b5d5ee4ba6754462061 100644 (file)
--- a/init.c
+++ b/init.c
@@ -412,6 +412,26 @@ static int fixed_block_size(struct thread_options *o)
                o->min_bs[DDIR_READ] == o->min_bs[DDIR_TRIM];
 }
 
+
+static unsigned long long get_rand_start_delay(struct thread_data *td)
+{
+       unsigned long long delayrange;
+       unsigned long r;
+
+       delayrange = td->o.start_delay_high - td->o.start_delay;
+
+       if (td->o.use_os_rand) {
+               r = os_random_long(&td->delay_state);
+               delayrange = (unsigned long long) ((double) delayrange * (r / (OS_RAND_MAX + 1.0)));
+       } else {
+               r = __rand(&td->__delay_state);
+               delayrange = (unsigned long long) ((double) delayrange * (r / (FRAND_MAX + 1.0)));
+       }
+
+       delayrange += td->o.start_delay;
+       return delayrange;
+}
+
 /*
  * Lazy way of fixing up options that depend on each other. We could also
  * define option callback handlers, but this is easier.
@@ -496,6 +516,9 @@ static int fixup_options(struct thread_data *td)
        if (!o->file_size_high)
                o->file_size_high = o->file_size_low;
 
+       if (o->start_delay_high)
+               o->start_delay = get_rand_start_delay(td);
+
        if (o->norandommap && o->verify != VERIFY_NONE
            && !fixed_block_size(o))  {
                log_err("fio: norandommap given for variable block sizes, "
@@ -711,6 +734,7 @@ static void td_fill_rand_seeds_os(struct thread_data *td)
 
        os_random_seed(td->rand_seeds[FIO_RAND_FILE_SIZE_OFF], &td->file_size_state);
        os_random_seed(td->rand_seeds[FIO_RAND_TRIM_OFF], &td->trim_state);
+       os_random_seed(td->rand_seeds[FIO_RAND_START_DELAY], &td->delay_state);
 
        if (!td_random(td))
                return;
@@ -736,6 +760,7 @@ static void td_fill_rand_seeds_internal(struct thread_data *td)
 
        init_rand_seed(&td->__file_size_state, td->rand_seeds[FIO_RAND_FILE_SIZE_OFF]);
        init_rand_seed(&td->__trim_state, td->rand_seeds[FIO_RAND_TRIM_OFF]);
+       init_rand_seed(&td->__delay_state, td->rand_seeds[FIO_RAND_START_DELAY]);
 
        if (!td_random(td))
                return;