From: Jack Lange <jarusl@cs.northwestern.edu>
Date: Tue, 14 Apr 2009 23:26:25 +0000 (-0500)
Subject: removed floating poing operations from hashtable, load factors are now precomputed
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=commitdiff_plain;h=0dc6c1ec345d5c48e348b7e6532e5dcec00fa2ff

removed floating poing operations from hashtable, load factors are now precomputed
---

diff --git a/palacios/include/palacios/vmm_string.h b/palacios/include/palacios/vmm_string.h
index 975a3d1..607130d 100644
--- a/palacios/include/palacios/vmm_string.h
+++ b/palacios/include/palacios/vmm_string.h
@@ -56,10 +56,6 @@ char *strrchr(const char *s, int c);
 char *strpbrk(const char *s, const char *accept);
 
 
-double v3_ceil(double x);
-
-
-
 #endif // !__V3VEE__
 
 #endif  /* STRING_H */
diff --git a/palacios/src/palacios/vmm_hashtable.c b/palacios/src/palacios/vmm_hashtable.c
index fe74dc7..ce0bee2 100644
--- a/palacios/src/palacios/vmm_hashtable.c
+++ b/palacios/src/palacios/vmm_hashtable.c
@@ -187,9 +187,19 @@ static const uint_t primes[] = {
     805306457, 1610612741 };
 
 
+// this assumes that the max load factor is .65
+static const uint_t load_factors[] = {
+    35, 64, 126, 253,
+    500, 1003, 2002, 3999,
+    7988, 15986, 31953, 63907,
+    127799, 255607, 511182, 1022365,
+    2044731, 4089455, 8178897, 16357798,
+    32715575, 65431158, 130862298, 261724573,
+    523449198, 1046898282 };
+
 const uint_t prime_table_length = sizeof(primes) / sizeof(primes[0]);
 
-const float max_load_factor = 0.65;
+
 
 /*****************************************************************************/
 struct hashtable * create_hashtable(uint_t min_size,
@@ -233,7 +243,7 @@ struct hashtable * create_hashtable(uint_t min_size,
     htable->entry_count   = 0;
     htable->hash_fn       = hash_fn;
     htable->eq_fn         = eq_fn;
-    htable->load_limit    = (uint_t) v3_ceil((double)(size * max_load_factor));
+    htable->load_limit    = load_factors[prime_index];
 
     return htable;
 }
@@ -317,7 +327,7 @@ static int hashtable_expand(struct hashtable * htable) {
 
     htable->table_length = new_size;
 
-    htable->load_limit   = (uint_t) v3_ceil(new_size * max_load_factor);
+    htable->load_limit   = load_factors[htable->prime_index];
 
     return -1;
 }
diff --git a/palacios/src/palacios/vmm_string.c b/palacios/src/palacios/vmm_string.c
index 77cee82..efe5a7d 100644
--- a/palacios/src/palacios/vmm_string.c
+++ b/palacios/src/palacios/vmm_string.c
@@ -60,17 +60,6 @@
 #include <palacios/vmm.h>
 
 
-
-static float e = 0.00000001;
-
-double v3_ceil(double x) {
-    if ((double)(x - (int)x) == 0) {
-	return (int)x;
-    }
-    return (int)(x + e) + 1;
-}
-
-
 #if NEED_MEMSET
 void* memset(void* s, int c, size_t n)
 {