zipf/pareto/gauss: hash cleanup

[fio.git] / lib / zipf.c

diff --git a/lib/zipf.c b/lib/zipf.c
index 9b6ce6334836baa1f0f3c0c238da24f319ad4c3b..681df70069ac27419b4545dcbac0ee2de81fdbee 100644 (file)
--- a/lib/zipf.c
+++ b/lib/zipf.c
@@ -11,7 +11,7 @@
 #include "../minmax.h"
 #include "../hash.h"
 
-#define ZIPF_MAX_GEN   10000000
+#define ZIPF_MAX_GEN   10000000UL
 
 static void zipf_update(struct zipf_state *zs)
 {
@@ -23,7 +23,7 @@ static void zipf_update(struct zipf_state *zs)
         * 10M max, that should be doable in 1-2s on even slow machines.
         * Precision will take a slight hit, but nothing major.
         */
-       to_gen = min(zs->nranges, ZIPF_MAX_GEN);
+       to_gen = min(zs->nranges, (uint64_t) ZIPF_MAX_GEN);
 
        for (i = 0; i < to_gen; i++)
                zs->zetan += pow(1.0 / (double) (i + 1), zs->theta);
@@ -35,7 +35,7 @@ static void shared_rand_init(struct zipf_state *zs, unsigned long nranges,
        memset(zs, 0, sizeof(*zs));
        zs->nranges = nranges;
 
-       init_rand_seed(&zs->rand, seed);
+       init_rand_seed(&zs->rand, seed, 0);
        zs->rand_off = __rand(&zs->rand);
 }
 
@@ -59,7 +59,7 @@ unsigned long long zipf_next(struct zipf_state *zs)
        alpha = 1.0 / (1.0 - zs->theta);
        eta = (1.0 - pow(2.0 / n, 1.0 - zs->theta)) / (1.0 - zs->zeta2 / zs->zetan);
 
-       rand_uni = (double) __rand(&zs->rand) / (double) FRAND_MAX;
+       rand_uni = (double) __rand(&zs->rand) / (double) FRAND32_MAX;
        rand_z = rand_uni * zs->zetan;
 
        if (rand_z < 1.0)
@@ -69,7 +69,12 @@ unsigned long long zipf_next(struct zipf_state *zs)
        else
                val = 1 + (unsigned long long)(n * pow(eta*rand_uni - eta + 1.0, alpha));
 
-       return (__hash_u64(val - 1) + zs->rand_off) % zs->nranges;
+       val--;
+
+       if (!zs->disable_hash)
+               val = __hash_u64(val);
+
+       return (val + zs->rand_off) % zs->nranges;
 }
 
 void pareto_init(struct zipf_state *zs, unsigned long nranges, double h,
@@ -81,8 +86,18 @@ void pareto_init(struct zipf_state *zs, unsigned long nranges, double h,
 
 unsigned long long pareto_next(struct zipf_state *zs)
 {
-       double rand = (double) __rand(&zs->rand) / (double) FRAND_MAX;
-       unsigned long long n = zs->nranges - 1;
+       double rand = (double) __rand(&zs->rand) / (double) FRAND32_MAX;
+       unsigned long long n;
+
+       n = (zs->nranges - 1) * pow(rand, zs->pareto_pow);
+
+       if (!zs->disable_hash)
+               n = __hash_u64(n);
 
-       return (__hash_u64(n * pow(rand, zs->pareto_pow)) + zs->rand_off) % zs->nranges;
+       return (n + zs->rand_off)  % zs->nranges;
+}
+
+void zipf_disable_hash(struct zipf_state *zs)
+{
+       zs->disable_hash = true;
 }