From 80020aecd05f49119bfeaec130105f3890a5258a Mon Sep 17 00:00:00 2001
From: tedu <>
Date: Wed, 20 Jun 2012 13:13:15 +0000
Subject: two small fixes to free page cache.  first, we need two nibbles of
 random in order to span the the entire cache.  second, on free use the same
 offset to put things in the cache instead of always starting at zero. ok otto

---
 src/lib/libc/stdlib/malloc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'src/lib')

diff --git a/src/lib/libc/stdlib/malloc.c b/src/lib/libc/stdlib/malloc.c
index 6f646934b2..92efd7d68b 100644
--- a/src/lib/libc/stdlib/malloc.c
+++ b/src/lib/libc/stdlib/malloc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: malloc.c,v 1.142 2012/06/18 17:03:51 matthew Exp $	*/
+/*	$OpenBSD: malloc.c,v 1.143 2012/06/20 13:13:15 tedu Exp $	*/
 /*
  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
  *
@@ -317,7 +317,7 @@ unmap(struct dir_info *d, void *p, size_t sz)
 	rsz = mopts.malloc_cache - d->free_regions_size;
 	if (psz > rsz)
 		tounmap = psz - rsz;
-	offset = getrnibble();
+	offset = getrnibble() + getrnibble() << 4;
 	for (i = 0; tounmap > 0 && i < mopts.malloc_cache; i++) {
 		r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)];
 		if (r->p != NULL) {
@@ -337,7 +337,7 @@ unmap(struct dir_info *d, void *p, size_t sz)
 	if (tounmap > 0)
 		wrterror("malloc cache underflow", NULL);
 	for (i = 0; i < mopts.malloc_cache; i++) {
-		r = &d->free_regions[i];
+		r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)];
 		if (r->p == NULL) {
 			if (mopts.malloc_hint)
 				madvise(p, sz, MADV_FREE);
@@ -398,7 +398,7 @@ map(struct dir_info *d, size_t sz, int zero_fill)
 		/* zero fill not needed */
 		return p;
 	}
-	offset = getrnibble();
+	offset = getrnibble() + getrnibble() << 4;
 	for (i = 0; i < mopts.malloc_cache; i++) {
 		r = &d->free_regions[(i + offset) & (mopts.malloc_cache - 1)];
 		if (r->p != NULL) {
-- 
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