rand: add 64-bit tausworthe variant with a 2^258 cycle

[fio.git] / filesetup.c

diff --git a/filesetup.c b/filesetup.c
index cf8ae94c86b83c516411396b336f720e5ab03931..f4324e23e4f328e4d88fcb3e9952d5333a36b706 100644 (file)
--- a/filesetup.c
+++ b/filesetup.c
@@ -267,11 +267,13 @@ error:
 static unsigned long long get_rand_file_size(struct thread_data *td)
 {
        unsigned long long ret, sized;
+       uint64_t frand_max;
        unsigned long r;
 
+       frand_max = rand_max(&td->file_size_state);
        r = __rand(&td->file_size_state);
        sized = td->o.file_size_high - td->o.file_size_low;
-       ret = (unsigned long long) ((double) sized * (r / (FRAND_MAX + 1.0)));
+       ret = (unsigned long long) ((double) sized * (r / (frand_max + 1.0)));
        ret += td->o.file_size_low;
        ret -= (ret % td->o.rw_min_bs);
        return ret;