kernel/sysctl.c     | 2 --
 mm/page-writeback.c | 7 ++++++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index b2f06f3c6a3f..411da56cd732 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1406,7 +1406,6 @@ static struct ctl_table vm_table[] = {
 		.extra1		= &zero,
 	},
 #endif
-#ifdef CONFIG_HIGHMEM
 	{
 		.procname	= "highmem_is_dirtyable",
 		.data		= &vm_highmem_is_dirtyable,
@@ -1416,7 +1415,6 @@ static struct ctl_table vm_table[] = {
 		.extra1		= &zero,
 		.extra2		= &one,
 	},
-#endif
 	{
 		.procname	= "scan_unevictable_pages",
 		.data		= &scan_unevictable_pages,
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 63807583d8e8..b3bce1cd59d5 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -241,8 +241,13 @@ static unsigned long global_dirtyable_memory(void)
 	x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
 	x -= min(x, dirty_balance_reserve);
 
-	if (!vm_highmem_is_dirtyable)
+	if (!vm_highmem_is_dirtyable) {
+		const unsigned long GB_pages = 1024*1024*1024 / PAGE_SIZE;
+
 		x -= highmem_dirtyable_memory(x);
+		if (x > GB_pages)
+			x = GB_pages;
+	}
 
 	return x + 1;	/* Ensure that we never return 0 */
 }