diff --git a/arch/powerpc/mm/mmap_64.c b/arch/powerpc/mm/mmap_64.c
index 5a783d8e8e8e757719f5b055cf8142d56becc1d9..67a42ed0d2fc8408c7ecb197a3c5bf58c5bee6df 100644
--- a/arch/powerpc/mm/mmap_64.c
+++ b/arch/powerpc/mm/mmap_64.c
@@ -53,14 +53,6 @@ static inline int mmap_is_legacy(void)
 	return sysctl_legacy_va_layout;
 }
 
-/*
- * Since get_random_int() returns the same value within a 1 jiffy window,
- * we will almost always get the same randomisation for the stack and mmap
- * region. This will mean the relative distance between stack and mmap will
- * be the same.
- *
- * To avoid this we can shift the randomness by 1 bit.
- */
 static unsigned long mmap_rnd(void)
 {
 	unsigned long rnd = 0;
@@ -68,11 +60,11 @@ static unsigned long mmap_rnd(void)
 	if (current->flags & PF_RANDOMIZE) {
 		/* 8MB for 32bit, 1GB for 64bit */
 		if (is_32bit_task())
-			rnd = (long)(get_random_int() % (1<<(22-PAGE_SHIFT)));
+			rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT)));
 		else
-			rnd = (long)(get_random_int() % (1<<(29-PAGE_SHIFT)));
+			rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT)));
 	}
-	return (rnd << PAGE_SHIFT) * 2;
+	return rnd << PAGE_SHIFT;
 }
 
 static inline unsigned long mmap_base(void)
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index 441521ad8a3febfc9a91f7dbc5cdabb01690d591..232df9949530f3d95c3c95385a62d45402c6d042 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -368,11 +368,11 @@ static unsigned long mmap_rnd(void)
 	if (current->flags & PF_RANDOMIZE) {
 		unsigned long val = get_random_int();
 		if (test_thread_flag(TIF_32BIT))
-			rnd = (val % (1UL << (22UL-PAGE_SHIFT)));
+			rnd = (val % (1UL << (23UL-PAGE_SHIFT)));
 		else
-			rnd = (val % (1UL << (29UL-PAGE_SHIFT)));
+			rnd = (val % (1UL << (30UL-PAGE_SHIFT)));
 	}
-	return (rnd << PAGE_SHIFT) * 2;
+	return rnd << PAGE_SHIFT;
 }
 
 void arch_pick_mmap_layout(struct mm_struct *mm)