From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Sun, 20 Dec 2009 08:13:38 +0000 (-0800)
Subject: kernel - add hashinit_ext() and phashinit_ext()
X-Git-Tag: v2.7.1~272
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/c02197ac4398205f5d55cbb345e14c21e70d8c3b

kernel - add hashinit_ext() and phashinit_ext()

* Add hashinit_ext() and phashinit_ext(), extended versions of
  hashinit() and phashinit() which take a structure size and zero
  the array instead of assuming it is only an array of LIST_HEAD's.
---

diff --git a/sys/kern/kern_subr.c b/sys/kern/kern_subr.c
index 5968f852cc..a8a2b8be51 100644
--- a/sys/kern/kern_subr.c
+++ b/sys/kern/kern_subr.c
@@ -268,6 +268,28 @@ hashinit(int elements, struct malloc_type *type, u_long *hashmask)
 	return (hashtbl);
 }
 
+/*
+ * This is a newer version which allocates a hash table of structures.
+ *
+ * The returned array will be zero'd.  The caller is responsible for
+ * initializing the structures.
+ */
+void *
+hashinit_ext(int elements, size_t size, struct malloc_type *type,
+	     u_long *hashmask)
+{
+	long hashsize;
+	void *hashtbl;
+
+	if (elements <= 0)
+		panic("hashinit: bad elements");
+	for (hashsize = 2; hashsize < elements; hashsize <<= 1)
+		continue;
+	hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK | M_ZERO);
+	*hashmask = hashsize - 1;
+	return (hashtbl);
+}
+
 static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
 			2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
 			7159, 7673, 8191, 12281, 16381, 24571, 32749 };
@@ -299,6 +321,35 @@ phashinit(int elements, struct malloc_type *type, u_long *nentries)
 	return (hashtbl);
 }
 
+/*
+ * This is a newer version which allocates a hash table of structures
+ * in a prime-number size.
+ *
+ * The returned array will be zero'd.  The caller is responsible for
+ * initializing the structures.
+ */
+void *
+phashinit_ext(int elements, size_t size, struct malloc_type *type,
+	      u_long *nentries)
+{
+	long hashsize;
+	void *hashtbl;
+	int i;
+
+	if (elements <= 0)
+		panic("phashinit: bad elements");
+	for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
+		i++;
+		if (i == NPRIMES)
+			break;
+		hashsize = primes[i];
+	}
+	hashsize = primes[i - 1];
+	hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK | M_ZERO);
+	*nentries = hashsize;
+	return (hashtbl);
+}
+
 /*
  * Copyin an iovec.  If the iovec array fits, use the preallocated small
  * iovec structure.  If it is too big, dynamically allocate an iovec array
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 4b04fc46d7..a9fddd49fa 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -151,6 +151,10 @@ int	seltrue (cdev_t dev, int which);
 int	ureadc (int, struct uio *);
 void	*hashinit (int count, struct malloc_type *type, u_long *hashmask);
 void	*phashinit (int count, struct malloc_type *type, u_long *nentries);
+void	*hashinit_ext (int count, size_t size,
+			struct malloc_type *type, u_long *hashmask);
+void	*phashinit_ext (int count, size_t size,
+			struct malloc_type *type, u_long *nentries);
 
 int	cpu_sanitize_frame (struct trapframe *);
 int	cpu_sanitize_tls (struct savetls *);