scripts

commit 64c09e5c2a77312abc0c4e18cdc3751e93748089
parent a6f66e1592b3224b5c95660906a1a7e829d884f3
Author: sin <sin@2f30.org>
Date:   Fri,  2 Aug 2013 11:03:33 +0100

Use sbrk() in alloc_object()

We keep all the rbtree nodes close together for better
cache coherency.

Diffstat:
M
random/rballoc.c
 | 
22
+++++++++++-----------

1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/random/rballoc.c b/random/rballoc.c
@@ -71,22 +71,23 @@ dump_free_tree(void)
 			__func__, n->buf, n->siz);
 }
 
+struct sbrk_descr {
+	void *base;
+	size_t siz;
+};
+
+static struct sbrk_descr sd;
+
 static inline void *
 alloc_object(size_t siz)
 {
 	void *p;
 
-	p = mmap(0, siz, PROT_READ | PROT_WRITE,
-		 MAP_PRIVATE | MAP_ANON, -1, 0);
-	if (p == MAP_FAILED)
+	sd.base = sbrk(siz);
+	if (sd.base == (void *)-1)
 		return NULL;
-	return p;
-}
-
-static inline void
-free_object(void *p, size_t siz)
-{
-	munmap(p, siz);
+	sd.siz += siz;
+	return sd.base;
 }
 
 /* Allocate a memory block.  Round `siz' to be
@@ -127,7 +128,6 @@ malloc(size_t siz)
 		}
 		p = alloc_block(siz);
 		if (!p) {
-			free_object(an, sizeof(*an));
 			unlock(&rblock);
 			return NULL;
 		}