From: Jens Axboe <axboe@fb.com>
Date: Tue, 17 May 2016 01:18:09 +0000 (-0600)
Subject: zipf/pareto/gauss: hash cleanup
X-Git-Tag: fio-2.10~23
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=8c5e96a4ee7004b2982b5d5247ecea1cb96bccb7

zipf/pareto/gauss: hash cleanup

Signed-off-by: Jens Axboe <axboe@fb.com>
---

diff --git a/lib/gauss.c b/lib/gauss.c
index 48e2fbfe..f974490f 100644
--- a/lib/gauss.c
+++ b/lib/gauss.c
@@ -39,7 +39,7 @@ unsigned long long gauss_next(struct gauss_state *gs)
 	}
 
 	if (!gs->disable_hash)
-		return __hash_u64(sum) % gs->nranges;
+		sum = __hash_u64(sum);
 
 	return sum % gs->nranges;
 }
diff --git a/lib/zipf.c b/lib/zipf.c
index 8b581faf..681df700 100644
--- a/lib/zipf.c
+++ b/lib/zipf.c
@@ -69,10 +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));
 
+	val--;
+
 	if (!zs->disable_hash)
-		return (__hash_u64(val - 1) + zs->rand_off) % zs->nranges;
+		val = __hash_u64(val);
 
-	return (val - 1 + zs->rand_off) % zs->nranges;
+	return (val + zs->rand_off) % zs->nranges;
 }
 
 void pareto_init(struct zipf_state *zs, unsigned long nranges, double h,
@@ -85,12 +87,14 @@ 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) FRAND32_MAX;
-	unsigned long long n = zs->nranges - 1;
+	unsigned long long n;
+
+	n = (zs->nranges - 1) * pow(rand, zs->pareto_pow);
 
 	if (!zs->disable_hash)
-		return (__hash_u64(n * pow(rand, zs->pareto_pow)) + zs->rand_off) % zs->nranges;
+		n = __hash_u64(n);
 
-	return (unsigned long long) (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)